Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when it's the best time to plant alyssum is to look at the USDA zone info for Lewistown.

Planting Calendar for Alyssum

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

Since alyssum do well in cold you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant alyssum in Lewistown 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. If you are starting your alyssum indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Lewistown. In the coldest months of winter you should expect an average low temperature of -30°F.

Keep in mind that USDA zone info for Lewistown is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Lewistown there is a last frost after May 15 so just be sure to be ready to protect your alyssum if you have a late frost.

USDA Zone Info for Lewistown

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Lewistown

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