One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of determining when it's possible to plant angel's trumpets is to look at the USDA zone info for San Luis Obispo.

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.

Since angel's trumpets are barely cold tolerant you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant angel's trumpets in San Luis Obispo 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 grow to maturity. Starting your angel's trumpets indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on February 15 in San Luis Obispo. In the coldest months of winter you should expect an average low temperature of 25°F.

Keep in mind that USDA zone info for San Luis Obispo is just an average and the actual date of last frost changes from year to year. Since half of the time in San Luis Obispo last frost occurs after February 15 be ready to protect your angel's trumpets if you have a late frost.

USDA Zone Info for San Luis Obispo

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 San Luis Obispo

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