Regardless of the type of pumpkin you choose to plant, you have to wait until the right time of year to plant them. Despite the temptation to plant as soon as the spring days are warm, hold off until the soil itself is warm.
The ideal soil temperature for planting pumpkins is 65°F (18°C), and the soil does not begin to warm up until the last heavy frost of the year. Depending on the growing zone in which you live, this could be as early as May or as late as July.
Tip: You can find your growing zone by asking seasoned gardeners in your area or consulting a local nursery.
When is it Too Late?
The latest time to plant pumpkins for an autumn harvest depends on several different things, like the kind of pumpkin you plant and the length of the growing season.
For example, pumpkins with a short growing season, like small decorative pumpkins, can likely wait until the first week of July since they only require about 85 days to mature.
However, larger pumpkins like the traditional Jack O’Lantern size can take as long as 125 days, while a massive Giant Pumpkin needs at least 165 days of growing time.
Can I Speed Up the Planting Process?
The reality is that nature takes as long as she takes, and there is no way to force pumpkin seeds to grow before the temperature of the soil is warm enough. Many gardeners become impatient with the process and do some of the following things:
Start seeds indoors 4-6 weeks prior to the last frost date.
Purchase established seedlings from a local nursery.
Use heavy mulch and black plastic to warm the earth and keep vulnerable plants safe from frost.
These can be especially useful methods if the pumpkin variety requires a longer growing season than you have.
The Bottom Line
The time to plant pumpkin seeds depends on a variety of factors. Although you can get a head start by pre-planting seeds indoors or buying strong seedlings, the pumpkin still needs a set time in the ground before harvest can occur. Pay attention to the growing season, and you will have the yield you want.