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.

By reviewing the USDA zone info for Zone 4a you should be able to determine when it's possible to plant scutellaria.

Planting Calendar for Scutellaria

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

Scutellaria require warm weather which means that it's necessary to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant scutellaria 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 scutellaria and expect a good harvest is probably August. If you wait any later than that and your scutellaria may not have a chance to fully mature. If you are starting your scutellaria indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Zone 4a. It might get as low as -30°F during the coldest months of winter.

Remember that USDA zone info for Zone 4a is an average and the actual date of last frost can change quite a bit from year to year. Since half of the time in Zone 4a there is a last frost after May 15 be ready to cover your scutellaria in the event of a surprise 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.