Before planting it is a good idea to find your USDA Zone info to estimate 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.

It's possible to estimate when it's the best time to plant cauliflower by checking out the USDA zone info for Helena.

Planting Calendar for Cauliflower

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

Cauliflower do well in mild cold which tells us that you can plant them just a bit earlier in the year than more sensitive plants.

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

The last month that you can plant cauliflower and expect a good harvest is probably August. Any later than that and your cauliflower may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your cauliflower indoors.

Last Frost Date

In Helena the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Keep in mind that USDA zone info for Helena is just an average and the actual date of last frost is different every year. Half of the time in Helena you get surprised by a frost after May 15 so just be sure to 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 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Helena

You may be interested in your other planting guides for Helena.