The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to determine when it's a good idea to plant bittercress by looking at the USDA zone info for Kirkland.

Planting Calendar for Bittercress

Frost tolerance for bittercress:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Bittercress do well in mild cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant bittercress in Kirkland is March. However, you really should wait until April if you don't want to take any chances.

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

Last Frost Date

The average date of last frost is March 15 in Kirkland. In the coldest months of winter you can expect an average low temperature of 15°F.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Kirkland and it is different every year. Half of the time in Kirkland you get a frost after March 15 so make sure that you are ready to protect your bittercress if you have a late frost.

USDA Zone Info for Kirkland

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 Kirkland

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