Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant iresene in Zone 1a by checking out the USDA zone info.

Planting Calendar for Iresene

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

Iresene require warm weather 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 iresene in Zone 1a is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant iresene and expect a good harvest is probably July. If you wait any later than that and your iresene may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your iresene indoors.

Last Frost Date

The average date of last frost is June 15 in Zone 1a. In the coldest months of winter you should expect an average low temperature of -60°F.

Since the USDA zone info for Zone 1a is just an average the actual date of last frost changes from year to year. Since half of the time in Zone 1a it frosts late in the year after June 15 be ready to protect your iresene if you have a surprise late frost.

USDA Zone Info for Zone 1a

Here is the info for USDA Zone 1a.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-60°F
Highest Expected Low	-55°F

This means that on a really cold year, the coldest it will get is -60°F. On most years you should be prepared to experience lows near -55°F.

Plants to Grow in Zone 1a

You may be interested in your other planting guides for Zone 1a.