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 USDA zone info for Washington can be reffered to in order to estimate when it's possible to plant sweet williams.

Planting Calendar for Sweet Williams

Frost tolerance for sweet williams:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

You can plant sweet williams a bit earlier in the year because they are one of those plants that can tolerate a little bit of cold weather.

The earliest that you can plant sweet williams in Washington 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 sweet williams and expect a good harvest is probably September. If you wait any later than that and your sweet williams may not have a chance to grow to maturity. If you are starting your sweet williams indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Washington the average date of last frost happens on April 15. You should expect an average low temperature of -5°F in the coldest months of winter.

Remember that USDA zone info for Washington is not always accurate and the actual date of last frost is different every year. Since half of the time in Washington you get a frost after April 15 be ready to cover your sweet williams if you have a late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Washington

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