One of the best tools that you have as gardeners to help us figure out 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.

The USDA zone info for Holland can be used to determine when it's a good idea to plant nierembergia.

Planting Calendar for Nierembergia

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

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 Holland 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 fully mature. Starting your nierembergia indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Holland. In the coldest months of winter you can expect an average low temperature of -5°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Holland and it can change quite a bit from year to year. Since half of the time in Holland you get surprised by a frost after April 15 be ready to protect your nierembergia in the event of one of those late frosts.

USDA Zone Info for Holland

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Holland

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