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.

You should be able to estimate when it's the best time to plant columbine by looking at the USDA zone info for South Holland.

Planting Calendar for Columbine

Frost tolerance for columbine:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Columbine tend to make it in some cold which tells us that you can plant them a little earlier in the year than other plants that might not handle the cold.

The earliest that you can plant columbine in South Holland is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant columbine and expect a good harvest is probably September. If you wait any later than that and your columbine may not have a chance to grow to maturity. Starting your columbine indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in South Holland. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for South Holland is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in South Holland it frosts late in the year after April 15 be ready to protect your columbine if you have one of those late frosts.

USDA Zone Info for South Holland

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 South Holland

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