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.

A common way of estimating when it's the best time to plant alyssum is to examine the USDA zone info for Mill Creek.

Planting Calendar for Alyssum

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

Alyssum do ok in cold weather which means that you can plant them much earlier in the year than plants that are more sensitive to the cold.

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

Last Frost Date

In Mill Creek the average date of last frost happens on March 15. In the coldest months of winter you can expect an average low temperature of 15°F.

Since the USDA zone info for Mill Creek is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Mill Creek you get a frost after March 15 so always be ready to protect your alyssum in the event of one of those late frosts.

USDA Zone Info for Mill Creek

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 Mill Creek

You may be interested in your other planting guides for Mill Creek.