Boone County Buzz: We Love Squash (So Do Bugs)

round zucchini growingWhen I hear stories of gardeners abandoning cucurbits (AKA zucchini and other squash) on people’s doorsteps, I wish this was my problem. Why do I have trouble growing these plants? I don’t use pesticides. If you want to kill some bees and reduce your yield, treat your zucchini plants with an insecticide.

Kathy Doisy

Kathy Doisy

My first job at MU was on an EPA program called “Rebuttable Presumption Against Registration.” Our job was to send the EPA data on the pros and cons of using various pesticides. Essentially asking whether the risk was worth the benefit. Based on that experience, when it comes to flea and tick control I’m on-board with man-made chemicals. (I apologize to my Kitty Boys but there is nothing worse than a home flea infestation). However, putting chemicals on something I’m eventually going to eat just doesn’t happen unless it’s absolutely, positively necessary. That means that to harvest a lot of squash and other cucurbits I have to do some serious plant monitoring. My methods are working pretty well, as we have gone from losing our plants to insect pests by the first of July, to harvests still going on in September (knock on wood)! My freezer is filled every year with my version of a delicious summer squash bisque! (If you want the recipe email me!)

adult squash bug

Figure 1. Squash bug approximately ½ to ¾ inch long. Photo, Keith Weller, USDA.

When it comes to growing squash or cucumbers around here, the big problems are squash bugs, squash borers and cucumber beetles. Anyone who has ever grown squash two years in a row knows what a squash bug looks like (Figure 1). The squash borer adult is more elusive (Figure 2). Our cucumber beetles tend to be the twelve-spotted variety (Figure 4).

adult squash vine borer, photo by Jesse Christopherson

Figure 2. Squash borer approximately ½ to ¾ inch long. Photo, Jesse Christopherson

Here’s what is working for me with the squash bugs and borers.

First, I clean up my garden waste after the first hard freeze in the fall. This way I’m removing overwintering sites for many pests including the squash bugs. Then in the spring, I plant two separate patches with summer squash as far apart as possible and leave 4 or 5 plants per mound. Depending on your garden size I recommend planting your cucumbers and winter squash in the same fashion. It may be crowded at first but it is inevitable in gardens over a year old that one of these pests will kill some of your plants.

Most mornings I get up early (it’s really nice out then — it’s cool, the birds are singing), I put on my flexible garden gloves, take my 5-gallon bucket of soapy water and an aerial (butterfly) net to the garden. First I sneak up on my plants looking for adult squash borers laying eggs near the base of my plants. It’s their larvae in the plant stems that make your otherwise healthy zucchini plant suddenly collapse and die. If you see one you have to act FAST. I swoop the net on top of it and then hold up the end of the net so they will fly up into it. Catching them on the wing is more difficult, but when you succeed it’s thrilling (well at least for a 62 year-old woman).

Squash bug eggs and immature squash bugs. Photo, Zsofia Szendrei,

Figure 3. Squash bug eggs and immature squash bugs. Photo, Zsofia Szendrei, Michigan State University

Then, when I’m done scouting for those I start looking for adult and immature squash bugs, but more importantly squash bug eggs (Figure 3). These are usually laid in clusters anywhere on the plant. When I see the eggs or immature bugs on a plant leaf or stem I remove part or all of that leaf and plunge it under the water in my bucket. If I see an adult or near-adult bug I crush it with my gloved hand or step on it. I’ve killed thousands and never been hurt, so don’t be afraid to do it.

spotted cucumber beetle

Figure 4. Spotted cucumber beetle approximately 1/3 inch long. Photo, DrPhotoMoto

Unfortunately I don’t have much luck removing cucumber beetles by hand. The damage they do to my cucumbers by feeding is negligible, but they do a lot of damage by transmitting a bacterial wilt, which is why I plant several vines on each patch. Usually one of them makes it! For other ideas on how to deal with these pests, take a look at the websites below.

Missouri Botanical Garden – Cucumber beetles

Missouri Botanical Garden – Squash borers

Missouri Botanical Garden – Squash bugs

The Boone County Buzz: Bugs in Your Broccoli?

Kathy Doisy

Kathy Doisy

“Cruciferous” vegetables include cabbage, broccoli, kale, cauliflower, arugula, and the list goes on. These crops love cooler weather and are known as “super” foods, because they are packed with nutrition. I don’t grow large quantities of them. It’s not that we don’t like them, but from past experience it seems like all the “heading” types become ready to harvest almost simultaneously. If you don’t have a big family or like to do serious fermenting, pickling and/or canning, it may cause more stress than pleasure. So, if you do like broccoli, cabbage or cauliflower, but have never grown them, I have a suggestion. On March 24th and 25th, the CGC will be offering transplants of these cool season vegetables at the Claudell garden. Why not ask for a couple of each? That way you can see how it goes without being forced to get 4-6 of them at the nursery or big box store. Also, please remember when picking up these plants that a donation helps us keep all of this going!

cabbage white butterflies

cabbage white butterflies (photo Masaki Ikeda)

Another reason for the scarcity of these types of veggies in my garden is the large number of insect pests that LOVE cruciferous plants. I don’t like to use chemicals, especially on the parts of a plant I’m going to eat. This means that for each cruciferous vegetable that I do grow I spend a lot of time monitoring it for pests.

When I walk out for my daily garden inspection I’m always wearing lightweight, flexible gardening gloves and carrying a bucket of soapy water. This allows me to crush or drown every garden pest I encounter. (Though bunnies and turtles get a pass.) For someone who has pet spiders in her home, I can be surprisingly vicious when it comes to biological control on my plants. Another possibility is row covers which will at least slow down the flying pests. Our long-time board member Bill McKelvey says that he grew spectacular cauliflower and broccoli last year using row cover, so I’m going to give it a try. The materials for row covers will be available along with seeds and the transplants at the Claudell Garden on the aforementioned dates.

garden beds demonstrating use of row cover with hoops, photo by Mark The Trigeek

Using row cover and hoops over a garden bed. (Photo by Mark the Trigeek.)

Unfortunately, I can think of twelve different species that can wreak havoc on various cruciferous vegetables. I don’t have the time, space or inclination to address all of these potential pests and chemical-free ways to grow them, but fortunately I don’t need to. Below you will find several links where someone has already done it for me.

Identification of cruciferous insect pests:

Earth friendly suggestions for control of some of these pests

(Tip: These sites all offer recommendations on other pests, too.)