One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can figure out when you can plant melampodium in Portsmouth by referring to the USDA zone info.

Planting Calendar for Melampodium

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

It's not a good idea to plant melampodium until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant melampodium 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 melampodium and expect a good harvest is probably August. Any later than that and your melampodium may not have a chance to fully mature. You can get started a few weeks earlier by starting your melampodium indoors.

Last Frost Date

The average date of last frost is April 15 in Portsmouth. In the coldest months of winter you should expect an average low temperature of -10°F.

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

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.