One of the first steps you take when you are getting a good idea 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 estimating when it's the best time to plant ageratum is to examine the USDA zone info for Monrovia.

Planting Calendar for Ageratum

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

Ageratum are not cold tolerant which means that you must wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Monrovia 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 really do well. If you are starting your ageratum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Monrovia. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for Monrovia is not always accurate the actual date of last frost is different every year. Since half of the time in Monrovia you get surprised by a frost after January 31 be ready to protect your ageratum in the event of one of those late frosts.

USDA Zone Info for Monrovia

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 Monrovia

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