One of the first steps you take when you are determining 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.

You should be able to determine when to plant lobelia by reviewing the USDA zone info for Fairfax.

Planting Calendar for Lobelia

Frost tolerance for lobelia:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since lobelia are one of those plants that can tolerate quite a bit of cold weather you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant lobelia in Fairfax is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant lobelia and expect a good harvest is probably October. You probably don't want to wait any later than that or else your lobelia may not have a chance to fully mature. Starting your lobelia indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Fairfax the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Fairfax is not always accurate the actual date of last frost is different every year. Half of the time in Fairfax it frosts late in the year after February 15 so make sure that you are ready to protect your lobelia if you have one of those late frosts.

USDA Zone Info for Fairfax

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Fairfax

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