The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By using the USDA zone info for Herrin you should be able to determine when it's possible to plant alyssum.

Planting Calendar for Alyssum

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

Alyssum do well in a bit of cold which tells us that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant alyssum in Herrin is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant alyssum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your alyssum may not have a chance to really do well. If you are starting your alyssum indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Herrin the average date of last frost happens on April 15. You can expect an average low temperature of -5°F in the coldest months of winter.

Since the USDA zone info for Herrin may not be accurate from year to year the actual date of last frost will vary from year to year. Half of the time in Herrin there is a last frost after April 15 so always be ready to cover your alyssum in the event of one of those late frosts.

USDA Zone Info for Herrin

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Herrin

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