Hello again pumpkin growers. The weather may feel otherwise, but we are drawing ever closer to pumpkin planting time. Over the past couple of Garden Gossip columns, we have looked at the basics of successfully starting and growing pumpkins. While admittedly not the easiest of garden crops, they are also not the most difficult. The effort that you decide to put into your pumpkin patch will usually be reflected by the quality of the harvest you get. In other words, a little work now will mean plenty of pumpkin pies this fall.
One aspect of pumpkin growing that we never got into last week is the pests you will likely deal with. While there are not a lot of pumpkin pests, the ones we do have are horrible. Arguably the worst assault your pumpkin patch will ever face will be from striped cucumber beetles. These little oval beetles are about the size of lady bugs but with longitudinal black and yellow stripes. What cucumber beetles lack in size, they more than make up for with a voracious appetite and destructive capability. Hatching in late May or early June, cucumber beetles are drawn to any melon, cucumber, squash or pumpkin plant. Once they find the vine of their choice they begin feeding. Above ground the cucumber beetles are capable of chewing young pumpkin vines right down to the stem. The vines they don’t kill, they lay eggs on. Once the eggs hatch, the larva burrow down to the roots where they not only sap the plant’s energy by sucking on the roots, they also transfer the bacteria responsible for bacterial wilt. The way this disease works is diabolical. You can go to bed one night having toured your garden and admiring rows of stunning lush healthy pumpkin vines. Then, the next morning, you can walk the same route and those healthy vines will be hanging limply to the ground. Within a couple of days, infected vines invariably die and all the fruit is lost. Later in the fall, late hatchings of cucumber beetles will chew through the rinds of ripe pumpkins leaving access for all manner of mould and rot. Protecting your pumpkins from cucumber beetles should start as soon as the seedlings are visible. Floating row cover, a light weight white gauzy cloth, should be spread over the plants and sealed on the edges so that no cucumber beetles can crawl under it. Once the female flowers appear (the ones with the little fruit on them), remove the row cover to allow pollinators to access the flowers. There are many sprays and powders that can be used to combat cucumber beetles but they are also toxic to bees and other pollinators. It seems backwards to me to save your vines while killing the only means they have to produce fruit. There are also numerous “old house wife” remedies for cucumber beetles but I’ve tried them all and can honestly report that none of them will work in a heavy infestation. The best approach is row cover early on and then diligent hand picking after that. If the beetle numbers get high, I like to use a small hand held Dust Buster style vacuum to catch the beetles and to suck them out of the flowers where they seem to love hiding.
Another serious pumpkin pest in our area is the squash bug. This ugly grey brown member of the true bug family has a long sucking proboscis that it uses to pierce plant tissues and siphon off the plant’s life sustaining sap. One at a time, these bugs aren’t a huge issue. The problem is that they lay masses of eggs that hatch all at once and your pumpkin vine can suddenly be covered in hundreds of hungry sucking nymphs. This is often too much for the beleaguered plant to endure and it will succumb. Squash bugs can be hard to detect as both the adults and the nymphs hide on the undersides of leaves. Squishing them is a foul and smelly affair but is your best bet for control. There are sprays (organic and synthetic) that will work but they are difficult to apply as they require thorough coverage of the bottoms of the leaves to be effective. Turning leaves gently in early summer to monitor for eggs is your best defence. The eggs look like a mass of tiny orange dots and are laid in the V formed by leaf veins intersecting. Any time you can find and squish an egg mass you have saved yourself a huge headache. Floating row cover up until the time of the female flowers is also effective for early season protection.
These two pests are the worst of what your pumpkins may face but there are also other pests in play in the pumpkin patch. Squash vine borers, while not common this far north, do occur. After a mild winter like we just had their numbers seem to increase. There are also numerous aphids, thrips, leafminers and cutworms that love dining in the pumpkin patch. As daunting as all this may sound, it’s a worst case scenario and likely far more than most home growers will ever see in their small back yard garden.