One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Helena you will be able to figure out when it's the best time to plant cauliflower.

Planting Calendar for Cauliflower

Frost tolerance for cauliflower:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since cauliflower are moderately cold tolerant you can plant them a little bit earlier in the year than more sensitive plants.

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

The last month that you can plant cauliflower and expect a good harvest is probably September. You probably don't want to wait any later than that or else your cauliflower may not have a chance to fully mature. Starting your cauliflower indoors is a great way to get them started a few weeks earlier.

Last Frost Date

The average date of last frost is March 15 in Helena. It might get as low as 10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Helena is just 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 surprised by a frost after March 15 be ready to cover your cauliflower 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.