The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to estimate when it's possible to plant amaranthus by referring to the USDA zone info for Calistoga.

Planting Calendar for Amaranthus

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

Amaranthus are not cold tolerant which tells us that you really should wait until it warms up after the last frost before you can plant them.

The earliest that you can plant amaranthus in Calistoga 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. If you wait any later than that and your amaranthus may not have a chance to really do well. Starting your amaranthus indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on February 15 in Calistoga. You can expect an average low temperature of 20°F in the coldest months of winter.

Remember that USDA zone info for Calistoga is not always accurate and the actual date of last frost is different every year. Since half of the time in Calistoga you get a frost after February 15 be ready to cover your amaranthus in the event of one of those late frosts.

USDA Zone Info for Calistoga

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Calistoga

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