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

It's possible to determine when to plant dahlia by referring to the USDA zone info for Holland.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's a bad idea to plant dahlia until after the last frost because they are not cold tolerant.

The earliest that you can plant dahlia 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 dahlia and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlia may not have a chance to really do well. You can get started a couple of weeks earlier by starting your dahlia indoors.

Last Frost Date

The average date of last frost is April 15 in Holland. In the coldest months of winter you can expect an average low temperature of -5°F.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Holland and it will vary from year to year. Half of the time in Holland you get a frost after April 15 so make sure that you are prepared to cover your dahlia in the event of a surprise late frost.

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.