The USDA Zone info is a great tool for gardeners to help us estimate 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.

A common way of figuring out when it's the best time to plant alyssum is to look at the USDA zone info for Holmen.

Planting Calendar for Alyssum

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

You can plant alyssum much earlier in the year because they are very cold tolerant.

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

The last month that you can plant alyssum and expect a good harvest is probably August. If you wait any later than that and your alyssum may not have a chance to grow to maturity. Starting your alyssum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Holmen the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Holmen and it changes from year to year. Half of the time in Holmen you get a frost after May 15 so be sure to be ready to protect your alyssum in the event of one of those late frosts.

USDA Zone Info for Holmen

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Holmen

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