One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when it's the best time to plant celosia is to look at the USDA zone info for Alton.

Planting Calendar for Celosia

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

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

The earliest that you can plant celosia 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 celosia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your celosia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your celosia indoors.

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.

Just be sure to remember that USDA zone info for Alton is not always accurate and the actual date of last frost is different every year. Since half of the time in Alton you get surprised by a frost after April 15 be ready to protect your celosia in the event of a 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.