One of the first steps you take when you are estimating 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.

By looking at the USDA zone info for Helena it's possible to determine when to plant runner beans.

Planting Calendar for Runner beans

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

Runner beans do not do well in cold weather which means that you really should wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant runner beans 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 runner beans and expect a good harvest is probably August. Any later than that and your runner beans may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your runner beans indoors.

Last Frost Date

In Helena the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 10°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Helena and it will vary from year to year. Since half of the time in Helena you get surprised by a frost after March 15 be ready to protect your runner beans in the event of a surprise 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.