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.

A common way of determining when it's the best time to plant dahlia is to check out the USDA zone info for Donna.

Planting Calendar for Dahlia

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

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

The earliest that you can plant dahlia in Donna is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant dahlia and expect a good harvest is probably September. Any later than that and your dahlia may not have a chance to fully mature. You can get started a few weeks earlier by starting your dahlia indoors.

Last Frost Date

The average date of last frost is February 15 in Donna. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Donna may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Donna you get surprised by a frost after February 15 so make sure that you are prepared to cover your dahlia in the event of a late frost.

USDA Zone Info for Donna

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Donna

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