Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to determine when it's the best time to plant blue throatwort by referring to the USDA zone info for Harwood Heights.

Planting Calendar for Blue Throatwort

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

You can not plant blue throatwort until after the last frost because they require warm weather.

The earliest that you can plant blue throatwort in Harwood Heights is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant blue throatwort and expect a good harvest is probably August. If you wait any later than that and your blue throatwort may not have a chance to fully mature. You can get started a little bit earlier by starting your blue throatwort indoors.

Last Frost Date

On average all chance of frost has passed is on April 15 in Harwood Heights. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Harwood Heights is just an average the actual date of last frost will vary from year to year. Since half of the time in Harwood Heights it frosts late in the year after April 15 be ready to cover your blue throatwort in the event of one of those late frosts.

USDA Zone Info for Harwood Heights

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Harwood Heights

You may be interested in your other planting guides for Harwood Heights.