Elisabeth C. Miller Library logo Miller Library Home UW Botanic Gardens Home UW Botanic Gardens Home book graphic

3501 NE 41st Street, Seattle, WA 98195 | (206) 543 0415 | Open Monday 9-8; Tuesday - Friday 9-5; Saturday 9-3

Gardening Answers Knowledgebase

Search Results for ' '

PAL Questions: 833 - Garden Tools: 346 - Recommended Websites: 680

Display all answers | Hide all answers


1   |   2   |   3   |   4   |   5   |   6   |   7   |   8   |   9      »      [40]

 

Keywords: Insect pests--Control, Trees--Diseases and pests, Pesticides

PAL Question:

What is the latest method of eradication for the mountain pine beetle, Dendroctonus ponderosae, that is rampant in western Canada?

View Answer:

In the northwestern U.S., Washington State University Extension's Forest Health Notes states that the focus has shifted from using pesticides to taking preventive measures:
Excerpt:
Control methods have shifted away from direct control (e.g. spraying, felling, burning) and towards prevention of outbreaks. This course of action was chosen after thoroughly exploring direct control measures for nearly a century and arriving at a simple conclusion: They don't work. It is possible to prevent infestation with penetrating sprays on individual, high value trees such as those in campgrounds and near houses, but they need to be applied before the tree is infected and the cost of such treatments is prohibitive for any large-scale application.
Once a mountain pine beetle outbreak begins to spread, it can be stopped by thinning the stand ahead of the edge of the outbreak. This is because outbreaks expand on a tree to tree basis where the incoming beetles switch their attacks from a recently attacked-stem to the next largest tree. More importantly, infestations can be prevented by thinning stands before crown closure, an operation that not only increases the vigor of the residual stand, but also prevents the spread of an outbreak if individual trees have been attacked.
Mountain pine beetles are a natural part of western ecosystems, and for this reason will never be completely eradicated (nor should they be, as they serve to create small stand openings which are important for biodiversity of both flora and fauna). As such, the death of a few trees on your property doesn't necessarily mean an epidemic is getting started; check your trees for root disease symptoms. To maintain mountain pine beetles at their normal levels, predisposing factors for outbreak must be removed. Some of these, such as environmental stresses, are not possible to control. However, many stresses are related to stand management practices. First and foremost, two situations need to be addressed: root disease centers and overstocked stands. More details about treatment for root disease centers have been given in other WSU Cooperative Extension "Forest Health Notes;" in summary, they need to be identified and planted with resistant species. Overstocking causes trees to compete for water, light and nutrients, and thus weakens their defenses against bark beetle attack. To minimize stand stresses and maintain vigorous growing conditions, stand managers should: (adapted from Berryman: Forest Insects, 1986).

Natural Resources Canada has a task force on the mountain pine beetle. You might want to contact them for the latest update. Go to their mountain pine beetle website and follow the links for additional information, including how to contact CCoFI.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: genetically modified seeds, Weed control, Herbicides

PAL Question:

What can you tell me about the weed killer "Concern Weed Prevention Plus"?

View Answer:

This product is corn-gluten based, and it is not meant to work on weeds which are already growing, but on those which have yet to emerge (pre-emergent). Corn gluten meal has been promoted as an environmentally safer alternative to conventional herbicides, but there are still certain issues that bear considering. Research at Oregon State University showed that corn gluten meal did not prevent weed seed germination. Here is an excerpt from the study's findings:
"Corn gluten meal did not control any weeds in any trials under any circumstances over a two-year period. They found no evidence of pre- or post-emergence weed control in any of their trials. Because it contains 10 percent nitrogen, corn gluten meal proved to be a very effective fertilizer, causing lush, dense growth of turfgrass and of weeds in shrub beds."

Although corn gluten meal presents far fewer risks to human and animal health than conventional herbicide, a gardener who is attempting to use only organic methods might consider the source of the corn in these products, which is very likely to be genetically modified. A webpage no longer available from University of Wisconsin Master Gardeners addressed this question:
"Up to 60% of the commercial corn and soybeans in the United States is grown from GMO seed. Corn gluten sold as a preemergent herbicide may indeed contain GMO corn, but it has not yet been tested. Here's the twist. Corn gluten can reduce the need for traditional herbicides that have environmental side effects. It likely now contains GMO corn. It could be produced from non-GMO corn, but would likely be more expensive."

Washington State University professor of horticulture Linda Chalker-Scott has also written about "The Myth of Weed-Killing Gluten," and states that no research suggests this is an effective method of weed control in the Northwest. She recommends sub-irrigation, mulch, and soil solarization instead.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Arboretums and botanical gardens--Pacific Northwest, Arboretums and botanical gardens--Washington, Xeriscaping

PAL Question:

Where in Washington State can I find examples of public gardens designed to be drought-tolerant xeriscapes?

View Answer:

There are Master Gardener Demonstration Gardens around the state, such as Riverfront Park Demonstration Garden in Wenatchee. There is also a WaterWise demonstration garden in Woodinville.

There is a water-wise garden in the Bellevue Botanic Garden.

There is a native plant garden maintained by the Tacoma Garden Club at Point Defiance Park.

Seattle Tilth maintains several demonstration gardens, including the Good Shepherd Center in the Wallingford neighborhood in Seattle and Bradner Gardens Park at 29th Ave. S. and S. Grand Street, in south Seattle. While not exclusively xeriscapes, their gardens employ water-saving techniques.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Plant exchanges and donations, Paeonia, Seed exchanges

PAL Question:

Do you know of any plant share sites where I might find some peonies, for example? Or where I might post some stuff I have no place for?

View Answer:

Most reliable seed exchange programs require membership, but . . .

PEONIES:
If you are interested specifically in peony seeds, the American Peony Society and the Canadian Peony Society are excellent sources.

You might also consider contacting the Pacific Northwest Peony Society. They are fairly new (est. 1996) and might not have a seed exchange yet, but can be helpful with other information.

GENERAL:
The American Horticultural Society has an excellent seed exchange program (you must be a member to participate) for just about anything you could want.

DONATING PLANTS:
There are several places locally that list plants for donation.
Plant Amnesty has an Adopt-a-Plant program. Also, try the Pacific Northwest Garden Exchange at GardenWeb.

Season Winter
Date 2007-12-06
Link to this record only (permalink)


Keywords: Pruning shrubs, Rhododendron

PAL Question:

I need to know what to do with a rhododendron that has grown too big. I want to keep it, since it is a bookend to another plant. Can I cut it back, and if so, how far and when? Will it be okay and continue to bloom if I cut it back? Could you suggest something and also suggest a really good book on care, etc., for rhodies?

View Answer:

For general care, quick information is available at

1) The American Rhododendron Society, click on "Need Help Growing Rhododendrons?"

2) The Seattle Rhododendron Society, click on "Care and Maintenance of Rhododendrons."

For more extensive information, there are scores of great books. A good one that includes specifics about rhodies is Cass Turnbull's Guide to Pruning (Cass Turnbull, 2004). Plant Amnesty, founded by Turnbull, also has information on pruning an overgrown rhododendron.

You can also select one by thumbing through the paperbacks available at (almost) all nurseries. Sunset Publishing, American Horticultural Society and Ortho Books are reliable publishers.

As an aside, there were some ancient, neglected, potentially beautiful rhodies at my home. They were pruned slowly over 3 to 4 years and look great now. So, don't be shy!

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Dahlia

PAL Question:

I need to find a photo of the eyes on a dahlia tuber.

View Answer:

There is good information on growing dahlias, including an image of the location of the eye on a tuber, at the website of the American Dahlia Society. To find the eye, locate the point on the shoulder, or crown, of the tuber from which the plant grows. The blog of Lynch Creek Dahlias has good description and illustrations:
"Keep in mind that every dahlia tuber, to be viable, must have at least one eye, which you'll see as tiny pointed protrusions on or near the neck of the tuber (the neck is the tuber's connection to the central part of the root mass)."

Season Fall
Date 2007-12-06
Link to this record only (permalink)


Keywords: Flowering of plants, Seedlings--Transplanting, Germination, Brugmansia

PAL Question:

Can you give me specific directions on how to germinate Brugmansia seed and care for the seedlings. Also, at what age or size do these plants flower?

View Answer:

The following information is quoted from the book Brugmansia and Datura: Angels' Trumpets and Thorn Apples (by Ulrike and Hans-Geog Preissel, 2002, p. 74):

The fresh seed should be sown as early as possible, at temperatures between 64--79 F. Cover the seed with approximately 1/5 (.20) inch of humus, which must be kept wet.

The seed is relatively large and is pressed lightly into the hummus to ensure contact with the moist planting mix. Initially cover the seed box with a glass plate to provide optimal humidity. At temperatures around 68 F, the various species of Brugmansia germinate very differently. As a rule, germination takes between 10 and 20 days. The young seedlings can then be planted out directly into small containers.Young plants that are grown from seed go through an immature phase, easily recognized by the change in leaf shape. The plants do not reach flowering maturity until the end of this immature phase. The length of time before the first flowering varies with the species. On average, most Brugmansia flower for the first time when the plant is between 2.5--5 feet in size. If they are well cultivated, then they will usually reach this size in six to nine months.

Plants grown from seed can look very different. They differ not only in leaf shape and size, flower shape, color and size, but also in other traits, such as susceptibility to diseases or willingness to flower. The possibilities are almost endless and many interesting and valuable discoveries are undoubtedly waiting to be made....

Season All Season
Date 2006-12-14
Link to this record only (permalink)


Keywords: Plant patents and registrations

PAL Question:

Is there a published list of patented plants?

View Answer:

I was not able to find an accessible list of patented plants from the U.S. Patent and Trademark Office, but their website does provide information about plant patents. They also have a bookstore which sells printed "Index of Patents" issued in a particular year. Individual plant breeders may list their patented and patent-pending plants, as this example from PlantHaven shows. The plant breeders Proven Winners also have several informative pages about plant patents.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Botanical nomenclature

PAL Question:

Is there an online resource for tracking updates in plant taxonomy?

View Answer:

You may not be able to find up-to-the-minute, late-breaking changes, but you can search by plant family, genus, or species in the following online resources which are considered authoritative on plants and their scientific names:

1. You can download the USDA's Complete Plant List. You can search for plants by scientific or common name here as well.

2. The GRIN database (also maintained by the USDA) offers several searching options and provides information on changes for each plant retrieved.3. The International Plant Names Index also allows you to search for plants by scientific name; in addition, you can search for publications.

4. Here are two more name databases for plants in various parts of the world: Multilingual Multiscript Plant Name Database and Flora Europaea.

5. Missouri Botanical Garden's Tropicos website is another source of information on changes to plant names.

6. Here are two links to more information about taxonomy.

Kew Gardens has information about why plants change their names.

The Horticultural Taxonomy Group (HORTAX) was set up in 1988, with the objective of providing a forum for taxonomists and horticulturists in the British Isles who have an interest in the taxonomy and nomenclature of cultivated plants.

7. There is a journal called Taxon, available online to subscribers, and available to Miller Library patrons using the library's computers.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Lawns--Planting, Weed control, Lawns--Care and maintenance

PAL Question:

I am renovating a lawn that has been completely ignored for a long time--dandelions 3 per square foot, for example. I need to know if I should use something like weed-and-feed now to kill the 1000s of weeds and wait till spring to aerate, remove the top 1/2-inch of the lawn, fertilize and re-seed. Do I need to get on this before the first frost?

View Answer:

Regarding your questions about lawn renovation, I have found a few options for you:

1. If the weed-and-feed product is for pre-emergent weeds, this would not work on your lawn, which already has dandelions growing actively. If the product is post-emergent, it will kill the dandelions, but if you are planning to sow grass seed, you will need to wait before sowing (different products have different guidelines, so check the directions on the package carefully). According to The Lawn Bible (by David R. Mellor, 2003), you should also make sure that the herbicide will target the weeds you have. Do not spray in windy conditions, and only treat areas which need it.

Overuse of herbicide destroys valuable bacteria and insects in the soil, so prevention is the best: mow the lawn high, which will keep weeds from getting established, as they need light to thrive; don't scalp the lawn; water only when it is too difficult to press a screwdriver into the top 2 inches of the soil.

2. There are less toxic alternatives. Some sources say that corn gluten prevents weed seeds from sprouting. They must be wet to be activated. (It won't work on dandelions which are already thriving in your lawn.) There is a product called Organic Weed Stopper Plus Corn Gluten Meal (from Walt's Organic Fertilizer Company in Seattle) which can be used: they recommend March 15 for getting rid of crabgrass, and August 15 for fall dandelions. (Please note that subsequent research suggests corn gluten may be ineffective as a weed control method. See this Oregon State University study.)

According to Ann Lovejoy's book, The Handbook of Northwest Gardening, corn gluten should be spread at a rate of 20 pounds per 1,000 square feet of lawn. Do this two or three times a year (in spring and fall, with a summer booster as needed). For ongoing weed suppression, apply it in small amounts whenever you pull up weeds (make a paste of corn gluten and water).

3. The Lovejoy book also has a recipe for fall lawn renovation:
a. Mow the existing grass as short as possible.
b. Spread 1 inch of clean crushed quarter-ten gravel (not pea gravel) evenly over the entire surface.
c. Spread 1 inch of compost over the gravel.
d. Top-seed with a regionally appropriate blend if the lawn is thin and spotty.
e. Wait 6-7 weeks before mowing again.

A criticism of weed-and-feed products is that they will add excessive amounts of phosphorus to your lawn, which will actually encourage weed growth once the herbicide breaks down.

The Northwest Center for Alternatives to Pesticides has good information about controlling dandelions without using weed-and-feed products (originally published in the Journal of Pesticide Reform, Fall 2001).

And, Washington Toxics Coalition has information on an overall approach to weed control and lawn care

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Coffee, Compost

PAL Question:

I have a composting question: I work at a large hospital and would like to collect all of the used coffee grounds/filters from the countless pots throughout the hospital and use it (tons of it!) for compost. Could you create adequate compost with just coffee and probably straw to balance it?

View Answer:

The information below is quoted from an article by Bob Smith, Washington State University Master Gardener Program Manager, Thurston County, in The Gardener, Vol. 6, No. 4, Winter 1995-96):

"In 1995, three local coffee houses called WSU Extension in Thurston County [Washington] for advice on composting coffee grounds. With the exception of worm bin composting, we were unable to find much information. Our Master Composter and Master Gardener volunteers decided to experiment. They composted about 270 pounds of coffee grounds donated by local espresso bars. They fed roughly 60 pounds to worms while composting the rest in regular bins.

"If coffee grounds are not worms's food of choice, they certainly must be high on the list. In appreciation for a meal of ready-to-consume grounds, the worms produced excellent compost. Incorporate coffee grounds soon after brewing into your worm box. This reduced the possibility of the grounds souring and attracting pesky fruit flies.

"We also experimented by composting coffee grounds in three types of traditional bins:
1) an enclosed holding bin made of recycled plastic,
2) a three-level wire stacking bin, and
3) a large, round, wire holding bin. Our primary concern was whether the coffee grounds would attract pests.

"We incorporated the grounds over a four month period yet experienced only one problem: fruit flies showed up in the enclosed plastic bin almost immediately after we added coffee grounds. In open wire bins, the grounds tended to dry out quickly. Overall, though, we found coffee grounds easy to work with and satisfactory for composting.

"Coffee grounds have a carbon-to-nitrogen ratio of 20:1, roughly equivalent to that of grass clippings. After brewing, coffee grounds contain up to 2% nitrogen. For composting purposes, consider coffee grounds green material similar to grass clippings. For brown material, we used leaves and sawdust. In these trials, we used a formula of one part green material (coffee grounds alone or mixed with grass clippings) to two parts leaves, or four parts green material to one part sawdust."

In the Winter 2009 issue of Master Gardener, WSU Extension Horticulturist Linda Chalker-Scott recommends using a thin layer (half an inch or less) of coffee grounds as mulch, topping this with a thicker layer (4 inches) of coarser organic material such as wood chips. She also says that the optimal percentage of coffee grounds in total compost volume should be 10 to 20 percent, and no more. The pH of spent coffee grounds varies, and one cannot assume they are acidic.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Matteuccia, Ornamental ferns

PAL Question:

I have ostrich [deciduous] ferns [on the grounds I keep] and I was wondering if there is anything special that I should do for them for the winter. What I have been doing is putting ground up leaves in the bed, but beyond that, I'm not sure if there is anything else I should do.

View Answer:

Andrew MacHugh's book, The Cultivation of Ferns (1992) says the following (from p. 47):

"In autumn, a mulch of well-rotted leafmould, peat or bark chippings should be given to ferns planted in open sites. [...] In winter the fronds of deciduous ferns can be cut back to an inch above the crown. In areas subject to frost, the decayed fronds will provide some protection to the plant and should not be removed until the spring growth of new fronds shows signs of emerging."

Season Fall
Date 2006-02-26
Link to this record only (permalink)


Keywords: Rhamnus purshiana, Pyrus, Nyssa, Hovenia, Oxydendrum arboreum, Cornus nuttallii, Malus, Crataegus, Native plants--Care and maintenance, Trees--Pacific Northwest, Quercus, Multipurpose trees, Prunus, Acer

PAL Question:

Can you recommend some tree species (deciduous) that can have wet feet but will also tolerate dry conditions in the summer? The recommendations should be trees that are not too messy (no cottonwoods or alders, please) and not too big. I would like to plant some trees near a swale in my yard - so they could be sitting in soggy ground during the winter.

View Answer:

Following is a list of possibilities, most of which come from Water Conserving Plants for the Pacific Northwest West of the Cascades (by the N.W. Perennial Alliance, 1993). The list includes only trees that 1) thrive in soils which are waterlogged in the winter, and, 2) grow to less than 40 feet tall.

ACER (maple):
A. buergeranum (trident maple)
A. campestre (field maple)
A. ginnala (Amur maple)
A. circinatum (vine maple)
CORNUS nuttallii (western dogwood)
C. douglasii (black hawthorn)
C. monogyna
C. phaenopyrum (Washington thorn)
C. x lavallei (Carriere hawthorn)
HOVENIA dulcis (Japanese raisin tree)
MALUS fusca (Pacific crab apple)
NYSSA sylvatica (black gum)
OXYDENDRUM arboreum (sourwood)
PRUNUS (prune/plum/cherry):
P. virginiana var. melanocarpa (chokecherry)
P. emarginata (bitter cherry)
PYRUS (pear):
P. communis (common pear)
P. pyrifolia (Chinese pear, sand pear)
QUERCUS (oak):
Q. acutissima (sawtooth oak)
Q. imbricaria (shingle oak)
RHAMNUS purshiana (cascara)

Season Winter
Date 2006-05-23
Link to this record only (permalink)


Keywords: Color, Parrotia

PAL Question:

I have a Parrotia persica tree that has never developed the dramatic purple color that the Sunset Western Garden Book says it should have. Its leaves do turn gold in the fall. What nutrient is it missing? It gets full sun, and is at the top of a sloping area of lawn. I have wondered if the run-off could be leaching something from the soil.

Any suggestions?

View Answer:

According to this article in Fine Gardening online, Parrotia persica only has that purple color as the leaves emerge in spring:
"Reddish-purple when unfolding in spring, the leaves are a lustrous dark green in summer, and yellow to orange or scarlet in fall. Leaves hold their color for a long period. Older branches and trunks develop an exfoliating gray, green, white, and brown color that is a welcome asset in the winter garden. It grows successfully in Zones 4 to 8, tolerates sun and partial shade, and is easy to transplant. Often, vegetatively propagated forms offer more reliable fall color."

According to Dirr's Hardy Trees and Shrubs (Timber Press, 1997), there is some variability in the foliage color: "[...]the developing leaves are reddish-purple to bronze, maturing to lustrous dark green." I don't believe missing nutrients are the reason you are not seeing dramatic purple color but if you are concerned, you can do a soil test for any imbalances.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Mexican plants, Plant care, Deppea

PAL Question:

I have a plant, Deppea splendens, purchased through a special offer from Pacific Horticulture. It is a native of Mexico. This year (I've had it for about 2 years) it looks very healthy and has gotten quite a bit bigger. It is supposed to flower, but it has yet to do so for me. Any answers?

View Answer:

Deppea splendens is such a rare (previously almost extinct) plant that none of our standard sources have any cultural information. However, there was an article written about it in the April 2000 issue of Pacific Horticulture by Kathy Musial which mentions that it needs a frost-protected spot if it is to flower. The article recommends growing it in a container in colder regions so it may be brought into a sheltered area. Overly dry conditions will also cause the flowers to abort.

Excerpts from the article are included in University of British Columbia Botanical Garden's "Botany Photo of the Day" web page.

An article in UCLA Botanical Garden provides additional information about the plant.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Opuntia, Native plants--Washington, Cactaceae (Cactus family), Cactus

PAL Question:

Does the Opuntia fragilis in the Puget Sound carry a vernacular name of dune or shore prickly pear?

View Answer:

The most common vernacular name of the cactus Opuntia fragilis in Washington is brittle prickly pear. When I searched for dune or shore prickly pear, I found these common names connected with other species of Opuntia.

For more information about Opuntia fragilis, see the Washington Flora Checklist and the USDA Plant Profile.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Buchloe, Turfgrasses, Lawns

PAL Question:

I was interested in trying out buffalo grass (Buchloe dactyloides) 'Legacy' from High Country Gardens. I was wondering if you knew anyone who has tried growing it in the PNW (esp. Whidbey Island) and what they thought of its performance.

View Answer:

According to the Sunset Western Garden Book, buffalo grass is best suited to Sunset zones 1-3, 10, and 11. Whidbey Island is Sunset zone 5. While the Sunset book does not address 'Legacy' in particular, you may find that this grass is not the best choice for your location.

The Washington State Extension in Puyallup created a ranked list of good turf cultivars for Western Washington.

Additional information, from the Extension, about turfgrass.

Season All Season
Date 2007-12-06
Link to this record only (permalink)


Keywords: Zelkova, Xylosma, Thujopsis, Taxodium, Tamarix, Poa, Pennisetum, Casuarina, Baccharis, Festuca, Juglans, Alnus, Palms, Allergies

PAL Question:

What could cause sinus allergy symptoms every December?

View Answer:

According to Thomas Ogren's book, Allergy Free Gardening , the genera Alnus, Baccharis, Casuarina, Festuca, Pennisetum, Juglans, Poa, Tamarix, Taxodium, Thujopsis, Xylosma, Zelkova, and palm trees all produce pollen during December.

(Source: Ogren, T.L., Allergy-Free Gardening: The revolutionary guide to healthy landscaping , 2000, pp.262-265)

Also check out Allergy Free Gardening website.

This article on Low-Allergy Gardens has some tips on allergy-friendly landscapes.

Season Winter
Date 2007-04-02
Link to this record only (permalink)


Keywords: Shade trees, Fast growing trees, Ornamental trees, Acer

PAL Question:

We are looking for a tree to plant in our backyard to provide some shade. We live in a location that gets lots of sun. We want something that will grow quickly, develop a canopy that we can walk under, will get approximately 20-30 feet tall, 15-20 feet wide, and not need a lot of water. Evergreen is probably out of the question. Any suggestions?

View Answer:

I think that your best bet may be a maple. Three maple species surfaced that meet your criteria of a quick growing, 20-30 feet tall tree with an equal or greater spread, that will do well in the sun.

--Acer circinatum, the vine maple (the only downside--this may be a bit shrubby for your landscape)
--Acer ginnala, the Amur maple
--Acer palmatum, the Japanese maple (you'll need to be choosy in order to find a cultivar that will reach 20-30 feet, but there are some that do. Additionally, A. palmatum will tolerate drier soils than A. circinatum.)

Sources:
The Pacific Northwest Gardener's Book of Lists , R. & J. McNeilan, 1997, p. 18, 27, 30.
Tree & Shrub Gardening for Washington and Oregon , A. Beck & M. Binetti, 2001, p. 244-249.
Trees & Shrubs for Northwest Gardens , J. A. Grant & C. L. Grant, 1990, p. 56-58.

Season All Season
Date 2006-05-23
Link to this record only (permalink)


Keywords: Dendrobium, Orchids

PAL Question:

I have a couple of Dendrobium orchids, and one other that I don't know the name of. Both the Dendrobium have lost all their leaves, and I'm worried that they will die if they are not repotted soon. There is white fuzzy mold growing in the potting mix (which is just bark) of at least one of them, and I researched a little online and found that it is a common kind of snow white fungus (that may not be the right name) that is common to orchids in general.

I'm worried about root rot, and I'm wondering what I can do to try to revive these two orchids back to blooming. I read that soaking the roots in hydrogen peroxide can often help kill the fungus and then repotting thereafter can possibly revive them. What would you suggest for a repotting mix, and do you have any tips on reviving orchids once that have lost all their leaves?

The roots seem to still be intact, and do not appear to be rotted, as far as I can tell. I'm also wondering about good types of greenhouses/shelters to keep them in, as well as heaters to keep them a little warmer in the house -- they seem to be having a harder time with the 60 degree temperatures that my apartment tends to be. Any advice you could give would be great!

View Answer:

Some Dendrobium are deciduous, so your plants are likely acting exactly as they should. However, now that they've lost their leaves, you should restrict watering them through the winter, watering them only enough to keep them from shriveling, until flower buds form. Then, resume watering again. The species of Dendrobium that are deciduous require night temps of 50-55 degrees F during the winter.

Dendrobium grow well in Osmunda fiber, a potting medium, or bark if they are carefully staked, though they shouldn't be re-potted or divided until new growth starts. Also, Dendrobium with 4 or 5 shoots will grow well in a 4-5 inch pot, so you don't necessarily need to increase the pot size when you do re-pot your plants.

If you cut back on the water you give your Dendrobium through the winter, you shouldn't have to worry about root rot/fungi, especially if you repot them when new growth appears.

The advice above is taken from Home Orchid Growing (by Rebecca T. Northen, 1990, pp. 209-212).

Orchid Growing Basics (by G. Schoser, 1993, pp.40-45) shows some ways you can create a good place for orchids inside your home. For Dendrobium, placing the plants in a window with southern exposure, a grow light that will give them 12 hours of light each day, and humidity (Schoser recommends standing the pots on upsidedown flower pots in a tray of water) seem to be the most important considerations.

The Miller Library has many, many books on orchid growing.

Also, you might want to investigate the Northwest Orchid Society.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


Keywords: Thamnocalamus, Fargesia, Borinda, Screens, Bamboo

PAL Question:

I would like to have some bamboo planted in my backyard for privacy. However, I am uncertain as to which species will work the best. The planting area will be about 8 feet by 2 feet near a wooden fence. The area does get some sun but is mostly shady. I am looking for bamboo that is fast growing but not invasive. I want it to grow upwardly fast (no more than 30 feet) but I don't want it to invade my neighbor's property on the other side of the fence. Could you recommend at least three different bamboo species that would work for this area?

View Answer:

In the December 2005 issue of Horticulture magazine, local author Val Easton recommends a number of different clumping bamboos. (You should choose clumping rather than running bamboo for your privacy screen, as they will not be likely to invade your neighbor's property.)

Here are three recommendations from her article:
Borinda macclureana - hardy to USDA Zone 7 part sun, 12 - 20 feet tall
Fargesia robusta - hardy to USDA Zone 6, dense erect to 16 feet
Thamnocalamus tessellatus - hardy to USDA Zone 7 upright to 16 feet

You might try the following two nurseries for availability: the Bamboo Garden Nursery and Beauty and the Bamboo.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


Keywords: Continuing education, Potted plants, Container gardening

PAL Question:

I am going to create container plantings for some customers, and I wonder if you know the best source (book) for combining plants in containers. Also, where might I take a class in container planting?

View Answer:

The Miller Library has a large number of books in its online catalog on container planting, but here are a few which may be helpful to you:

Container Gardens by Number by Bob Purnell (Reader's Digest, 2004)
Contain Yourself by Kerstin Ouellet (Ball Publishing, 2003)
The Complete Book of Container Gardening edited by Alan Toogood (Quarto Publishing, 1991)
The Book of Container Gardening by Malcolm Hillier (Simon & Schuster, 1991)
A Practical Step-by-Step Guide to Complete Container Gardening compiled by Ideas into Print (Whitecap Books, 1997)

This booklist will give you an idea of the selection of books on the topic.

The Center for Urban Horticulture occasionally offers classes on container planting, as does Seattle Tilth.

Also, some local nurseries occasionally offer classes. One example is Swanson's Nursery.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


Keywords: Chaenomeles, Bonsai

PAL Question:

I was given a 40-year-old Quince bonsai tree and I would like to get some advice on taking care of it. I have a great book called, Bonsai Basics which has given me some insight as to how to take care of it, but I am looking for more information. I was also wondering about getting the tree repotted and the roots trimmed (which needs to happen very soon, as far as I can gather.) The roots have not been trimmed on this particular tree for about 3 years, and it has survived a pretty hard hit of insect and fungus pests.

View Answer:

The Puget Sound Bonsai Association has a website with useful information and links to other bonsai-related organizations and information. This is an active group with regular meetings, some lectures/workshops, and a good newsletter.

Nurseries such as Bonsai Northwest, a specialty nursery in South Seattle, often offer classes on bonsai care.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


Keywords: Pruning, Clematis

PAL Question:

There is a very large evergreen clematis starting to devour my detached garage. How far back can I cut this and when should I prune it back? It's one of the first early spring bloomers with white flowers, possibly armandii? But I am uncertain...I need help since I don't want to butcher it and lose it, but it needs a big haircut!

View Answer:

Clematis armandii does have the reputation for taking over the world. According to the American Horticultural Society's Practical Guide on clematis (Clematis, by Charles Chesshire, 1999), you can prune it AFTER is has finished flowering, which in Seattle, it normally does by the end of March. While this type of clematis can be pruned in late winter, it flowers on the previous year's wood, so pruning at that time may remove buds and prevent flowering that spring.

Step 1 - remove any dead, dying, damaged, or deranged shoots.
Step 2 - they suggest that no real pruning is necessary but you can cut it back to control its growth. But you do NOT want to cut it all the way back into old dark, woody growth. Prune directly above a pair of strong side shoots.
Step 3 - you will need to keep after it each year to avoid a build up of tangled growth.

Fine Gardening has an article by Lee Reich on pruning clematis here.

Season Spring
Date 2007-12-13
Link to this record only (permalink)


Keywords: Transplanting, Rhododendron

PAL Question:

Some friends of mine just bought an old house with a huge rhododendron up against the house. It is at least 8 feet high and probably 10 feet wide. I did not dig around and there may be multiple shrubs growing next to each other. What are the chances of moving the rhody successfully? Should it be cut way back before hand? Any particular time of year for moving it?

View Answer:

Fortunately, rhododendrons are very likely to succeed in being transplanted. Most experts recommend fall as the best time to transplant. Spring or late winter is second best.

The real challenge is getting a large enough rootball. A five-to-six foot plant requires a rootball of about 3 feet in diameter.

Step 1- dig a 12-18 inches deep trench around the rootball.
Step 2 - under cut the rootball to sever the roots from the underlying soil. The most important roots are the small feeder roots, not the big old ones. You can use a steel cable with a tractor or you can use a shovel and digging iron and a lot of hard work. The rootball will probably be about 8 - 12 inches deep and 3 feet in diameter.
Step 3 - tilt it on its side and slide a piece of 1/2-inch plywood under the rootball and set the plant upright. Use the plywood to move the plant to its new location. (A tarp works, too, if you can get it underneath the rootball.)
Step 4 - dig a new hole 4 feet in diameter and deep enough so that the rootball is 1 inch higher than the depth of the hole. (Slightly above grade)
Step 5 - water well and mulch around the perimeter of the plant BUT keep the mulch at least 2 inch away from the trunk of the plant.

Newly transplanted plants need some tender care and especially need to be watered regularly, but not over watered.

There were no recommendations to cut the foliage back. But it is always ok to prune out dead, dying, diseased or deranged stems. This also means you can prune out twiggy growth.

This information comes from Success with Rhododendrons and Azaleas by H. Edward Reiley (1992).

Season Fall
Date 2006-02-16
Link to this record only (permalink)


Keywords: Aleuria, Fungi

PAL Question:

I have several beautiful orange fungi growing in my two year old garden. They appear mostly between stepping stones (full sun) which have a deep underlay of gravel and sand, and also in a nearby bed which is semi-shady. Is this an indicator of an extreme soil condition that I should remedy? Where can I learn more?

View Answer:

Most likely, this mushroom is Aleuria aurantia, orange peel fungus or golden fairy cup. This species is widespread and common, often growing along roads or paths. It fruits from late fall to early spring.

It doesn't seem to be a problem for gardens....I would enjoy it as an added bit of fall color when it pops up in your garden.

Here is a link to a website in California with a nice picture and some information.

Season Winter
Date 2007-12-13
Link to this record only (permalink)


Keywords: Native plants--Washington, Natural landscaping, Native plant gardening

PAL Question:

I'm looking for a good publication on plant communities for my area, Whatcom County in northwest Washington. We want to encourage plant communities that will do well here, and have about 5 acres to work with. Can you make a suggestion, please?

View Answer:

If you are interested in plants native to Washington, I recommend these two books:

Kruckeberg, Arthur R., Gardening with Native Plants of the Pacific Northwest, University of Washington Press, Seattle, 2nd edition, 1996.
Pettinger, April, and Brenda Costano, Native Plants in the Coastal Garden - A Guide for Gardeners in the Pacific Northwest , Timber Press, Portland, OR, revised edition, 2002.

The Washington Native Plant Society is also a good resource.

If you are interested in plants that will grow well in your area, but are not necessarily native to Washington State, please check out the Miller Library's booklist about gardening in the Pacific Northwest.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


Keywords: Shade-tolerant plants, Epimedium

PAL Question:

Can you recommend some Epimedium species and tell me what kind of conditions they prefer?

View Answer:

The resources I consulted say that most Epimedium prefer part shade, and most are evergreen. Some will tolerate a partly sunny site as long as the soil does not dry out.

Epimedium perralderianum has bronze leaves that turn green and last throughout the year. It blooms in March/April. Epimedium x rubrum prefers shade, so if your site is partly sunny, this might not be the ideal choice.

Collectors Nursery in Battleground, WA, also carries several varieties.

One gardening website, Paghat's Garden, has especially good information. The site developer recommends in particular the following varieties:
Epimedium x versicolor 'Sulphureum', or Yellow Epimedium - for its evergreen foliage
Epimedium grandiflorum 'Lilafee' - for quite striking lavender flowers and evergreen foliage

Richie Steffen, curator of the Elisabeth C. Miller Garden, is the author of "The Ten Best Epimedium You Can Buy," published in the Northwest Horticultural Society newsletter, Spring 2011.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


Keywords: Insect pests--Control, Wildlife pests, Moles

PAL Question:

I live in Seattle and have, for the first time this fall, noticed dirt mounds on my property. These mounds tend to be located near patios/driveways, and are not in the sod. They are loamy, with no apparent holes, and are about three to five inches high. I wouldn't call them conical. There are no mole tunnels, and, as far as I can see, no bugs. The mounds are bigger than the little fine-grain mounds I have noticed in years past with small black ants crawling in them. Is there someone I can ask about what is causing these mounds, and if it is something to be concerned about? Could it be ants or mice?

View Answer:

From your description of the dirt mounds, it sounds as though the critter in your yard may be either a mole or a gopher. The easiest way to tell the difference is by the type of mound you have. Here is information on moles and pocket gophers from Washington Department of Fish and Wildlife's Living with Wildlife website.

Below is additional information from "Of Bugs and Blights" (in Balls and Burlaps, February 1988, pp. 4 and 14):

A gopher mound fans out from a hole near one edge of the mound. This hole remains plugged while the gopher is on the runway system. The gopher mound is relatively flat compared to the mole mound. Gopher mounds vary from 1 to 3 feet in diameter...several mounds often will be found together. They are not regularly found in a line as are mole mounds. The mole mound is somewhat conical and not much over a foot in diameter. The hole is not evident when you look at the mound. Push the soil aside and you will find it under the center of the mound. Each mound is connected with the other in a line by the moles' runway system.

According to the article quoted above, moles are more likely to be found in gardens in Western Washington than are gophers. We have the journal Balls and Burlaps in the Miller Library. The article discusses the problems and benefits of moles, as well as control methods.

I also consulted the Western Garden Problem Solver (Sunset Books, 1998) to see if I could identify your mound-maker. Ground squirrels leave their burrows open, so if your mounds show no opening, you probably don't have squirrels. Mole mounds appear volcano-like, with signs of soil excavation.

Here is a link to information on ants and their nests which you might look at to see if the images resemble the mounds of soil you are seeing.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


Keywords: Paulownia tomentosa, Woody plant propagation, Invasive plants

PAL Question:

How can I propagate a Paulownia tree?

View Answer:

Something to consider before propagating this tree is its invasive potential. Depending on your location, increasing the population of Paulownia trees may not be wise. The Plant Conservation Alliance includes Paulownia tomentosa on their "Least Wanted" list. If you are in King County in Washington State, you may be interested to know that the Center for Invasive Species shows this tree in its Early Detection and Distribution map.

Nevertheless, directions for propagation are available. Peter Thompson's book, Creative Propagation (2nd edition, Timber Press, 2005), states that Paulownia is best propagated by seed in the spring, or by semi-mature root cuttings laid horizontally just below the surface of the soil. I suggest that you think twice before propagating this tree.

Season All Season
Date 2007-12-13
Link to this record only (permalink)


1   |   2   |   3   |   4   |   5   |   6   |   7   |   8   |   9      »      [40]

 

Didn't find an answer to your question? Ask us directly!

Browse keywords or Search Again:

We are continually adding new questions, so be sure to keep coming back.

June 24 2013 12:55:25