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 USDA zone info for Downers Grove can be reffered to in order to figure out 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 all chance of frost has passed.

Since dahlias do not do well in cold weather it is necessary to wait until after the last frost has passed before you can plant them.

The earliest that you can plant dahlias in Downers Grove 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. You probably don't want to wait any later than that or else your dahlias may not have a chance to fully mature. If you are starting your dahlias indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Downers Grove the average date of last frost happens on April 15. You can expect an average low temperature of -15°F in the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Downers Grove and it changes from year to year. Since half of the time in Downers Grove you get a frost after April 15 be ready to protect your dahlias if you have one of those late frosts.

USDA Zone Info for Downers Grove

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Downers Grove

You may be interested in your other planting guides for Downers Grove.