The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of estimating when it's possible to plant portulaca is to look at the USDA zone info for Pomona.

Planting Calendar for Portulaca

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

Portulaca require warm weather which means that it's necessary to wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant portulaca in Pomona 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 portulaca and expect a good harvest is probably September. Any later than that and your portulaca may not have a chance to grow to maturity. If you are starting your portulaca 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 Pomona. In the coldest months of winter you can expect an average low temperature of 30°F.

Since the USDA zone info for Pomona 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 Pomona you get a frost after January 31 be ready to cover your portulaca if you have one of those late frosts.

USDA Zone Info for Pomona

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 Pomona

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