The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of making a decision about when you can plant stevia is to examine the USDA zone info for Helena.

Planting Calendar for Stevia

Frost tolerance for stevia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Stevia do not do well in cold weather which tells us that it's important to wait until it warms up after all chance of frost has passed before you can plant them.

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

The last month that you can plant stevia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your stevia may not have a chance to fully mature. If you are starting your stevia indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Helena. You should expect an average low temperature of 10°F in the coldest months of winter.

Since the USDA zone info for Helena may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Helena last frost occurs after March 15 so always be ready to cover your stevia if you have one of those late frosts.

USDA Zone Info for Helena

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Helena

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