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When to Plant Sweet Williams in Washington, IA

Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of getting a good idea when it's possible to plant sweet williams is to use the USDA zone info for Washington.

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Planting Calendar for Sweet Williams

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

Sweet Williams are one of those plants that can tolerate a little bit of cold weather which tells us that you can plant them earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant sweet williams
Possibly ok, but a risky time to plant sweet williams
Probably not a good time to plant sweet williams

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 really do well. If you are starting your sweet williams indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Washington. In the coldest months of winter you can expect an average low temperature of -15°F.

Keep in mind that USDA zone info for Washington may not be accurate from year to year and the actual date of last frost changes from year to year. Half of the time in Washington you get surprised by a frost after April 15 so be sure to be ready to cover your sweet williams if you have a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°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 -10°F.

Plants to Grow in Washington

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