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 determine when you can plant chrysocephalum by looking at the USDA zone info for Portsmouth.

Planting Calendar for Chrysocephalum

Frost tolerance for chrysocephalum:	Not tolerant of frost.
When to plant:	After the last frost.

Since chrysocephalum do not do well in cold weather you need to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant chrysocephalum in Portsmouth 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 chrysocephalum and expect a good harvest is probably August. Any later than that and your chrysocephalum may not have a chance to really do well. You can get started a little bit earlier by starting your chrysocephalum indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Portsmouth. In the coldest months of winter you can expect an average low temperature of -10°F.

Keep in mind that USDA zone info for Portsmouth may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Portsmouth you get surprised by a frost after April 15 so make sure that you are prepared to cover your chrysocephalum if you have one of those late frosts.

USDA Zone Info for Portsmouth

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°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 -5°F.

Plants to Grow in Portsmouth

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