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 reviewing the USDA zone info for Harvard it's possible to determine when it's the best time 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 tend to make it in cold weather which means that you can plant them earlier in the year than more sensitive plants.

The earliest that you can plant alyssum in Harvard 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. Starting your alyssum indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on April 15 in Harvard. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Harvard is just an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Harvard it frosts late in the year after April 15 be ready to cover your alyssum if you have a surprise late frost.

USDA Zone Info for Harvard

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 Harvard

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