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Elisabeth C. Miller Library

Archives: Plant Answer Line Q & A

Plant Answer Line questions and answers.

identifying Amaranth daisy from other daisies

I am doing some research on daisies. I have had trouble finding out what Amaranth daisy (Pearly Everlasting) looks like, and how to differentiate it from other daisies.

Pearly Everlasting is Anaphalis margaritacea, which is in the plant family Compositae (also called Asteraceae), according to David Mabberley’s The Plant-Book (Cambridge University Press, 1997). Below are links to images and information about this plant.

The problem with common names like ‘daisy’ is that they may refer to a large number of different plants. ‘Daisy’ can refer to Bellis perennis, Gerbera jamesonii, Olearia species, Chrysanthemum coronarium, Felicia bergeriana, Leucanthemum vulgare, and many other disparate plants.

Below are web links to sites which may help you with plant identification. There are also many good books on the subject, and an excellent starting place is Roger Phillips and Martin Rix’s The Botanical Garden (Firefly Books, 2002).

growing ornamental gourds

Can I grow ornamental gourds in the Seattle area? Do you know of anyone who has expertise in gourd crafts?

You should be able to grow ornamental gourds successfully here in Seattle. They are in the same family as pumpkins, squash, cucumbers, and other Cucurbits. Here is a link to Washington State University Extension’s resource on growing and curing gourds.

Here is an excerpt: “Ornamental gourds should be planted when all danger of frost is past. Gourds do best planted near something that will allow the vines to climb. Keeping the fruit off the ground helps prevent rot. Plant the seeds 1 to 2 inches deep, 12 to 24 inches apart in soil that contains plenty of compost, is well drained and receives lots of sunshine. Keep the plants moist.

“How much to fertilize the vines is a tightrope the grower walks. Too much and you have heavy vine growth and retardation of fruiting. Too little and you have weak vines and no fruit. The consensus appears to be working fertilizer into a ring around the hill when you plant your gourds and again 30 days later. The root system is shallow so care must be taken when weeding and fertilizing.

“Gourds are monoecious, that is they have separate male and female flowers on the same plant. The male flowers appear first, followed by female flowers. You can tell when the female flowers begin because there is a small gourd shape beneath the petals. The flowers are yellow in color and stay open for only one day. You can pollinate your flowers with a toothbrush to ensure fruiting.

“Gourds should be allowed to mature and dry on the vine. If they are not thoroughly ripened when picked, rot is a definite possibility. When cutting them, use sharp shears and leave a few inches of stem attached. Be careful not to break the skin when handling the gourd. Any cuts or bruises can become entry points for disease and rot. Frost will kill the vine but will not harm mature gourds.

“Wipe the fruit with rubbing alcohol, or dip it into a bath of one part bleach and nine parts water. Dry the gourd and leave it to cure in a dry, warm, airy room. The top of your refrigerator is an ideal spot. Turn them often and make sure that they do not touch one another. Check the gourds frequently and discard any that are beginning to rot. After the gourds have dried, you can polish them with a liquid wax.

“Use your gourds to decorate for fall. Place them in a bowl. Gather the stems together and hang them as a swag. Make a wreath. When the season is ended, they can be stored in a dark dry place for next year, or you can break your favorites open, harvest the seeds and start over again next spring.”

You may be able to find out about gourd craftspeople by visiting local farmers’ markets and asking vendors who sell gourds. You should also keep an eye out in the fall for crafts classes and workshops at local nurseries and places like Seattle Tilth. The American Gourd Society website includes an extensive list of crafting resources and techniques. You can also find a directory of gourd artists on the Washington State Gourd Society website.

ammonia odor in compost

What does it mean when newly purchased commercial compost smells strongly of ammonia? The compost I’m talking about is 2 yards worth and it has been delivered; I’m stuck with it. Will it improve or hurt the soil I intend to combine with it? And should plants get near it? This is serious. I have obtained all new plants and prepared everything for a new bed…but I’m not going ahead with this because of the amount we’re dealing with.

According to Ann Lovejoy’s October 16, 2003 column from the Seattle PI, a strong ammonia smell indicates “immature” compost that could harm plant roots.

Compost facilities sometimes have bad batches with too much nitrogen in the original mixture of clippings, compared to the amount of carbon, and it can be solved over time by adding “carbon-rich materials such as leaves or [finely ground] wood chips,” according to a compost odor factsheet produced by Resource Recycling Systems, Incorporated. Acidity can also be a factor–less acidic mixtures sometimes remain immature until more acidic ingredients (such as leaves or needles) are added.

If you haven’t already contacted the company, you might try that. At least one local company stands by its compost with a satisfaction guarantee, and that fact may encourage whoever sold you this compost to make things right for you.

effects of tobacco smoke on growing plants

We are installing a greenhouse (8×8 ft.) soon and there is some disagreement as to whether it is o.k. to smoke cigars inside. Is there definitive research on the effects of tobacco smoke and incidence of tobacco mosaic virus or other ill effects, other than the health ones, that is?

The effects of tobacco smoke on growing plants is the stuff of many science fair projects (like this example), most of which determine that the smoke stunts plant growth.

As for tobacco mosaic virus,University of Connecticut Integrated Pest Management has information on how to prevent this disease:

TMV is spread readily by touch. The virus can survive on clothing in bits of plant debris for about two years, and can easily enter a new plant from a brief contact with a worker’s contaminated hands or clothing. Tobacco products can carry the virus, and it can survive on the hands for hours after touching the tobacco product. Ensure that workers do not carry or use tobacco products near the plants, and wash well (with soap to kill the virus) after using tobacco products. Ensure that workers wear clothing not contaminated with tomato, tobacco or other host-plant material. Exclude non-essential people from greenhouses and growing areas.

University of California, Davis and Washington State University Extension concur with this information.

For general information on the toxins and irritants and added hazards of cigars in particular, see this information from the National Cancer Institute. It takes longer to smoke a cigar than a cigarette, so the duration of plant (and human) exposure to pollution is potentially longer as well.

Unless there is a compelling reason to smoke cigars in the greenhouse, I would avoid it, as it is not beneficial to the plants (or the smoker, of course) and more than likely will be detrimental.

keeping Magnolia blossoms fresh

Is there anyway to slow the browning of a fresh cut Magnolia flower? I am using it as a decoration and would like to cut it the day before.

According to The World of Magnolias by Dorothy Johnson Callaway (Timber Press, 1994), if you cut the flowers at an early stage (before they open) and keep them in a cool room, they will last for several days. They are naturally fragile, and it is for this reason that they are not usually used on a large scale by florists.

If you only need to keep the blossoms fresh for a day or two, then keeping them cool should be sufficient.

pruning laceleaf Japanese maples

How do I go about pruning my laceleaf Japanese maple, and when should I do it?

Cass Turnbull’s Guide to Pruning (Sasquatch Books, 2006) specifically addresses the pruning of laceleaf Japanese maple (Acer palmatum dissectum). To summarize, she advises combing out any dead leaves, and then thumb-pruning tiny dead twigs (light gray in color). Remove dead or dying branches, especially near the bottom and inside the tree, working from the bottom up and the inside out. She likes to do summer pruning on this type of maple, but early winter is also acceptable.

You can find additional information on pruning from the local organization Plant Amnesty , including an instructional video in which Plant Amnesty founder Cass Turnbull demonstrates how to prune a laceleaf Japanese maple.

information sources about mulching

Can you give me some good sources for information about mulching and different mulching materials?

Below are many links to information about mulch, including several from Pacific Northwest government agencies. Explore these sites for lots of other useful information about gardening! There are also many helpful books on the subject, such as Mulch It! by Stu Campbell (Storey Books, 2001) and the Brooklyn Botanic Garden’s guide, Healthy Soils for Sustainable Gardens edited by Niall Dunne (2009).

There is an excellent introductory article on the Brooklyn Botanical Garden website entitled “How to Use Mulch”.

ABOUT MULCH, types, and uses–Cornell Cooperative Extension (NY)

King County (Washington) Solid Waste Division mulch info
Make the mulch of it!

INFORMATION FROM THE PACIFIC NORTHWEST (generally useful)
—
Saving Water Partnership (Seattle)

—King Conservation District (Washington), manure share program

COMPOSTING COUNCIL OF CANADA:
Compost.org

using fluoridated water in the garden

Are there any adverse effects from using fluoridated water in the garden?

I do know that some indoor plants do better with water that is not fluoridated. There are conflicting opinions on the effects of fluoride on human health and the environment (including plants). According to this 2004 article entitled Water fluoridation and the environment by Howard Pollick in the International Journal of Occupational Health (reprinted by the Centers for Disease Control), the fluoride level in residential water (as opposed to industrial runoff) seldom rises above a level of concern for plants.

For an alternate viewpoint, see the Fluoride Action Network’s website.

the poisonous western yew

Is our native yew tree poisonous?

Taxus brevifolia, Pacific or Western yew, is native here. The Sunset Western Garden Book (2001, p.628) says that Taxus fruit, seeds, and foliage are poisonous if ingested.

Plants of the Pacific Northwest Coast by Pojar and Mackinnon (Lone Pine, 2004) says that “Western yew seeds are poisonous and humans should avoid the fleshy ‘berries,’ although a wide variety of birds consume them and disperse the seeds. The foliage is poisonous to horses and cattle.”

The Plants for a Future database has more information at this link.

composting coffee grounds

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?

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’ 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.