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.

By looking at the USDA zone info for San Rafael it's possible to figure out when you can plant dahlias.

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 are not cold tolerant which means that it is important to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant dahlias in San Rafael 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 few weeks earlier by starting your dahlias indoors.

Last Frost Date

On average the last frost is on January 31 in San Rafael. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for San Rafael 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 San Rafael there is a last frost after January 31 so make sure that you are prepared to cover your dahlias in the event of one of those late frosts.

USDA Zone Info for San Rafael

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 Rafael

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