One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

It's possible to determine when it's possible to plant asparagus fern by checking out the USDA zone info for Zone 4a.

Planting Calendar for Asparagus Fern

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

Asparagus Fern require warm weather which tells us that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant asparagus fern in Zone 4a 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 asparagus fern and expect a good harvest is probably August. Any later than that and your asparagus fern may not have a chance to grow to maturity. Starting your asparagus fern indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4a. You can expect an average low temperature of -30°F in the coldest months of winter.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Zone 4a and it changes from year to year. Half of the time in Zone 4a you get a frost after May 15 so be sure to be ready to cover your asparagus fern if you have a late frost.

USDA Zone Info for Zone 4a

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zone 4a

You may be interested in your other planting guides for Zone 4a.