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Alaska Life

Tips for dealing with delphiniums

  • Author: Jeff Lowenfels
  • Updated: September 29, 2016
  • Published July 25, 2012

If ever there were a plant that does well in our climate, it's the delphinium. It doesn't matter if it is sunny or rainy; Alaska gardens always grow the very best delphiniums. Their tall spires are in bud and bloom this week all over Southcentral. If you don't have them, just walk around the block and I am sure you will be able to enjoy some planted by neighbors.

There are a few things you need to know, however, if you are new to delphiniums. They are sold as starts locally and while fall is the time Outside gardeners are advised to plant them, this columnist thinks anytime is ideal. In fact, if you see any for sale now, grab them. You can believe me and dip them in some mycorrhizal and plant them right away (assuming they have been hardened off) or you can believe Them -- the Lower 48 folks -- and just keep them watered and plant them in the fall.

Either way, these are plants that need soils with lots of organics. This is important to feed them, but also because organics-filled soils retain water and delphiniums do best if the soil they are grown in never dries out. Mulching with leaves will also help ensure the soil remains moist.

Delphinium plants tend to wind down over the years if they are not thinned out. They may not stop blooming, but the spires will get progressively shorter each year and the plants will seem stunted. Some gardeners thin them every year. Others literally divide clumps every three to five years instead.,

Alaskan delphiniums also have their own pest, the delphinium defoliator. This caterpillar attacks as soon as the first few leaves appear. Neem- or Bt-based products will get rid of them. Thrips are also a problem as they are attracted to white and blue, a popular delphinium color combo. Again, neem oil products seem to work. Blue sticky traps, too, would work, but probably need to go out before buds open. You can make your own with blue cardboard and light motor oil.

Some people have problems with slugs when they grow delphiniums. Slug baits are in order if you have problems, as is hand picking. When setting up your trapline, make sure to keep it outside the garden. Don't attract slugs into the garden!

A constant call in my weekly gardening calendar is to stake delphiniums. These need it more than anything else on your property, unless you are growing peonies or tomatoes. This is because delphiniums have a hollow stem and the massive surface area created by the multitude of flowers that catches rain which weighs down the plant causing the stem to snap. It's a sad sight. These hollow stems should be cut down to the crown of the plant after the first frost so they don't fill with water and rot the plant.

As a result of having a hollow stem, many a delphinium has been sabotaged by a bad staking job. Instead of tying the plant to a stake, make a cage for the plant so nothing touches the stem. It's best to do this early in the season and then make sure that all the plants are contained as they grow. It is also a good idea to try and not be too obvious. Use green yard tape, not red, and green supports, not tan ones. These are magnificent flowering spires you are displaying, not a caged animal.

You can start delphinium from seed. There are some fantastic colors, deep and light purples and blues, white, fringed and combos. The seeds are easy to start. They are not difficult. On the other hand, because they do so well, local nurseries carry mouthwatering selections.

Jeff Lowenfels is a member of the Garden Writers Hall of Fame. You can reach him at teamingwithmicrobes.com and hear him (and call in) on the Garden Party from 10 a.m.-noon on Saturdays on KBYR, 700 AM.

Garden calendar

Willow Garden Tour, Coyote Garden Tour: Saturday for both (call 495 6034 or 495-2080), Sunday for a second chance at Les Brake's Coyote Garden (495-6525). Meet on Saturday at the Willow Community Center at 9:45 a.m. for maps, etc. Bring lunch. Have fun. See some fantastic gardens.

SNAP AND OTHER PEAS: START EATING.

BEETS AND CARROTS: THIN EVEN MORE.

RASPBERRIES: SHOULD BE ALMOST READY. DON'T LET THEM GO TO WASTE.

BUTTER AND EGGS: THEY ARE UP, GROWING AND GETTING READY TO FLOWER. GET 'EM BEFORE THEY GET YOU. HAND PICK, HOE, ETC. NO POISONS.

HEARINGS TO SPRAY PESTICIDES: STATE AGENCIES SHOULD HAVE TO CONTINUE TO GO THROUGH A HEARING PROCESS BEFORE BEING ABLE TO SPRAY PESTICIDES AND HERBICIDES ON PUBLIC LANDS. THE GOVERNOR DOESN'T THINK SO. ALL ORGANIC GARDENERS NEED TO CONTACT DEC AND TELL THEM THIS IS A TERRIBLE IDEA. HTTP://DEC.ALASKA.GOV/

ALASKA BOTANICAL GARDEN: WEDNESDAY IS YOGA IN THE GARDEN. SEE ALASKABG.ORG FOR DETAILS.

Jeff Lowenfels

Gardening

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