One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when it's possible to plant begonias by using the USDA zone info for Helena.

Planting Calendar for Begonias

Frost tolerance for begonias:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's not a good idea to plant begonias until after the last frost because they do not do well in cold weather.

The earliest that you can plant begonias 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 begonias and expect a good harvest is probably August. Any later than that and your begonias may not have a chance to fully mature. Starting your begonias indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Helena is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Helena you get a frost after March 15 be ready to cover your begonias if you have a late frost.

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.