Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's possible to estimate when it's possible to plant lobelia by reviewing the USDA zone info for Napa.

Planting Calendar for Lobelia

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

You can plant lobelia much earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant lobelia in Napa 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. Any later than that and your lobelia may not have a chance to grow to maturity. If you are starting your lobelia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Napa the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Keep in mind that USDA zone info for Napa is not always accurate and the actual date of last frost is different every year. Since half of the time in Napa you get surprised by a frost after February 15 be ready to cover your lobelia if you have a surprise late frost.

USDA Zone Info for Napa

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 Napa

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