Butternut Squash in Zone 7B — Texas

Butternut squash is a winner in Texas gardens. Its sweet, nutty flavor makes it delicious roasted, in soups, or even pies. Plus, that long growing season we have means you can often get a great harvest.

Sure, the Texas heat and unpredictable weather throw curveballs, but with a little planning, you can absolutely grow butternut squash here. Our long 255-day growing season gives you a nice window to get those vines producing before the first frost.

While direct sowing is usually the way to go with squash, starting seeds indoors can give you a head start, especially if we have a late cold snap. Start your seeds late February through mid March, about three weeks before you plan to transplant. Use seed trays or small pots and keep them warm and well-lit – a sunny windowsill or grow light works great.

Bottom watering is key to prevent damping off. Just set the tray in a shallow dish of water and let the soil soak it up from the bottom. This keeps the leaves dry and prevents fungal diseases. Remember our spring weather can be early, so be ready to protect those seedlings if a late freeze threatens.

Transplant your butternut squash seedlings outdoors late March through mid April. Harden them off for about a week before planting by gradually exposing them to outdoor conditions. This helps them adjust to the Texas sun and wind.

Space the plants 36-60 inches apart to give them plenty of room to sprawl. Keep an eye on the forecast – those late cold snaps can still happen. Be ready to cover your seedlings if temperatures dip unexpectedly.

Direct sowing is the easiest way to grow butternut squash in Texas. Wait until the soil has warmed up – ideally, above 60°F – then direct sow mid March through late July. Prepare the soil by amending it with compost or well-rotted manure. Squash are heavy feeders.

Plant seeds about an inch deep, spacing them 36-60 inches apart. Water gently but thoroughly after planting. Even though we have a long growing season, starting early helps you beat some of that brutal Texas heat later in the summer.

Butternut squash needs consistent moisture, especially while the fruits are developing. During the hot Texas summers, aim for about 1-2 inches of water per week, either from rainfall or irrigation. Stick your finger about two inches into the soil – if it feels dry, it's time to water.

Water deeply at the base of the plant to encourage strong root growth. Overhead watering can lead to fungal diseases, especially with our variable humidity. As the squash matures, reduce watering slightly to improve storage quality. This helps the squash develop a thicker skin.

Signs of underwatering include wilting leaves and stunted growth. Overwatering can lead to yellowing leaves and root rot. A good layer of mulch around the plants helps retain moisture and suppress weeds. Here in Texas, I like to use shredded native tree trimmings – it breaks down slowly and enriches the soil.

Expect your first butternut squash harvest late June through mid November, about 100 days after planting. The squash is ripe when the skin turns a uniform tan color with no green streaks. The shell should be hard, and the stem should be dry and corky.

Use pruning shears or a sharp knife to cut the squash from the vine, leaving about 2-3 inches of stem attached. This helps prevent rot. Butternut squash needs to cure for about two weeks after harvest to fully develop its flavor and improve storage. Store in a cool, dry place.

As that first frost approaches in mid- November, harvest any remaining squash, even if they're not fully ripe. Smaller, less mature squash won't store as long, but they're still edible. Use them first in soups or other cooked dishes.

Here are some common problems you might face growing butternut squash in Texas:

Squash Vine Borer

• What it looks like: Wilting vines, small holes near the base of the stem, and sawdust-like frass (excrement) near the holes.
• What causes it: The larvae of a moth that bores into the stem and feeds on the plant tissue.
• How to fix/prevent it: Wrap the base of the stems with aluminum foil or pantyhose to prevent the moths from laying eggs. Inject *Bacillus thuringiensis* (Bt) into the stem to kill the larvae. You can also try to carefully slit the stem open, remove the borer, and then bury the stem in soil to encourage rooting.

Powdery Mildew

• What it looks like: White or grayish powdery coating on leaves, stems, and sometimes fruit. Leaves curl, yellow, and die. Reduces plant vigor.
• What causes it: Various fungi that thrive in warm days, cool nights, and moderate humidity. Dry leaf surfaces actually favor it (unlike most fungi).
• How to fix/prevent it: Improve air circulation through spacing and pruning. Remove affected leaves. Neem oil or potassium bicarbonate sprays help. Milk spray (1 part milk to 9 parts water) is surprisingly effective. Plant resistant varieties.

Squash Bugs

• What it looks like: Gray-brown shield-shaped bugs on leaf undersides. Bronze egg clusters on leaves. Wilting leaves that turn brown and crispy.
• What causes it: Sap-sucking insects that inject toxin while feeding. Adults overwinter in garden debris and emerge in spring.
• How to fix/prevent it: Hand-pick adults and crush egg clusters. Board traps (adults hide under boards at night — flip and destroy in morning). Neem oil spray. Remove plant debris in fall. Companion plant with nasturtiums.

Poor Pollination

• What it looks like: Fruit is small, misshapen, or fails to develop. Partially pollinated fruit develops unevenly. Flowers bloom but fall off.
• What causes it: Insufficient pollinator visits, weather too hot or cold for pollination, or timing issues (male/female flowers don't overlap).
• How to fix/prevent it: Plant pollinator-attracting flowers nearby. Hand-pollinate with a small brush. Avoid pesticides during flowering. Plant in blocks (for corn). Provide water source for pollinators.

Texas Specific Challenges: The hot-to-extreme heat can stress butternut squash plants, making them more susceptible to pests and diseases. Variable humidity and unpredictable rainfall can also create favorable conditions for fungal problems. Drought conditions can lead to blossom end rot. And of course, we've all got to watch out for fire ants when we're out in the garden.

Companion planting can really help your butternut squash thrive. Corn provides a natural trellis for the vines, and the squash helps to shade the soil, keeping it cool and moist. Green beans fix nitrogen in the soil, which benefits the squash. Radishes help deter squash vine borers. Marigolds and nasturtiums repel many pests, including squash bugs.

Avoid planting butternut squash near potatoes or brassicas (like cabbage and broccoli). Potatoes compete for nutrients, and brassicas can attract pests that also attack squash. Give your butternut squash the right neighbors, and you'll be rewarded with a bountiful harvest.