Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Helena should be used to determine when you can plant pumpkins.

Planting Calendar for Pumpkins

Frost tolerance for pumpkins:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Pumpkins are not cold tolerant which means that it is necessary to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant pumpkins in Helena is May. However, you really should wait until June if you don't want to take any chances.

The last month that you can plant pumpkins and expect a good harvest is probably August. You probably don't want to wait any later than that or else your pumpkins may not have a chance to really do well. Starting your pumpkins indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost is on May 15 in Helena. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Helena may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Helena you get a frost after May 15 be ready to cover your pumpkins if you have a late frost.

USDA Zone Info for Helena

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Helena

You may be interested in your other planting guides for Helena.