One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Riverside should be reffered to in order to estimate when it's possible to plant angel's trumpets.

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 mild cold which means that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant angel's trumpets in Riverside 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. Any later than that and your angel's trumpets may not have a chance to really do well. Starting your angel's trumpets indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Riverside the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 25°F.

Always keep in mind that USDA zone info for Riverside is an average and the actual date of last frost changes from year to year. Half of the time in Riverside it frosts late in the year after February 15 so just be sure to be ready to cover your angel's trumpets in the event of a surprise late frost.

USDA Zone Info for Riverside

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 Riverside

You may be interested in your other planting guides for Riverside.