Delphiniums reward the brave
Delphiniums are perfection, in my book. I mean, just look at that tower of flowers on one tall (4- to 7-foot) spire.
Sadly, the first flush of flowers is almost gone now. But follow my advice, and you'll get one more burst of beauty this year and learn how to make cut delphiniums last longer, to boot.
To get that second (albeit, smaller) bloom, you've got to bite your lower lip to prevent visible quivering. Then cut the stalks hard. If you cut the stems 8 to 12 inches from the ground now, the plant will push up more flowers by summer's end.
Growing delphiniums is not for the faint of heart. Garden author Tracy DiSabato-Aust says, 'Delphiniums are not cold-, wet- or heat-hardy; they are subject to a long list of disease and insect problems; they need to be staked, thinned, deadheaded and cut back for best performance; and they require summer fertilizer to maintain any vigor.'
Perhaps delphiniums should come with a manufacturer's warranty: 'This plant will get tall and needs support at all times. This plant may need plant food. This plant may be eaten to death by bugs or slugs. This plant may get hot and wilt if not watered. The lower leaves of this plant may get powdery mildew and fall off, leaving the plant looking marvelous from the knees up and ugly as sin from the knees down.'
Yes, delphiniums have issues. No warning can dissuade devotees, however.
I've never seen a more gorgeous mass of delphiniums than in Old Germantown Gardens, the private Northwest Portland sanctuary of Bruce Wakefield and Jerry Grossnickle. They have hundreds of delphiniums growing in an enormous stand that takes center stage in their garden. The stalks are as thick as sugar cane.
Even so, this plant tortures poor Wakefield.
'I have a soft spot in my heart for delphiniums,' he says, 'despite my cursing them as they're crashing to the ground in a strong wind or heavy rain. I do whatever I can to save them, they're so elegant.'
Just as he threatens to cry uncle, Wakefield stands tall against his delphiniums and reminds himself: 'You're bigger than it is. You're the one with the shovel.'
Wakefield grows several varieties of the perennial and suggests we try hybrids developed in Germany by Karl Foerster to be rugged and more vigorous. The difference is striking in Wakefield's garden; he bends down to show how the stems are sturdier and they need less stalking.
I'm a believer. Wakefield's 7-foot-tall spires stand straight, often without staking, while the other delphiniums, just steps away, require dozens of sturdy supports. For these, Wakefield uses tall bamboo poles next to each spire and secures the flower stem to it.
He says the real secret to growing gorgeous delphiniums is lots of water and tons of mulch. He lays 3 inches of new mulch on the beds each year. That's it no more fertilizer.
Here's another tip: slug bait. Don't be a Pollyanna and believe your delphiniums won't require a couple of applications of slug bait and something to lean on. Get out there and show 'em some support.
One more trick you might like to try. Delphiniums make wonderful cut flowers. Unfortunately, they don't last if you merely stick the stem in a vase. Try this old florist's trick to keep the flowers from wilting instantly: When you cut the stem, you'll notice it's hollow inside. Using a water bottle or pitcher, fill the stem with clean, cool water until it bubbles out. Then plug the end of the delphinium stalk with a piece of cotton ball. Your cut flower will last twice as long.
This week's to-do list
• Time to cut back stems of foxglove, spiderwort and coreopsis.
• Prevent corn earworm damage by putting a couple of drops of mineral oil in the silk at the tip.
• Want to play 'diagnose that disease' on your favorite plant that's looking peaked? Try the Plant Disease Control Web site from the Oregon State University Extension Service (plant-disease.orst.edu). It's awesome!
'Your Northwest Garden with Anne Jaeger' airs at 7 p.m. Saturday on KGW (8). Contact Jaeger via her Web site at www.gardengal.tv.