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

In Lake Oswego you can figure out when it's possible to plant larkspur by checking out the USDA zone info.

Planting Calendar for Larkspur

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

Since larkspur do well in cold you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant larkspur in Lake Oswego 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 larkspur and expect a good harvest is probably September. If you wait any later than that and your larkspur may not have a chance to really do well. You can get started a couple of weeks earlier by starting your larkspur indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on March 15 in Lake Oswego. In the coldest months of winter you should expect an average low temperature of 15°F.

It's important to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Lake Oswego and it can change quite a bit from year to year. Half of the time in Lake Oswego last frost occurs after March 15 so make sure that you are ready to protect your larkspur if you have a late frost.

USDA Zone Info for Lake Oswego

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 Lake Oswego

You may be interested in your other planting guides for Lake Oswego.