One of the best tools that you have as gardeners to help us determine 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.

In Watertown you can figure out when to plant asparagus fern by using the USDA zone info.

Planting Calendar for Asparagus Fern

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

It's not a good idea to plant asparagus fern until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant asparagus fern in Watertown 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. If you wait any later than that and your asparagus fern may not have a chance to really do well. 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 Watertown. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Watertown is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Watertown there is a last frost after May 15 so make sure that you are ready to protect your asparagus fern if you have a surprise late frost.

USDA Zone Info for Watertown

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 Watertown

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