One of the first steps you take when you are making a decision about 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.

The earliest that you can plant ageratum in Rialto should be figured out by looking at the USDA zone info.

Planting Calendar for Ageratum

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

It's not a good idea to plant ageratum until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant ageratum 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 ageratum and expect a good harvest is probably September. Any later than that and your ageratum may not have a chance to fully mature. You can get started a little bit earlier by starting your ageratum indoors.

Last Frost Date

The average date of last frost is January 31 in Rialto. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Rialto is an average the actual date of last frost is different every year. Since half of the time in Rialto it frosts late in the year after January 31 be ready to cover your ageratum if you have one of those late frosts.

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.