One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant skullcap in Lake Oswego should be figured out by referring to the USDA zone info.

Planting Calendar for Skullcap

Frost tolerance for skullcap:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since skullcap require warm weather you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant skullcap in Lake Oswego is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant skullcap and expect a good harvest is probably August. Any later than that and your skullcap may not have a chance to fully mature. You can get started a little bit earlier by starting your skullcap indoors.

Last Frost Date

The average date of last frost is March 15 in Lake Oswego. You can expect an average low temperature of 15°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Lake Oswego is just an average and the actual date of last frost changes from year to year. Half of the time in Lake Oswego there is a last frost after March 15 so always be ready to protect your skullcap if you have a surprise 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.