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 to plant sweet potatos is to consult the USDA zone info for Sammamish.

Planting Calendar for Sweet Potatos

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

It's probably not a good idea to plant sweet potatos until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant sweet potatos in Sammamish 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 sweet potatos and expect a good harvest is probably August. If you wait any later than that and your sweet potatos may not have a chance to fully mature. You can get started a little bit earlier by starting your sweet potatos indoors.

Last Frost Date

In Sammamish the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Sammamish and it will vary from year to year. Since half of the time in Sammamish you get surprised by a frost after March 15 be ready to cover your sweet potatos in the event of a late frost.

USDA Zone Info for Sammamish

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 Sammamish

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