Is It Too Late to Plant Pumpkins?

The honest answer to "is it too late to plant pumpkins" is that it depends on two numbers, and no search result knows both of them. One is the date your first fall frost usually arrives. The other is how many days your variety needs to finish. Put those together and the question answers itself. Below, do exactly that.

1. Where are you? 2. When would you be planting? (defaults to today)

What each variety needs

Days to maturity below are counted from sowing, and they come from each variety's own listing rather than a single rule of thumb. Treat them as a guide, not a promise. A cool, wet June or a run of 100 degree afternoons will move them either direction.

Variety	Days to maturity	Will it finish?
Autumn Crown F1 Pumpkin	90 days	,
Tromboncino Squash	60 to 90 days	,
Autumn Frost F1 Pumpkin	100 days	,
Black Futsu Squash	100 days	,
Cushaw Green-Striped Pumpkin	100 days	,
Dickinson Pumpkin	100 days	,
Spell Cast F1 Pumpkin	100 days	,
Violina Rugosa Butternut	100 days	,
Wan Fu F1 Pumpkin	90 to 100 days	,
Xiye Butternut	100 days	,
Bakers Branch Butternut	105 days	,
Cuban Neck Pumpkin	105 days	,
South Anna Butternut	105 days	,
Chinese Tropical Pumpkin	100 to 110 days	,
Honeynut Squash	110 days	,
Jamaican Tropical Pumpkin	100 to 110 days	,
Long Island Cheese Pumpkin	100 to 110 days	,
Magdalena Big Cheese	110 days	,
Mrs. Amerson's Pumpkin	110 days	,
Musquee de Maroc Pumpkin	90 to 110 days	,
Shishigatani Squash	110 days	,
Thai Kang Kob Pumpkin	110 days	,
Waltham Butternut Squash	100 to 110 days	,
New England Cheddar F1 Pumpkin	112 days	,
Guatemalan Green Ayote	105 to 115 days	,
Musquee de Provence Pumpkin	120 days	,
Pennsylvania Dutch Crookneck	110 to 120 days	,
Seminole Pumpkin	90 to 120 days	,
Tahitian Melon Squash	110 to 120 days	,
La Estrella F1 Tropical Pumpkin	125 days	,

If the answer is no

It usually is, after the middle of July in Kansas, and that is worth saying plainly instead of selling you seed for a crop that will not ripen. A pumpkin caught by frost two weeks short does not keep, does not cure, and does not bake well. Three things are still worth doing this season.

Plant something that does fit. Bush beans, spinach, radishes, and turnips all finish inside a short autumn window in zone 6b.
Feed the bed instead. A cover crop of cereal rye or crimson clover sown now will hold your soil through the winter wind and give you a better bed in May than any bag of amendment will.
Buy the seed now and plant it on time. Squash seed stays viable four to six years in a cool, dry place, so seed bought in August is fully good next May, and the varieties worth having are the ones that sell out in March.

Buying yourself more days

If you are close and want to push it, you are trying to add days at the front of the season rather than the back. Starting indoors three to four weeks early and setting out transplants is worth roughly that much. Black plastic or landscape fabric warms the soil several degrees, which matters more than most people expect, because moschata seed sulks below 65 degrees and can sit for two weeks doing nothing. At the far end, a single light frost will kill the vines but will not ruin fruit that has already coloured and hardened, so a row cover thrown over the patch the night of the first freeze can buy you the last week you needed.

Why we lean on days to maturity and not zones

Hardiness zones describe how cold a winter a perennial can survive. Pumpkins are annuals and die every autumn regardless, so a zone number tells you almost nothing about whether your crop will ripen. What matters is the length of your frost free window, which is why the tool above asks for a frost date and does arithmetic with it.

Shop the varieties above: all pumpkin and squash seed, or start with Seminole if your season is long and hot, and Autumn Frost F1 if it is not.