One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Helena can be looked at to figure out when it's the best time to plant asparagus.

Planting Calendar for Asparagus

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

Asparagus tend to make it in cold weather which means that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant asparagus in Helena 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. If you wait any later than that and your asparagus may not have a chance to fully mature. You can get started a few weeks earlier by starting your asparagus indoors.

Last Frost Date

The average date of last frost is 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 not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Helena last frost occurs after May 15 be ready to protect your asparagus if you have a 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.