One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Helena you can determine when it's the best time to plant celosia by reviewing the USDA zone info.

Planting Calendar for Celosia

Frost tolerance for celosia:	Not tolerant of frost.
When to plant:	After the last frost.

Celosia do not do well in cold weather which means that you have to wait until it warms up after the last frost before you can plant them.

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

The last month that you can plant celosia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your celosia may not have a chance to really do well. If you are starting your celosia 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 May 15 in Helena. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Helena is an average the actual date of last frost will vary from year to year. Half of the time in Helena there is a last frost after May 15 so be sure to be ready to protect your celosia if you have a surprise late frost.

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.