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.

By looking at the USDA zone info for Seattle you will be able to determine when you can plant lobelia.

Planting Calendar for Lobelia

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

Lobelia tend to make it in quite a bit of cold which tells us that you can plant them much earlier in the year than other plants that might not handle the cold.

The earliest that you can plant lobelia in Seattle 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 lobelia and expect a good harvest is probably September. If you wait any later than that and your lobelia may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your lobelia indoors.

Last Frost Date

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

Just be sure to remember that USDA zone info for Seattle is not always accurate and the actual date of last frost is different every year. Half of the time in Seattle there is a last frost after March 15 so just be sure to be ready to cover your lobelia if you have a late frost.

USDA Zone Info for Seattle

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Seattle

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