The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant tagetes in Alton should be estimated by looking at the USDA zone info.

Planting Calendar for Tagetes

Frost tolerance for tagetes:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant tagetes until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant tagetes 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 tagetes and expect a good harvest is probably August. If you wait any later than that and your tagetes may not have a chance to fully mature. If you are starting your tagetes indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Alton is an average and the actual date of last frost changes from year to year. Half of the time in Alton you get surprised by a frost after April 15 so just be sure to be ready to cover your tagetes 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.