One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Bethalto should be reffered to in order to estimate when it's the best time to plant dahlias.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Dahlias are not cold tolerant which means that it's important to wait until it warms up after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant dahlias in Bethalto 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 dahlias and expect a good harvest is probably August. If you wait any later than that and your dahlias may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your dahlias indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Bethalto. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Bethalto is an average the actual date of last frost will vary from year to year. Half of the time in Bethalto you get a frost after April 15 so make sure that you are prepared to protect your dahlias if you have a surprise late frost.

USDA Zone Info for Bethalto

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 Bethalto

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