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.

The first chance to plant potatos in Alton can be figured out by reviewing the USDA zone info.

Planting Calendar for Potatos

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

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

The earliest that you can plant potatos in Alton 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 potatos and expect a good harvest is probably September. You probably don't want to wait any later than that or else your potatos may not have a chance to fully mature. You can get started a few weeks earlier by starting your potatos indoors.

Last Frost Date

The average date of last frost is April 15 in Alton. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Alton is just an average the actual date of last frost is different every year. Since half of the time in Alton there is a last frost after April 15 be ready to protect your potatos in the event of 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.