The USDA Zone info is a great tool for gardeners to help us figure out 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 first chance to plant alyssum in Riverton should be estimated by checking out 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.

Alyssum are very cold tolerant which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant alyssum in Riverton 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. 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

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

It's important to remember that USDA zone info for Riverton is just an average and the actual date of last frost changes from year to year. Since half of the time in Riverton you get a frost after May 15 be ready to protect your alyssum if you have a late frost.

USDA Zone Info for Riverton

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 Riverton

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