One of the first steps you take when you are estimating 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 way of estimating when to plant sunflowers is to check out the USDA zone info for San Rafael.

Planting Calendar for Sunflowers

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

Since sunflowers are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant sunflowers 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 sunflowers and expect a good harvest is probably September. If you wait any later than that and your sunflowers may not have a chance to fully mature. If you are starting your sunflowers indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost has passed 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 is just an average the actual date of last frost will vary from year to year. Since half of the time in San Rafael last frost occurs after January 31 be ready to protect your sunflowers if you have a late frost.

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.