Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant ageratum in Mill Valley should be determined by reviewing the USDA zone info.

Planting Calendar for Ageratum

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

It's probably a bad idea to plant ageratum until after the last frost because they require warm weather.

The earliest that you can plant ageratum in Mill Valley 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 few weeks earlier.

Last Frost Date

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

Remember that the actual date of last frost is just an average because it is based on the USDA zone info for Mill Valley and it can change quite a bit from year to year. Since half of the time in Mill Valley last frost occurs after January 31 be ready to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for Mill Valley

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 Mill Valley

You may be interested in your other planting guides for Mill Valley.