Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Helena you can figure out when it's the best time to plant turnips by referring to the USDA zone info.

Planting Calendar for Turnips

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

Turnips are not cold tolerant which tells us that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant turnips 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 turnips and expect a good harvest is probably August. If you wait any later than that and your turnips may not have a chance to fully mature. If you are starting your turnips indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Helena the average date of last frost happens on March 15. It might get as low as 10°F during 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 changes from year to year. Since half of the time in Helena there is a last frost after March 15 be ready to cover your turnips in the event of 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.