One of the first steps you take when you are determining 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 best time to plant dahlias in San Luis can be figured out by using the USDA zone info.

Planting Calendar for Dahlias

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

Dahlias require warm weather which means that you need to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant dahlias in San Luis is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant dahlias and expect a good harvest is probably September. 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 couple of weeks earlier by starting your dahlias indoors.

Last Frost Date

The average date of last frost is January 31 in San Luis. In the coldest months of winter you should expect an average low temperature of 30°F.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Luis and it can change quite a bit from year to year. Half of the time in San Luis there is a last frost after January 31 so always be ready to protect your dahlias in the event of one of those late frosts.

USDA Zone Info for San Luis

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in San Luis

You may be interested in your other planting guides for San Luis.