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Plant Answer Line Question

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

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.


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)

Date 2017-05-25
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Plant Answer Line Question

Keywords: Malus, Trees--Diseases and pests--Washington

My Fuji tree is infected with Cherry Bark Tortrix. Can the branches, leaves, and bark be used as mulch? What should be done with the wood? Can it be stored, and burned in our fireplace?


The leaves and branches can be mulched. The wood can be used, but it is a good idea to strip the logs of the bark and store the wood barkless. Removing the bark will destroy most of the caterpillars in the process. The wood is easier to chop when the bark has been removed, too! If you cannot remove the bark, use a mallet to tap the bark where ever you see galleries. This will most likely squash the caterpillars that are still in the wood.

Date 2017-12-08
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Plant Answer Line Question

Keywords: Plant care, Malus, Plant diseases

I am looking for a Malus (crabapple), not necessarily native, but is decorative in terms of blooms and foliage. I am also interested in plant diseases. I am hoping for a tree that will mature to about 20 feet with a 20 foot spread. Growing conditions are half shade, half sun, behind a semi-dense fence. We live in the San Juan Islands where the soil is not great and the tree will not get much water past establishment.


Here is what I found about the culture of flowering crabapples from the book Flowering Crabapples, the Genus Malus, by Fr. John L. Fiala (1994), p. 45:

"Crabapple trees luxuriate in full sunlight in deep rich soils that are well drained. Soils with a pH range of 5.0 to 7.5 suit crabapples well, but the ideal pH range is from 5.5 to 6.5. Even if gardeners are fortunate to have ideal soil conditions, they may not be able to allocate the best part of the garden to crabapples. Flowering crabapples, however, are not greedy and will accept almost any soil that is not waterlogged or overly dry. As long as the soil has a reasonable amount of nutrients and water, crabapples manage to do very well.

"Like most plants, crabapples prefer rich sandy loams, but even in heavier clay soils they do better than many other trees and shrubs and seem to bloom well once they are established. They will accept slightly wetter soils than lilacs, for example, but in these heavier soils they should have excellent drainage as they will not grow in waterlogged, swampy areas nor in soils inundated for long periods of time."

Regarding particular trees you might like that would be disease-free, I found a couple of crabapples that were listed in The Pacific Northwest Gardener's Book of Lists,by Ray and Jan McNeilan (1997). This is from page 24:

1. Malus 'Prairiefire' has red foliage when young that matures to deep green, has bright pink/red blossoms and deep purple-red fruit. It grows to 20 ft x 20 ft and has excellent resistance to scab and mildew (Pacific NW scourges).

2. From the book Flowering Crabapples, the Genus Malus, by Fr. John L. Fiala (1994), p. 147: Malus sieboldii 'Calocarpa' (trade name, Redbud crabapple) is a dense, upright to spreading tree, 15 ft high and as wide... buds deep red, opening to single, white to pink-white flowers 1.4 in across; fruit 0.4 in diameter, bright red to red-orange... A reliable, abundant, annual bloomer... One of the most beautiful of all the ornamental crabapples both in bloom and in fruit. Birds relish the small fruit which never is messy.
From The Pacific Northwest Gardener's Book of Lists, p. 25, I found that this tree is rated 'excellent' in terms of resistance to both mildew and scab.

3. Malus 'Strawberry Parfait' is a "vase-shaped, spreading tree 18 ft high and 20 ft wide; leaves red-purple, turning green with maturity; buds red, opening to single, pink flowers in clusters; fruit yellow with red blush, 0.4 inch in diameter. Excellent disease rating but not rated for fire blight [bacterial disease]. Not very ornamental."
From The Pacific Northwest Gardener's Book of Lists, p. 25, I found that this tree is rated 'excellent' in terms of resistance to both mildew and scab.

[Note: fire blight appears to be more the issue in the midwest and eastern U.S.]

Date 2017-12-09
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Plant Answer Line Question

Keywords: Pyrus, Malus, Tree identification, Prunus

Is it possible that I'm seeing cherry trees flowering this early (mid-February)? Some have white flowers, and some are pink.


It is certainly true that things are flowering early due to our mild winter this year. Last year, the famous cherry blossoms in the University of Washington's Quad began opening on March 13, and this winter has been warmer, so they may be opening earlier than that. While it is possible you are seeing flowering ornamental cherries (Prunus species), they are easily confused with their cousins in the same genus, flowering ornamental plums-- extremely common street trees in Seattle--most of which are definitely flowering now. Ornamental pears (Pyrus) are also flowering now. They have white petals, and might be mistaken for cherry trees as well but the distinctive odor of pear blossoms is a big clue to their true identity: acrid, astringent, and just plain stinky!

The Vancouver Cherry Blossom Festival offers some pointers on how to tell the difference between cherry and plum blossoms. Most cherry blossoms are not noticeably fragrant, while plums are. Cherry blossoms usually have small splits or indentations at the ends of their petals. Note, however, that the book Japanese Flowering Cherries by Wybe Kuitert (Timber Press, 1999) says cherry "petals are mostly [emphasis mine] retuse," that is, not all of them have a shallow notch or split on the ends of the petals.

Project BudBurst, a citizen-science phenology project, has information on identifying cherry trees. There is also a guide to telling the difference between cherry and apple blossoms (apple blossoms have 3 to 5 styles whereas cherries have one). According to the British Natural History Museum, one unifying characteristic of cherries is "flowers in clusters with stalks all arising from a central point, or arranged along a short stem, or in spikes."

Date 2017-05-12
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May 23 2018 14:32:42