Want Bigger Pumpkins This Fall? Do These 4 Easy Tasks Now to Give Gourds a Huge Boost Before August Ends

Whether you are growing pumpkins for Jack o’ lanterns, fall decor, fairs, or food, now is the time to push that extra oomph to ensure a bountiful autumn harvest. August may be a challenge in your area due to excessive heat, drought periods, or an increase in bug and disease activity. That is why it is important to keep up with consistent watering, proper feeding, and insect scrutiny this month.

The vines should have ample fruit set by now so it’s important to support their development in the final stretch rather than coaxing more fruit or leaves. Decreasing nitrogen fertilizer and ramping up the potassium will focus plant energy on the developing fruit.

Growing pumpkins doesn’t need to be overwhelming, but following a few tried-and-true suggestions will keep your pumpkins from withering on the vine or becoming a bug buffet.

What to Do for Pumpkins in August

Here are four tasks to perform in August to keep your pumpkins on the right track to maturity and harvest.

1. Water Deeply

Water pumpkins deeply once or twice a week. They need from 1 to 2 inches (2.5-5 cm) per week. Pumpkins are 90 percent water, so keeping up with consistent watering will ensure your pumpkin vines are hydrated and can carry nutrients from the soil to the pumpkins.

Water will prevent leaf wilt and stress, but often wilting pumpkin leaves occur on hot afternoons then perk up in the evening. If they don’t perk up by morning, there is cause to suspect vine borers.

Always water from below and keep the water from splashing on the leaves to prevent fungal diseases. Drip irrigation is ideal. Content Editor Laura has used this easy-to-install drip irrigation kit from Home Depot for years and loves it.

Cleaning up the vines and removing them to the trash at the end of the season also will help prevent fungal spores from overwintering in the debris. To keep the fruit dry and rot free, place a thin board, shingle, tile, or stone under developing fruit. Also, carefully rotating the pumpkins every week or two keeps them developing evenly.

2. Reduce Nitrogen Fertilizer

The pumpkin vines are already set with fruit by now. They do not need more vegetative growth, but they do need a potassium boost to support strong stems and fruit quality.

If you have been fertilizing pumpkins regularly, reduce the nitrogen from now on and supplement with a fertilizer that's higher in potassium, like this one from Espoma on Amazon. Or you can sidedress the pumpkin patch with compost to enrich the soil.

About 4 to 6 weeks before you expect to harvest, stop all feeding so the pumpkins focus on ripening.

3. Monitor for Insects & Disease

Squash bugs, squash vine borers, and powdery mildew are still a threat to pumpkins in late summer. Check the undersides of leaves for orange to red squash bug eggs or the grayish adults. Pick off these common pumpkin pests when you see them and drop them in a bowl of soapy water. They will be slower in the early morning. Lightly squash the eggs or remove them with masking tape.

Vines that stay limp likely have a squash vine borer tunneling inside the vines. Inspect the limp vine for an entry hole with frass below. If there is only one entrance, you may be able to save the vine by removing the larva.

Using a clean blade, make a vertical cut an inch or two (2.5-5 cm) from the entry hole. If you see the larva, remove it, kill it, and cover the cut with soil. With any luck new roots will grow at the nearest node. If unsuccessful, remove the failing vine so the borers do not pupate in the ground to emerge next year.

Powdery mildew thrives in humid, shady conditions and is characterized by a white, powdery substance on the leaves. Keeping water off the leaves helps with prevention. But once the problem starts, you can’t cure it. However, you can stop it from spreading.

Remove the leaves that are most infected with the mildew and increase air circulation. There are organic and chemical controls available, but they work better when used as a prevention. You can use a sulfur-based fungicide now, according to label directions, to stop the spread. This copper fungicide from Bonide on Amazon is another good choice.

Powdery mildew doesn’t usually kill the vines, but it is unsightly. If powdery mildew is a problem every year, you might consider starting a spray program before it starts or at the initial onset until the humid weather subsides. Some resistant pumpkin varieties are available, too.

4. Stop New Fruit Production

To stop any new pumpkin production that probably won't mature by fall anyway, pinch off new female flowers and new growing tips at the end of main vines. Female flowers have a bulbous growth below the petals. Pruning pumpkins this way redirects energy to the existing squash.

Any new fruit that sets after mid-August should be removed as well. This forces the plant to focus its energy on ripening the existing fruit and encourages bigger pumpkins. Though you may be sacrificing more squash, each pumpkin will be larger.

Pumpkins are a popular and fun plant to grow, and providing consistent water, feeding, and vigilant care right up until pumpkin harvesting time will ensure your squash make it to the finish line.