The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The earliest that you can plant alyssum in Winthrop Harbor can be estimated by referring to the USDA zone info.

Planting Calendar for Alyssum

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

Since alyssum are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant alyssum in Winthrop Harbor 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. Any later than that and your alyssum may not have a chance to grow to maturity. You can get started a little bit earlier by starting your alyssum indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Winthrop Harbor. In the coldest months of winter you can expect an average low temperature of -15°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Winthrop Harbor and it changes from year to year. Since half of the time in Winthrop Harbor it frosts late in the year after April 15 be ready to cover your alyssum in the event of a surprise late frost.

USDA Zone Info for Winthrop Harbor

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 Winthrop Harbor

You may be interested in your other planting guides for Winthrop Harbor.