One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to determine when it's a good idea to plant columbine by reviewing the USDA zone info for Three Rivers.

Planting Calendar for Columbine

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

Columbine can survive in mild cold which tells us that you can plant them just a bit earlier in the year than other frost tender plants.

The earliest that you can plant columbine in Three Rivers 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. Any later than that and your columbine may not have a chance to grow to maturity. If you are starting your columbine indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Three Rivers the average date of last frost happens on April 15. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Three Rivers is not always accurate the actual date of last frost is different every year. Since half of the time in Three Rivers you get surprised by a frost after April 15 be ready to protect your columbine if you have a surprise late frost.

USDA Zone Info for Three Rivers

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 Three Rivers

You may be interested in your other planting guides for Three Rivers.