Acorn Squash in Zone 6A — Southeast

Acorn squash is a rewarding addition to any Southeastern garden. Its sweet, nutty flavor shines in everything from simple roasted sides to hearty fall soups. Plus, the satisfaction of harvesting your own winter squash after our long summer is hard to beat.

While our hot and humid summers can bring some challenges, especially with fungal diseases, Acorn Squash matures relatively quickly. With smart timing and a little extra attention, you can easily grow a bountiful crop within our long, 198-day growing season.

Starting Acorn Squash indoors isn't essential here in the Southeast, but it can give you a slight head start. If you choose to go this route, aim to sow your seeds indoors from late March through mid April, about three weeks before you plan to transplant them outside.

Use seed trays filled with a good seed-starting mix, and keep them in a warm spot with plenty of light – a sunny windowsill or under grow lights works well. Make sure to water from the bottom of the tray to prevent damping off. With our moderate springs, starting indoors isn't always worth the effort, but it's an option if you're eager to get a jump on the season.

Transplanting Acorn Squash seedlings outdoors should happen from late April through late May, once the danger of frost has passed. Before transplanting, harden off your seedlings by gradually exposing them to outdoor conditions for about a week.

Space your plants 36-48 inches apart to allow for plenty of room to vine. Keep an eye on the weather forecast; those late-season cold snaps can still happen, so be prepared to cover your young plants if necessary.

Direct sowing is the easiest and most common method for growing Acorn Squash in the Southeast. Wait until the soil has warmed up, usually from mid April through mid July, to sow your seeds directly into the garden.

Prepare your planting beds by amending our often-heavy clay soil with plenty of compost to improve drainage and fertility. Plant seeds about an inch deep, spacing them 36-48 inches apart. Winter squash needs a long season, but direct sowing works well here since our summers are long and reliable.

Acorn Squash needs consistent watering, especially during its active growth period, but be careful not to overdo it, especially with our humid conditions. Aim for about 1 inch of water per week, either from rainfall or irrigation.

Stick your finger about 2 inches deep into the soil – if it feels dry, it's time to water. Water at the base of the plant to avoid wetting the leaves, which can encourage fungal diseases in our humid climate. As the fruits mature, you can reduce watering slightly.

Overwatering can lead to root rot, while underwatering can stress the plants and reduce fruit production. Watch for signs like wilting leaves (even in the morning) or yellowing foliage. A good layer of mulch around the plants can help retain moisture and suppress weeds, just be mindful of good airflow to prevent moisture build-up.

You can expect your first Acorn Squash harvest from mid July through late October, about 85 days after planting. The best indicators of ripeness are a dark green skin with a noticeable orange spot where the squash has been resting on the ground.

The shell should be hard, and the stem should be dry and tough. Use a sharp knife or pruners to cut the squash from the vine, leaving a few inches of stem attached to prevent rot.

As our first frost approaches in late October, harvest any remaining squash, even if they're not fully ripe. While they won't ripen off the vine, you can still use them in cooking.

Here are some common problems you might encounter with Acorn Squash in the Southeast:

Squash Vine Borer

• What it looks like: Wilting vines that suddenly collapse, often with small holes near the base of the plant and sawdust-like frass.
• What causes it: The larvae of a moth that burrows into the stem and feeds on the plant tissue. Our long, hot summers provide ideal conditions for these pests.
• How to fix/prevent it: Wrap the base of the stems with aluminum foil to prevent the moths from laying eggs. Inspect stems regularly and remove any borers you find. You can also try injecting Bacillus thuringiensis (Bt) into the stems to kill the larvae.

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.

Cucumber Beetles

• What it looks like: Small yellow-green beetles with black spots or stripes on leaves and flowers. Leaves have small holes. Plants may wilt suddenly from bacterial wilt transmitted by beetles.
• What causes it: Adult beetles feed on leaves and flowers and transmit bacterial wilt disease. Larvae feed on roots.
• How to fix/prevent it: Row covers until flowering (remove for pollination). Hand-pick adults. Yellow sticky traps. Neem oil or pyrethrin spray. Kaolin clay coating. Interplant with radishes or nasturtiums as trap crops.

Southeast Specific Challenges: Our hot and humid climate means that fungal diseases like powdery mildew are a constant threat. Regular monitoring, good air circulation, and preventative treatments are key. The humidity also favors pests like squash bugs and cucumber beetles, so stay vigilant and take action early.

Good companions for Acorn Squash include corn, which provides support for the vines to climb. Green beans add nitrogen to the soil, benefiting the squash. Radishes can deter pests like squash vine borers. Marigolds planted nearby can repel nematodes and other harmful insects.

Avoid planting Acorn Squash near potatoes, as they compete for nutrients. Brassicas like cabbage, broccoli, and cauliflower can also inhibit squash growth. These combinations are especially important to avoid in our Southeast gardens where competition for nutrients can be intense.