Understanding their life cycle can be a big help in gaining the upper
hand. The pests overwinter in the adult stage under mulch and other
debris. So one tactic is to remove all the mulch in your garden about
a month after you shut things down, burn or hot-compost it and
replace it with a cover crop or a nice fresh mulch of shredded
leaves, which should be in abundance at that time of year. Or hold
off on the new mulch, place boards on the ground near where infested
plants were growing, check them every morning for adults looking for
a place to spend the winter and destroy them. (The adults; not the
And carefully mark where attacked plants were growing. Weíll explain
why in a minute.
The following season, start squash bug-prone plants a week or two
earlier than usual or buy the next biggest size than you usually get
at the garden center. If you DO start your own plants, make sure they
stay close to their artificial lights and are well fed. (If youíre
not going to keep your starts under lights, donít bother starting
them; weak, spindly, light-starved plants donít stand a chance
against these pests.) The goal here is to set big, healthy, actively-
growing plants out into the garden.
And be sure not to plant in the same spots as squash grew the
previous year! This is why you marked the location of last yearís
problems; you donít want to place your plants where overwintering
adults may already be lurking.
Remove any protective winter mulch and donít replace it, as mulch
harbors the pests. Instead spread an inch of rich, finished compost
on top of the soil to keep weeds down. It will also feed the plants
perfectly. Reapply monthly or as needed.
And yes Rachel, protect those young plants with spun polyester row
covers! Numerous studies have shown this to be the single most
effective squash bug tactic. Make sure those covers are tight to the
ground and check them frequently. Youíll have to remove the covers
when the first female flowers open, but thatís fine; by now, youíre
off to a great start. (If you just plain despise these pests, you can
always leave the covers on and hand-pollinate the plants.)
As soon as you remove your row covers, place boards loosely on the
soil alongside your plants. The adults will hide under these boards
at night, much like slugs. Unfortunately, as Oklahoma State
University entomology Professor Dr. Scott Fargo explained in an
ORGANIC GARDENING magazine back when I was Editor in í95, this
doesnít work as well in really warm climes or at the peak of summer,
as the adults hide under the boards to stay warm. But it works great
wherever and whenever nights are a little cool.
Go out early in the morning and scrape any squash bugs (and/or slugs)
off the bottoms of the boards into a bucket with some soapy water in
the bottom. Do NOT be an environmental criminal and use kerosene or
gasoline to drown insect pests; it is NOT necessary and there is no
way to dispose of that toxic waste safely and legally.
When nights are warm, dust diatomaceous earth (a mined natural
product) around the base of your plants. Incredibly sharp on a
microscopic level, it will dehydrate and desiccate any squash bugs
(and slugs) that try and cross over the white powder.
Hand pick and destroy any adults you see, especially early in the
season. Youíll greatly minimize problems if you prevent egg-laying by
those codgers from last year. Tape a mirror to the bottom of an old
hoe and use it to examine the undersides of the plantsí leaves every
morning. Destroy any shiny eggs you see; egg colors range from
yellowish-brown and bronze to brick red. Any eggs you miss will hatch
into nymphs, the wingless, immature stage of the squash bug. They
start out a pale green, darken as they get older and look a little
like smaller, doughy versions of the adults. Hand-pick or vacuum up
these evil children. Or spray them with insecticidal soap, a light
summer spray horticultural oil or a spinosad product. Call them vile
names and insult their ancestors.
And finally, plant things like alyssum, calendula, daises, dill,
fennel and mustard greens near your squash and cucumbers. Their
small, pollen-and nectar-rich flowers will attract the Tachnid fly,
an especially beneficial beneficial insect that preys on squash bugs.