The USDA Zone info is a great tool for gardeners to help us estimate 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.

The USDA zone info for Portsmouth can be read to estimate when it's the best time to plant doronicum.

Planting Calendar for Doronicum

Frost tolerance for doronicum:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Doronicum do well in some cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

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

The last month that you can plant doronicum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your doronicum may not have a chance to grow to maturity. Starting your doronicum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Portsmouth may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Portsmouth there is a last frost after March 15 be ready to cover your doronicum if you have a surprise late frost.

USDA Zone Info for Portsmouth

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 Portsmouth

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