One of the best tools that you have as gardeners to help us estimate your gardening schedule is the 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.

A way of figuring out when it's a good idea to plant impatiens is to use the USDA zone info for Portsmouth.

Planting Calendar for Impatiens

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

Since impatiens are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant impatiens 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 impatiens and expect a good harvest is probably August. If you wait any later than that and your impatiens may not have a chance to fully mature. Starting your impatiens indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Portsmouth is just an average 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 ready to cover your impatiens in the event of 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.