When you have eagerly awaited a plentiful harvest of squash (Cucurbita spp.) From thick, vigorously growing annual vines, it’s disappointing to discover that some of the stems have split and began dying immediately. Splitting and dying squash stems may only be the consequence of strong winds or heavy creation, or it may be proof of a serious pest issue.
Natural Factors
Squash plants have long, hollow stems, and the weight of thick, lush leaves or a great deal of large squash can stress that the stems and cause them to split. In addition, strong gusts of wind cause the spindly stems to turn and bend, stressing the plant tissue to the point of splitting. Although these splits are not ideal, they typically won’t kill the plant. Just take some soil and mound it around the stems around the very first batch of leaves, ensuring it covers the split. That helps stabilize the plant and maintains the split plant tissue from drying out.
Squash Vine Borers
Squash vine borers (Melittia spp.) , the larvae of black hawk moths, are some of the most common and damaging squash pests. The borers make miniature cracks in stem bases that allow them to tunnel into the plant tissue and start feeding. Without intervention, those small entry cracks can turn into full-blown stem splits. Borer feeding action cuts off the flow of water and nutrients, which causes influenced stems to suddenly wilt and die. The pests attack plants in warm weather, and once they’re done killing your plants, then the borers exit the squash plants and burrow into the soil to pupate over the ground.
Ongoing Squash Borers
Preventing squash vine borer infestations is much easier than treating existing pest issues. Cover young squash seedlings with lightweight floating row covers and anchor the ends using soil. Remove covers once the flowers start blooming so pollinating insects can reach the flowers. After removing the covers, wrap aluminum foil or a pair of old pantyhose around exposed plant bases and stems to prevent the adult moths from laying eggs on the plants.
Killing Squash Borers Naturally
Squash vine borers excrete a orange material that looks like sawdust. You may see this orange frass falling from tiny holes in the squash plant’s stems. Use a sharp razor blade or narrow knife to carefully make a vertical slit just above a frass-filled hole and pull out the larva using tweezers. Cover the split region with moist soil or mulch to encourage new roots to develop. Dip your cutting instrument along with the tweezers in a solution of 1 part bleach to 9 parts water between each use to prevent spreading plant diseases.
Chemical Borer Control
Treating squash plants using a carbaryl-based insecticide efficiently controls squash vine borers in case you time applications for prior to the pests input the plant comes. Once inside, the plant tissue shields them in insecticides. Start inspecting your plants once the vines start running, looking to get borer frass and miniature entrance cracks. Making two therapies five to seven days apart can help remove the majority of the young larvae before they could bore into the stems. Carbaryl comes in various forms, including concentrate, dust along with a ready-to-spray format that takes the guesswork out of mixing. Simply shake the bottle, attach it to your garden hose, turn on the water and spray the squash plants before the leaves glisten with moisture. Carbaryl is highly toxic to bees, so implement late in the day and avoid spraying blooming squash crops to avoid harming the pollinators. Protect yourself from chemical exposure by wearing protective clothing, gloves and goggles when mixing or spraying carbaryl solutions. Keep people and pets from this region until the treated crops have dried.