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

In Portland you can determine when it's the best time to plant amaranthus by checking out the USDA zone info.

Planting Calendar for Amaranthus

Frost tolerance for amaranthus:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since amaranthus require warm weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant amaranthus in Portland is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant amaranthus and expect a good harvest is probably September. Any later than that and your amaranthus may not have a chance to grow to maturity. Starting your amaranthus indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Portland the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Portland is just an average the actual date of last frost can change quite a bit from year to year. Half of the time in Portland last frost occurs after February 15 so be sure to be ready to cover your amaranthus in the event of a late frost.

USDA Zone Info for Portland

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Portland

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