Whether you’re looking to grow your own Jack o’ Lanterns or growing them as a food crop, knowing when to plant pumpkin seeds will improve your harvest. The best time for planting pumpkin seeds depends on where you live and when you’d like your pumpkins to be ready for harvest.
Preparing the Seeds
Whenever you plant them, there are a few things you can do to improve the germination rate of your pumpkin seeds. Because they have such a hard shell, filing the edges of pumpkin seeds (except at the pointy end) will make it easier for seedlings to emerge. Also, soak your seeds in warm water for a few hours before planting, and then plant one to two inches below the surface either sideways or pointy end down.
In the Garden
Pumpkins are not hardy, so in colder climates the best time to plant pumpkin seeds is in late May, after all danger of frost has passed. Pumpkin vines grow very quickly, especially in warm climates, so Southern gardeners should wait to plant until early summer. Pumpkin seeds won’t germinate in cold soils (less than 65°F), so planting them in mounds of soil will help to artificially increase soil temperature. Make sure the soil is heavily amended with good organic matter to accommodate pumpkin’s heavy feeding habits. Plant three to five seeds per mound, then thin to the two strongest seedlings.
If you’re growing a food crop or looking to grow a giant Jack o’ Lantern, you may want to start your pumpkin seeds indoors to get a jumpstart on the growing season. Start your seeds two to three weeks before the last annual frost. Because pumpkin seedlings grow very quickly, it’s a good idea to use large peat pots so you won’t be rushed into planting them outside before the weather warms. Put a layer of sterile compost at the bottom of the pot to encourage deep root growth, then fill with good quality potting soil. Water well and place by a southern facing window. Pumpkin seeds need heat at the bottom of the container to germinate, so invest in a heated germination pad.