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

The USDA zone info for Helena can be read to determine when it's the best time to plant indian cress.

Planting Calendar for Indian cress

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

You really shouldn't plant indian cress until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant indian cress 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 indian cress and expect a good harvest is probably August. Any later than that and your indian cress may not have a chance to fully mature. If you are starting your indian cress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on 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 is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Helena last frost occurs after March 15 be ready to protect your indian cress in the event of 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.