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.

By looking at the USDA zone info for Alton you should be able to figure out when it's a good idea to plant stoneseed.

Planting Calendar for Stoneseed

Frost tolerance for stoneseed:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

It's probably not a good idea to plant stoneseed until after the last frost because they are not cold tolerant.

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

The last month that you can plant stoneseed and expect a good harvest is probably August. Any later than that and your stoneseed may not have a chance to really do well. You can get started a little bit earlier by starting your stoneseed indoors.

Last Frost Date

On average the last frost is on April 15 in Alton. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Alton is an average the actual date of last frost will vary from year to year. Since half of the time in Alton it frosts late in the year after April 15 be ready to cover your stoneseed if you have one of those late frosts.

USDA Zone Info for Alton

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Alton

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