One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of making a decision about when it's possible to plant ageratum is to examine the USDA zone info for San Bruno.

Planting Calendar for Ageratum

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

Since ageratum do not do well in cold weather you really should wait until after the last frost has passed before you can plant them.

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

Last Frost Date

On average the last frost has passed is on January 31 in San Bruno. It might get as low as 30°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for San Bruno and it changes from year to year. Half of the time in San Bruno you get a frost after January 31 so be sure to be ready to protect your ageratum in the event of a surprise late frost.

USDA Zone Info for San Bruno

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 San Bruno

You may be interested in your other planting guides for San Bruno.