Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of figuring out when you can plant dahlias is to examine the USDA zone info for Cortez.

Planting Calendar for Dahlias

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

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

The earliest that you can plant dahlias in Cortez 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. You can get started a few weeks earlier by starting your dahlias indoors.

Last Frost Date

The average date of last frost is April 15 in Cortez. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Cortez is an average the actual date of last frost will vary from year to year. Since half of the time in Cortez it frosts late in the year after April 15 be ready to protect your dahlias in the event of one of those late frosts.

USDA Zone Info for Cortez

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 Cortez

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