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.

effectiveness of neem oil and horticultural oils

We’ve got an established grapevine that has acquired erineum mites, and a horticulturist advised us to use dormant spray this fall. The dormant sprays are rather nasty things, and I recently ran across Neem oil, which says it acts as a miticide. It sounds like the concentrated Neem oil is pretty nasty, too, but I’m wondering: (1) will Neem oil work to get rid of the mites; and (2) is it any less harmful to the environment than the traditional dormant sprays?

According to the University of California, Davis Integrated Pest Management program, Erineum mites will not adversely affect your grape crop, they merely cause an aesthetic problem (disfigured leaves).

Washington State University Extension does mention using dormant-season horticultural oils or wettable sulfur. Excerpt:

“The grape erineum mite, Collomerus vitus, is actually a type of eriophyid mite. They are very tiny, whitish, worm-like, and spindle-shaped. Their bodies have definite annulations or rings, and only two pairs of legs directly behind the mouthparts. They overwinter under outer bud scales and feed on leaves during summer. The upper leaf surface
becomes blistered, and blisters on the lower leaf surface turn white, yellow, or brown. Colonies of mites live inside the blisters (erinea) formed by their feeding on the lower surfaces. The blisters contain masses of enlarged leaf hairs. Large infestations can cause major stress on young vines. From mid-August to leaf drop, the mites migrate back to the overwintering sites beneath bud scales.

“Apply according to label instructions. Dormant-season horticultural oils or wettable sulfur applications may be helpful.”

I have only seen references to serious damage from this pest when the grapevine affected is very young, so you may be able to do nothing at all. Neem’s effectiveness as a miticide is as yet unproven, and when selecting a Neem-based product, you have to make sure it actually contains the active ingredient said to affect insects, Azadirachtin–some “Neem” products do not. (Also, Azadirachtin affects good bugs as well as the ones you may be trying to control, so it is definitely not risk-free).

Paghat’s Garden website article on the “Myth and Reality of Neem Worship”

Although most horticultural oils are petroleum-based, there are supposedly a few out there which are being made with vegetable oil, which would be a preferable alternative if you really needed to spray for the erineum mites. Colorado State University Extension has an article on dormant oil.

conditions for growing fig trees

I purchased a fig tree and my property has very limited space. There is an ideal strip of land by the south side of the wall that gets plenty of sun. I read that fig trees should be planted near a south facing wall, but my only concern is how close can it be to the side of the house. The strip of land is only about 2 feet wide and I also read that fig roots are shallow and spread beyond the canopy. I’m worried that the root system would cause damage to the foundation/basement.

The roots of a fig tree may be shallow, but they may spread out as much as 50 feet, and if the soil conditions are right (soft, permeable), roots may go as much as 20 feet deep. I think planting so close to the house is not ideal,
unless you were to have a dwarf variety of fig in a container (such as Petite Negri or Negronne). If there are any cracks in your foundation, then tree roots may be a concern. Tree roots do not usually penetrate a solid wall, although as they grow and expand, they can exert pressure on surfaces. The other concern with planting that close is that you will find you frequently need to prune branches away from the house. There is a tradition of growing fig trees as espalier forms (trained to grow flat, on one plane), but to do this you need to restrict the tree’s roots in a container. Below are links to information on how to do espalier:

Royal Horticultural Society

The following links have excellent general information about growing fig trees:

Purdue University Extension

California Rare Fruit Growers

Here is information from Reads Nursery, a British fruit specialist.
Excerpt:

Allow 8′ – 15′ horizontally and 6′ – 10′ in height per plant. Root restriction is required. Construct a box of 2′ square paving slabs 4′ x 2′ against a wall or side of greenhouse, leaving 3 inches showing above ground. Put 9 inches of rammed brick rubble in the bottom and fill up with good soil such as John Innes No 3. [*This is a British product–you can use compost instead.] When planting loosen root ball carefully around the outside and plant 1-2″deeper than before. Water in well. Pruning. Treat as for Figs in Pots but, on a wall, the plant should be fan trained on horizontal wires 12 inches apart.

on dividing Gunneras

When and how do I divide my Gunnera?

“Divide large types before growth starts into single crowns in midspring.” (Source: American Horticultural Society Plant Propagation, ed. by A. Toogood, 1999, p. 198)

“Many gunneras are huge and so are impossible to dig up and divide in the conventional sense. For propagation, cut pieces from the edge of the clump. Pot up in a large pot and in a fibrous medium and keep moist.” (Source: The Complete Book of Plant Propagation, ed. by C. Heuser, 1997, p. 40)

The sources I looked at indicate that you should divide your Gunnera in April or May. Because of the size of the plant, it may be impractical to divide the rootball. You can use a spade or pitchfork to cut sections from the main clump, and then plant those divisions in pots, keeping them moist. Gunnera is a tough plant, and should take well to this kind of division, as long as there is adequate moisture.

Should you need to protect your Gunnera over the winter months, you can cut the leaves and use them like a tent to protect the crown of the plant during the coldest months.

edibility of Mahonia species

Are the fruits of Mahonia x media ‘Charity’ edible, similar to Mahonia x media?

First, an aside: Mahonia has been ‘moved’ to Berberis, so that now Mahonia x media is named Berberis x hortensis, and Mahonia aquifolium is now Berberis aquifolium. Since the resources I will be quoting use the former names, I will leave them as they are.

Here’s what British author Alys Fowler says in her book, The Thrifty Forager (Kyle Books, 2011):

“All Mahonia species are edible, long-used for jams and juices in their native homes […] Sometimes you’ll find Mahonia nervosa, the Oregon grape, with the roundest grape-like berries. It looks very like Mahonia aquifolium but usually fruits later, around early autumn. […] Even when fully ripe, the acidic berries [of all Mahonia species] are too bitter to eat raw–they should be cooked into pies, jellies and jams. The flowers are edible, but bitter. The fruit needs to be picked and processed into jam or jelly very quickly, and it stains everything. It’s very low in pectin, so either add crab apples or add liquid pectin, following the usual jam making rules. You can also make an Oregon grape cordial which tastes a bit like blackcurrant cordial. Because of the low sugar content, it will need to be frozen if you want to store it–it’s a very sharp cordial, I use 350-400g (just under 1 lb) if granulated sugar to 600 ml (1 pint) of fruit. If that’s still too sharp, try mixing it with concentrated apple juice to sweeten it.”

Plants for a Future Database has pages for several Mahonia and Berberis species, including Mahonia x media, and its fruit is listed as edible.