Saturday, July 29, 2006 - UGH!! Vine Borers - Got Into My Beautiful Zucchini!!

Cultural and Physical Controls

   Several options for squash vine borer control are available to small-scale growers. Gardeners who regularly scout their plantings can slit the stem at the entry hole and remove the larva. Covering the damaged area with a shovelful of moist soil encourages healing and new root development at the site. In fact, some gardeners routinely place a shovelful of soil at one or more locations along the stems of vining cucurbits to encourage supplementary root development and increase the plant’s ability to overcome borer attack.

   For both large and small plantings, annual rotation to non-cucurbit crops is the primary step toward cultural control of squash vine borer. Control through rotation is somewhat limited, however, as the adults are strong fliers and have been noted to find squash fields as far as ½ mile from their emergence site in an old field. Field sanitation procedures are also recommended. Vine residues should be destroyed as soon as possible after harvest to prevent late caterpillars from completing their lifecycle. Fall tillage to expose cocoons to predation and deep incorporation in early spring further help to keep populations suppressed. On the other hand, fall sanitation procedures, which leave the ground bare for extended periods, are contrary to good sustainable agriculture practice and should be used sparingly if at all.

   Sometimes vine borer injury can be offset by late planting or by staggered planting dates. (Contact Cooperative Extension for safe planting dates for a specific region.) Such strategies are especially effective if accompanied by supplementary fertilization to encourage rapid, vigorous growth. The importance of sustaining vigorous plant growth cannot be overemphasized as part of a borer control strategy. While it is true that a single borer can destroy a whole plant, vigorously-growing squash plants can tolerate 1 or 2 borers and still produce a crop through additional rooting along the stem. For this reason, there is some advantage, especially on poorer soils, to broadcasting supplementary fertilizers, rather than concentrating them in planting hills. Roving vines are more successful at setting additional roots in soil that is well-fertilized..

   Early interplanting of highly susceptible squash varieties as trap crops within or adjacent to the main crop is one means of deflecting squash vine borer. Interplanting pumpkins among corn—a traditional Native American practice—is believed effective in either confusing or repelling squash vine borer. For further information on such techniques, ask for ATTRA’s Companion Planting. publication. Early-season control can also be managed using floating row covers. These must be removed as soon as flowers emerge in order to allow pollinators access.

   At least I have learned this, and we can see how cutting the little devils out of the stem works, so maybe we will be better able to take care of them next year!  I did companion plant some of the veggies. Next year, the squash goes in with the corn and bean rows!!

   I hope you are not having the same problems we are, but, at least here is some important and useful info!