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.

It's a good idea to estimate when to plant pentas by reviewing the USDA zone info for Riverside.

Planting Calendar for Pentas

Frost tolerance for pentas:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since pentas require warm weather you must wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant pentas in Riverside is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant pentas and expect a good harvest is probably August. If you wait any later than that and your pentas may not have a chance to really do well. You can get started a little bit earlier by starting your pentas indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Riverside. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Riverside is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Riverside there is a last frost after April 15 be ready to protect your pentas if you have a late frost.

USDA Zone Info for Riverside

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Riverside

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