iGrow Gardening: Grow me, grow me!

Farm Forum

Gardeners are often looking for good solid perennials that will have nice flowers, be easy to take care of, grow nicely but not take over the garden. One group of plants that should be considered is the Veronicas. There are several species of this durable perennial and probably dozens of different cultivars to choose from. Most of them are hardy for our area withstanding our cold and often open winters yet they can also take the heat and drought of our summers. Flowers range in color from white to pink or blue-purple.

Veronicas offer the gardener a wide array of plants to work into many different landscaping niches in the garden. Some are prostrate, only raising their flowers a few inches above the ground while others can reach 4′ in height and make excellent cut flowers. Many work well in the rock garden while others are better suited to a moister location in the mixed border. Some are late spring blooming while others display their flowers for the rest of the summer and even up until frost. Deadheading will usually encourage additional flowers to develop, extending their period of bloom. Most Veronicas can be easily propagated by spring or fall division, stem cuttings during the summer or by seed, but vegetative means should be used when propagating cultivars as they will often not come true from seed. Even though they are easy to propagate from seed, they seldom self-seed and do not spread by rhizomes so they do not tend to take over the garden. However, the low-growing types will readily increase in size as the creeping stems grow over the ground; they look good draping over rocks or walls.

Veronica incana, or wooly speedwell has 3-6” long terminal spikes of blue flowers over a plant comprised of silvery-white leaves and stems. Plants grow about 12-15” tall and prefer a full sun location with very well drained soils. Like other hairy-leaved plants, excess moisture will cause leaf loss and wet winter weather may kill the plant. This species works well as an edging plant and is very attractive in bloom but looks great with its silver foliage all season long. There are a number of cultivars available including: ‘Glauca’ – more silvery foliage and deeper blue flowers; ‘Silver Carpet’ – purple flowers with silvery leaves; ‘Wendy’ – lavender-blue flowers.

There are some insecticides that can provide some control for the home gardener. There is an organic product called Bacillus thuringiensis var. san diego, often just called B.t. But you have to look for the formulation that is effective against beetles, not the ones that are available for controlling caterpillars or other insects. This is a stomach poison for the beetles and controls them after they eat foliage that has been treated with the B.t. It has to be applied repeatedly to maintain control.

Some other chemical options include insecticides that contain the active ingredient of Azadirachtin. Some trade names to look for include: Azatin XL Plus, BioNeem, Margosan-O, and Neemix. This chemical interferes with the molting process of the larvae. Another product to look for will contain Rotenone, an insecticide that has been around for a long time and it still appears to be effective against Colorado potato beetles, at least to the youngest larval stages. Once the larvae get to the 4th instar (after molting three times) they become much more difficult to control and the larvae cause much more damage.

Colorado potato beetles are one of the most troublesome garden pests because they feed on one of our favorite vegetables and they are so persistent and difficult to control. Try to use a variety of methods to control them and you will probably still get to harvest at least some potatoes unless the plants were badly defoliated after blooming. For additional information try these other online resources: and

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You can submit your gardening questions to the Ask-an-Expert section of the website in the “Gardens – Gardening.” There you will be able to type in your own question on the Ask-an-Expert portion. An Extension horticulture professional or a Master Gardener will reply to the question, in most cases, within 48 hours. Then an email alert is sent to you, with a link to the personalized answer. I personally check this website for incoming questions and provide answers when I can. If you would like one of your questions to be included in this iGrow Gardens column, just include “Farm Forum” at the beginning of your question so that I will be able to see that you might like to see your question show up in the column. I will check the site and use some selected questions and answers in upcoming columns.