Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant amaranthus in Washington should be figured out by using the USDA zone info.

Planting Calendar for Amaranthus

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

Amaranthus are not cold tolerant which tells us that you must wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant amaranthus in Washington 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 amaranthus and expect a good harvest is probably August. If you wait any later than that and your amaranthus may not have a chance to fully mature. If you are starting your amaranthus indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Washington the average date of last frost happens on March 15. You should expect an average low temperature of 10°F in the coldest months of winter.

Keep in mind 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 Washington and it changes from year to year. Half of the time in Washington it frosts late in the year after March 15 so always be ready to protect your amaranthus if you have a surprise late frost.

USDA Zone Info for Washington

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Washington

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