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 best time to plant iresene in Billings can be figured out by checking out the USDA zone info.

Planting Calendar for Iresene

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

It's a bad idea to plant iresene until after the last frost because they are not cold tolerant.

The earliest that you can plant iresene in Billings 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 iresene and expect a good harvest is probably August. Any later than that and your iresene may not have a chance to really do well. Starting your iresene indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Billings and it will vary from year to year. Since half of the time in Billings you get a frost after May 15 be ready to protect your iresene if you have a late frost.

USDA Zone Info for Billings

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 Billings

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