One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. 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 estimate when it's the best time to plant cantaloupes.

Planting Calendar for Cantaloupes

Frost tolerance for cantaloupes:	Not tolerant of frost.
When to plant:	After the last frost.

It's probably a bad idea to plant cantaloupes until after the last frost has passed because they are not cold tolerant.

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

Last Frost Date

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

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Helena and it changes from year to year. Half of the time in Helena you get surprised by a frost after May 15 so always be ready to cover your cantaloupes in the event of one of those late frosts.

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.