Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Rialto it's a good idea to determine when it's possible to plant bougainvillea.

Planting Calendar for Bougainvillea

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

It's a bad idea to plant bougainvillea until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant bougainvillea in Rialto 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 bougainvillea and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bougainvillea may not have a chance to grow to maturity. If you are starting your bougainvillea indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Rialto. You can expect an average low temperature of 30°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Rialto and it can change quite a bit from year to year. Since half of the time in Rialto there is a last frost after January 31 be ready to protect your bougainvillea if you have a late frost.

USDA Zone Info for Rialto

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 Rialto

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