STRAWBERRY RUNNER PLANTS

Strawberry plants are busily sending out runners with new plantlets. Some of these plantlets are already sending roots down into the soil. Even if they have started to root, they can be moved or redirected so that they are not crowded or growing into areas where they are not wanted.

Strawberry beds tend to get overcrowded with plants and expand in size so that is difficult to pick fruit without stepping on plants. They become less productive after a few years because plants produce less fruit as they get older. Plants also produce less fruit of smaller size when they are crowded. The plants that will produce the most fruit next year are the new runner plants developing right now.

I begin removing old plants of June bearing strawberry varieties as soon as I have enough new runner plants established to replace them. As soon as the new plants are well rooted, I cut the runners attached to the mother plant and then remove the mother plant. The new plants can be moved to respace them as necessary or remove some of them if there are too many. Strawberry plants are most productive when there is at least 6 inches between plants. You have to be ruthless in discarding plants to keep them from becoming unproductive.

If you have everbearing strawberry varieties which will produce another crop of fruit later, wait until fall to thin and reorganize your bed. This is a good time to start a new strawberry bed using recently rooted runner plants.

Reorganizing or planting strawberry plants now or in the fall will give plants more time to become established than if moved in the spring, so they will bear more fruit next year.

PROTECT TREES FROM BARK DAMAGE

Unplanted mulched areas around trees protect them from bark damage by mowers and trimmers. Tree bark is much more than a protective layer. The inner bark layers contain tubes which transfer food made by the leaves to the roots. When bark is damaged by mowers and line trimmers, some of these tubes are cut. This reduces food transfer to the roots and stunts tree growth. If bark is cut or damaged all the way around the trunk, trees will die.

Weed and grass free circles around trees can be maintained in several ways in addition to pulling or cultivation. Edging barriers such as cedar bender board, metal or plastic can be placed at the outer edge of circles. Edging prevents grass from growing into the circle. Edging can be moved outward as trees grow larger. Concrete edging can also be used, but it is difficult to enlarge. So grass free areas should be made larger in anticipation of tree growth.

The best way to prevent weed and grass growth within the circle is to apply black landscape weed barrier fabric. Landscape fabric is woven so it contains holes for air and water to pass through. The fabric is not only a physical barrier, but prevents light from reaching the soil beneath. Plants cannot grow without light. Landscape fabric is usually covered with bark or other mulch to improve appearance. After a year or two weed seeds will blow into the mulch, but they are easily controlled because of shallow roots. Do not use ordinary black plastic as a weed barrier. It does not have holes so air and water can reach the roots.

Weeds can also be controlled by spraying weed killers such as Roundup (glyphosate). Granular weed preventers such as Casoron or Trifluralin (Preen) can also be used. Corn gluten, an organic weed preventer, is usually available only from full service nurseries and garden stores.

Flowers planted around trees will also be competitive for water and nutrients, but not to the same extent as grass and weeds. I like to keep flower plantings at least 2 feet away from tree trunks.

DEAD-HEADING INCREASES FLOWERING

The main reason for removing old, dead flowers (referred to as “dead-heading”) is to improve the appearance of the landscape. However dead-heading will also increase the amount of bloom of many annual and perennial flowers. Plants produce flowers to reproduce themselves. After a flower has been pollinated and produces seed, plants often consider their job done. When dead flowers are removed, this stimulates many plants to bloom again. Some flower varieties only produce one set of bloom at a specific time of year and will not bloom again even if the flowers are removed.

Some of our most popular annual flowers either drop old flowers naturally or grow new leaves which cover the dead flowers. Petunias, Impatiens, Begonias, Marigolds, Pansies, Alyssum and Lobelia fit in this group. They continue to bloom and make a colorful show even without dead-heading. Most perennial flowers benefit by dead-heading.

LACE BUGS ATTACK AZALEAS & RHODODENDRONS

I have noticed a lot of lace bug damage recently on azaleas and rhododendrons. Azalea lace bug (Stephanitis pyrioides) is a relatively new insect pest in the Pacific Northwest. According to Washington State University Hortsence web site (http://pep.wsu.edu/hortsense/), “azalea lace bug attacks both azaleas and rhododendrons and may cause significant damage on both. Both adults and nymphs feed on the underside of leaves. Symptoms of damage are stippling, bleaching, or a silvery or yellowish (chlorotic) appearance of the leaves. The underside of the leaf will appear dirty due to the presence of insects (eggs, nymphs, and adults) and brownish or tar-like fecal spots, particularly along the leaf veins. Heavily damaged leaves may drop from the plant. Adults are about 1/10 inch long with lacy, net-like, transparent wings. The azalea lace bug has smoky, brown markings on the wings, which distinguish it from the pale whitish-tan rhododendron lace bug. The young nymph is colorless to black and spiny depending on age. The first generation of nymphs emerges in spring. Several generations may occur in a year. Since these insects overwinter as eggs laid on the leaves, evergreen varieties are most susceptible. Plants in full sun or suffering from drought suffer the most damage.”

Several insecticides will control lace bugs. The problem is getting the bottoms of all the leaves thoroughly covered. Because of this, systemic insecticides which are translocated through the plant’s circulation system are most effective. Imidacloprid is a systemic pesticide which can be applied to the soil and is taken up by the roots. It is available in several brands including Monterey Once A Year Insect Control and Bonide Systemic Insect Control granules. Acephate (Orthene) is another systemic available in both spray and granular form.

Spinosad is a new organic pesticide which is effective on a wide range of insects. It is available as Monterey Garden Insect Spray and several other brands. Neem oil is another organic pesticide which will control lace bugs.