One of the best tools that you have as gardeners to help us figure out 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 Zone 4a you can determine when to plant asparagus by looking at the USDA zone info.

Planting Calendar for Asparagus

Frost tolerance for asparagus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since asparagus are very cold tolerant you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant asparagus in Zone 4a 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 asparagus and expect a good harvest is probably August. You probably don't want to wait any later than that or else your asparagus may not have a chance to grow to maturity. You can get started a little bit earlier by starting your asparagus indoors.

Last Frost Date

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

Since the USDA zone info for Zone 4a is an average the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 4a last frost occurs after May 15 so make sure that you are prepared to protect your asparagus in the event of one of those late frosts.

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.