Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first chance to plant nierembergia in Belfast should be figured out by referring to the USDA zone info.

Planting Calendar for Nierembergia

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

Since nierembergia do not do well in cold weather it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant nierembergia in Belfast 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 nierembergia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your nierembergia may not have a chance to grow to maturity. Starting your nierembergia indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Belfast and it will vary from year to year. Since half of the time in Belfast you get surprised by a frost after April 15 be ready to protect your nierembergia if you have one of those late frosts.

USDA Zone Info for Belfast

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Belfast

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