Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant radishes in Alton by referring to the USDA zone info.

Planting Calendar for Radishes

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

Radishes do well in quite a bit of cold which means that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant radishes 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 radishes and expect a good harvest is probably September. Any later than that and your radishes may not have a chance to really do well. Starting your radishes indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Alton. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Alton may not be accurate from year to year the actual date of last frost is different every year. Half of the time in Alton you get a frost after April 15 so just be sure to be ready to cover your radishes in the event of a surprise late frost.

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.