The weeping crab apple Malus 'Red Jade' in full, mid-April flower, overhanging the pond in the author's back garden.

IT TOOK my husband and me most of one summer to dig the pond in our back garden, so you can imagine I had to find just the right tree to be reflected in it. The next spring I paid special attention to the parade of bloom as one kind of ornamental tree after another unfurled its flowers. While the cherry's blowsy pink flower puffs are excitingly showy, I decided it was the open white flowers of the crab apple that would look best in my naturalistic garden.

I love that crab apples' blooms are shown off against the chartreuse of the new leaves, which come on quite early in March. (Many spring-flowering trees bloom on bare wood, with the foliage following.) Add sweet fragrance, hot pink balls of bud opening to snow white flowers, plus bright autumn berries to please the eye and the birds, and it seemed clear that a crab apple should overhang the new pond. But which one?

Local tree expert Arthur Lee Jacobson says there are more than a hundred kinds of crab apples in commerce, and warns that "some have no business being for sale."

While I'm afraid that I look first at tree shape and flower, the most important consideration in picking a crab apple should be disease resistance. In cool, moist climates like ours, crabs are notoriously subject to scab infection.

The tree I ended up planting, Malus `Red Jade,' which seven years ago was on the recommended lists, now shows up on "to avoid" lists. I've had few problems with it, and its foliage stays fairly healthy into fall. However, if I were searching for a tree today I'd pay attention to current recommendations, and find a different small weeper with white flowers, such as `Sinai Fire,' now considered to be the best white-flowered weeper.

Now In Bloom Drumstick primroses (Primula denticulata) grow to 18 inches tall and have balls of tiny, yellow-eyed flowers held above the foliage. They like moist soil and look their best growing along the shores of a pond or stream. 'Rubra' has red-purple flowers; var. 'Alba' is snowy white.

Crab apples are reliably hardy, bloom for several weeks with flowers ranging from pure white through pink and purple, are not too fussy about soil, and come in a variety of shapes and sizes. They need good drainage and irrigation during droughty periods. And remember, these are not orchard apple trees to be pruned hard for fruit production. They require only a gentle thinning to show off their own graceful lines.

How to find the cultivars that perform best in our climate? Jacobson says responsible local nurseries carry only the relatively scab-resistant kinds. He warns that all too often the crab apples with the most glorious flowers follow them with the most disfiguring scab (which ruins the look of the leaves but usually doesn't hurt the tree's health).

He appreciates crabs for their fruit rather than flower, particularly admiring M. `Red Jewel,' with cherry-red fruit that persists until the spring foliage unfurls; `Professor Sprenger' for its "nearly walnut size and cheerful-looking" orange-red fruit; and the showy fruit of `Golden Hornet.'

We have a Western native crab apple, Malus fusca, which makes up for what it lacks in showiness (small pink flowers and yellow or purplish-red fruit) by tolerating wet feet, thriving along streams or in boggy areas. To see a magnificent specimen of Malus fusca in the Washington Park Arboretum, cross the street by the Graham Visitors Center, walk about 150 feet due west along the trail to the Winter Garden, and you'll find one of the largest native crab apples in Seattle.

For a list of disease-resistant crabs, call the Washington State University Extension Service office at 206-205-3100 and ask for their publication "Crab Apples for Western Washington Landscapes" (EB1809).

Advance Notice

The Master Gardener's Plant Sale and Garden Fair is as much an event for learning about plants as buying them - although there will be plenty of annuals, perennials, natives, fruits, vegetables and herbs for sale. Times are Saturday, April 21, 9 a.m.-4 p.m., and Sunday, April 22, 10 a.m.-3 p.m., at the Center for Urban Horticulture, 3501 N.E. 41st St., Seattle. Information: 206-296-3425, tape number 118.

Valerie Easton, a horticultural librarian who writes about plants and gardens for Pacific Northwest magazine, is the co-author of "Artists in Their Gardens" from Sasquatch Books. Her e-mail address is vjeaston@aol.com.