Whenever your soil temperature reaches 70 degrees at planting depth and stays there. Pumpkins and winter squash will germinate in just 3-5 days when soil temperatures are between 70 and 95 degrees. At cooler temperatures, their germination can take longer. Summer squash will tolerate soil a little cooler--65 degrees is fine, though some people plant once their soil hits 60 degrees. If you don't have a soil thermometer and don't know your soil temperature, you can use the OK Mesonet temperature for your mesonet station. For that, I'd use the 3-day-average map and I'll link it below for you. The soil temperature maps update daily.

OK Mesonet Map of 3-Day Average Soil Temperature At 2" Depth

If you prefer a planting date versus planting by soil temperature, the OSU-recommended time frame to plant winter squash (which is what Seminole pumpkin is----it is not a pumpkin) is May 15 - June 15, with the May 15 date being for the southeastern most part of the state and the June 15th date being for the most northwestern part of the state. All the rest of us who live between those two extreme corners of the state can choose any date in between those two. The OSU-recommended planting dates for regular pumpkins is the same as for summer squash, April 10-30.

Seminole pumpkin is Cucurbita moschata, which is a tropical type of winter squash, so it does better if you wait and plant when the soil has reached 70 degrees. By then, the occasional late cold nights also generally have ended. Winter squash is considered very cold tender whereas pumpkins are only considered tender.

Click on the below link to see the OSU-recommended planting dates for vegetables.

OSU Garden Planning Guide

Okiedawn,

Thank you for the information. I was not sure what to do about the Seminoles. This year is so upside down and backwards, I have volunteer watermelon, tomato's and cowpeas in the garden.

I planted my winter squash this weekend, it is time, and I am in SE Oklahoma. I have had too many volunteer winter squash pop up over the last couple of weeks to ignore the signs any longer! My last holdout will be okra, for which I will wait a couple more weeks.

autheray, You're welcome. It is a backwards year. I have had cowpeas sprouting sporadically since mid-February, and everything else has sprouted, including (so far) one summer squash plant and one watermelon plant, but no winter squash plants.

krinkle, It is a crazy year here. You've likely got slightly warmer soil than I have because we are in a frost pocket and our nights stay cold ridiculously late. Now that some actual rain has fallen and the soil will be nice and moist, I expect to be out in the next couple of days sowing the summer squash and okra seeds. I'll wait a tiny bit longer for melons and winter squash. Maybe. There's too many volunteers of all kinds and I like to try to dig them up and move them and save them. Ha. If I were to try to do that this year, I'd do nothing but dig up and transplant volunteers. So many volunteers, so little time and space to move them to.

When I saw the watermelon volunteer pop up today in the onion bed, I shook my head. It is too early for that, but seeds are gonna do whatever they're gonna do.

Dawn