One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

One way of determining when it's possible to plant angel's trumpets is to use the USDA zone info for San Rafael.

Planting Calendar for Angel's Trumpets

Frost tolerance for angel's trumpets:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Angel's Trumpets do ok in moderate cold which means that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant angel's trumpets 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 angel's trumpets and expect a good harvest is probably September. You probably don't want to wait any later than that or else your angel's trumpets may not have a chance to fully mature. If you are starting your angel's trumpets indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

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

It's important to remember that USDA zone info for San Rafael is an average and the actual date of last frost is different every year. Half of the time in San Rafael last frost occurs after January 31 so be sure to be ready to protect your angel's trumpets if you have a surprise 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.