Lusty for Lavender
Marvelous, Hardy Plants Do Well in the Northwest
By Rachel Foster 5/13/04

Anyone with a sunny garden who is looking to reduce water use should be thinking lavender: not just one token plant, but lots of it. This fragrant marvel from lands around the Mediterranean needs little care, tolerates poor soil, and is more cold-hardy than that provenance might suggest. Rocky or sandy conditions may be ideal for lavender, but it is remarkably adaptable to ordinary garden soils, even in soggy Northwest winters. Its only real requirement for a long life is decent drainage.
At the Sawmill Ballroom Lavender Farm on Hamm Road, Joey and Nancy Connolly Blum claim to have heavy, clay soil: Planting on sloping ground provides the drainage the plants need. A thick mulch of sawdust conserves moisture. "We used to make a big deal out of telling our customers we never water our plants," said Joey when I visited last summer. "After this very dry year, we may have to say we seldom water our plants." Established lavender doesn't need irrigation to survive, he said, but the plants will look fuller with adequate moisture, and the quality of the flowers improves.
In small spaces, multiple lavender plants look great laid out in severely geometric designs. Alternatively, you can mix it with other drought tolerant plants for a more informal effect. Lavender's tolerance for dry soil makes it a good container plant for water-wise gardeners. The drought tolerance of plants in containers won't equal that in the open garden, but waiting a few days for water shouldn't hurt. (Potted lavender can go in a frost-free but unheated garage for the winter.)
While any lavender variety can be grown in a pot, my personal favorite is Spanish lavender (Lavandula stoechas). The jaunty wings at the tip of every inflorescence add color and character, and there are several flushes of bloom throughout the summer. L. stoechas is not as hardy as other popular varieties, although many specimens have lived through several recent winters. A typical purple flowered variety is 'Otto Quast.' In 'Leucantha' the flowers and showy bracts are white with green veins.
Joey and Nancy Blum grow and sell about 65 lavender varieties, both old and new. Their farm is a great place to compare flower and leaf color, plant size and blooming time. Gray-leafed 'Tuscan,' their own introduction from a farm in Italy, is a variety of English lavender (Lavandula angustifolia). Others are 'Twickel Purple' and a compact old favorite named 'Munstead.' Early blooming and hardy, it's about one- third the size of most its neighbors at the farm. Nancy says, "It has a lovely, soft fragrance without sharpness."
English lavender self-sows, but many popular lavenders are sterile hybrids. Crosses between Lavandula angustifolia and L. latifolia, they are grouped under the name L. x intermedia (books sometimes refer to them as lavandins). 'Provence' and the fat-flowered 'Grosso' belong in this group. The hybrids tend to bloom a bit later, and foliage color is variable, from green to gray. Lavandula latifolia 'Silver Frost' has foliage of the brightest silver, standing out like a beacon in mixed beds at the Lavender Farm. If you are planting lavender in masses, you can choose two or more foliage colors to make a pattern.
In nature, old lavender grows irregular and leggy, with the thick, gnarled stems exposed. Most gardeners prefer the neat bun shape associated with young plants. Provided they get a full eight hours of sun a day, a regular annual clip after flowering can keep plants that way for years. It's good for hedges, or anywhere plants need to be uniform. Nancy recommends clipping in July or August. Alternatively, you can shear the plants when growth begins in spring. Or you can prune individual branches for a more natural look, leaving about one quarter of last year's growth.
Healthy plants in ideal conditions can be cut back hard, even into old wood if you can see buds there, but this should be done only in spring. Nancy recommends doing it right around Mothers Day. "Some varieties push new growth right from the bottom," she says. "By late spring, if you can see that new bun of leaves, cut back to it."
Here is another tip from Nancy: If you are not in production, don't rush to harvest your lavender. Insects, bees in particular, just love it, and the plants are constantly in motion from dawn to dusk. Nancy suspects some bees sleep right in the plants! Bees continue to work the plants long after the strongest flush of blue is gone, and she's learned that even the dried-out stalks are full of fragrant oil. She crushed a brown head in her fingers to show me the shiny black oval seed; even with the seed already ripe, the old flowers were still intensely fragrant. So you and the bees can enjoy your lavender for a long time and still cut fragrant stems.