Which Way Should a Squash Trellis Face?

Squash are annual plants that grow on vines. Summer squash varieties have a short growing period, and they include yellow squash and zucchini (both Cucurbita pepo). Thick, hard-skinned, winter squash plants include Hubbard (Cucurbita maxima var. "Hubbard") and acorn (Cucurbita pepo var. turbinata), and they take longer than summer squash varieties to mature. All kinds of squash perform best when they receive lots of sunlight. So a trellis that supports squash plants should be situated accordingly or the plants won't do as well as they could.

A trellis typically consists of netting, chicken wire or galvanized wire fencing suspended between two wood or metal stakes pounded into the ground. Sink the stakes deep enough to provide stability for the structure during strong wind. For example, a 6-foot-tall stake should be pounded 1 foot into the ground. Plant squash plants at the trellis' base, and train the vines to clime the netting or wire. Fashion cloth slings to support varieties that produce large plants and/or large fruits.

The trellis' placement should allow the squash plants to capture the maximum amount of full sunlight. Squash seeds don't germinate well when their soil temperature is below 60 degrees Fahrenheit, and squash plants grow best at 65 to 95 degrees Fahrenheit. The plants need at least six to eight hours of full sunlight daily; 10 to 12 hours is even better for squash such as zucchini. Give the squash plants on your trellis the sunlight they need by facing the trellis to the south or southwest. Squash growing on a south-facing trellis are subjected to damaging frost in early spring less often than squash on a trellis facing a different direction; they also get more hours of summer sunlight each day. If you can’t face your trellis south or southwest, face it west. Your plants will not get enough sunlight if the trellis faces east, and facing the trellis to the north is even worse; you may wind up with squash plants that never mature fully.

Although facing the trellis south will give your squash plants the maximum sunlight they need to mature, angling the trellis to capture even more sunlight is better. Drive the trellis' stakes into the ground at an angle so the trellis leans to the north. The stakes may need braces to support them. The squash fruits will hang from the trellis' bottom, making them easier to harvest.

Do not locate your trellis at the bottom of a hill; it’s colder there than elsewhere. For the same reason, do not situate the trellis at the bottom of a slope bordered by a fence. The trellis also should not be near trees and/or tall shrubs, which may shade the squash plants. Also, tree and shrub roots may compete with the squash plants' roots for water and nutrients.