The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Commerce you can figure out when to plant dahlias by referring to the USDA zone info.

Planting Calendar for Dahlias

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

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

The earliest that you can plant dahlias in Commerce 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 grow to maturity. If you are starting your dahlias 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 March 15 in Commerce. It might get as low as 10°F during the coldest months of winter.

Since the USDA zone info for Commerce is not always accurate the actual date of last frost will vary from year to year. Half of the time in Commerce last frost occurs after March 15 so make sure that you are prepared to cover your dahlias in the event of a surprise late frost.

USDA Zone Info for Commerce

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Commerce

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