"Meeting the Challenge"
from Practical Gardener, January 2002 issue.

This "challenge" deals with two strategies in one - blocking an insect and modifying the environment.

With any "enemy," it is useful to first understand the foe to defeat it. Though I have no desire to be on a first-name basis with a "worm," this holds true for the squash vine borer. It is this understanding that provided a way to meet and beat this challenge.

The squash vine borer can be a big obstacle to growing pumpkins, squash and even zucchini! Once in your garden, it can be like a boorish "friend" that comes for a visit - and never elaves. Since the pest is nearly imporrible to throw out, the challenge is to succeed despite its presence.

With many insects, the damage is not done by the adults. It is the juveniles that produce the real harm. The same is true in this case, but the trouble starts with the parent.

The "mama" moth lays its eggs on the host plant - usually near the base - in June and early July (in zones 3 to 5). Eggs hatch and the young bore into the base of the plants. As borers grow, they eat up into the stem and eventually cut off most or all of the flow of water and nutrients from the roots to the rest of the plant.

The borer grows from an egg smaller than a millet (bird) seed to a "worm" about 1 1/2 inches in length and about as big around as a pencil. It is about this time gardeners may come out one morning and find their squash has "wilted."
Squash tend to wilt some with warm weather, so it is easy to dismiss the dropping as being natural.

However, when the plant does not recover after watering, a gardener may realize there is a problem. At this point, it becomes a salvage operation, which is like deciding to cover plants on a frosty night - the day after it froze.

The Solution

Knowing that is the larva that does the real damage led me to try for a solution that prevented the eggs from being laid in the first place. To do this, I put a barrier between the mother moth and the squash plants.

I used a "Guarden" structure to keep the moths out. However, you can keep the plants covered just so long or you won't get any squash. Unless you hand pollinate the squash flowers, you need to allow pollinating insects such as bees access to the plants. And when you let the bees "in," the door is open for the vine borers, as well.

Fortunately, the "tent" not only kept the insects away, it also created a warmer environment - which is ideal for a heat-loving crop like squash. So by the time I needed to lift the cover, the plants were far bigger than those grown in the open. So instead of having a small, vulnerable plant for a host, the moth found a full-sized squash plant. She laid her eggs on all the plants. But the bigger ones were strong enough and far enough along to outgrow the damage the borers did.

The Results

I started the same number of buttercup squash plants inside and outside of the "Guarden" on the same date. The only difference was keeping the cover on for seven weeks.

The results speak volumes. The pile on the right is from the protected plants.
They produced over four times as many squash - even more by weight - than the unguarded plants. Their production is on the left.

Ultimately, I met this challenge by finding a way to "live with the problem." The moth laid her eggs, but "too late" to be fatal to the plants.

-Glen Ring

Meeting the Challenge is a theme introduced in the November special issue. The goal of this series is to deal with problems and challenges that tend to be at the "root" of many frustrations. It may be an ongoing fight with a disease, certain insects, soil problems, climate (too hot, cold, dry, short, etc.) and many more. But whatever it is, meeting that challenge is likely to be key to ongoing success for those facing that obstacle. In a sense, it's like taking the restraints off and setting you and your garden free.