One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A common way of getting a good idea when it's possible to plant achillea is to look at the USDA zone info for Columbia.

Planting Calendar for Achillea

Frost tolerance for achillea:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Achillea do well in cold which tells us that you can plant them much earlier than plants that are more sensitive to the cold.

The earliest that you can plant achillea in Columbia 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 achillea and expect a good harvest is probably September. If you wait any later than that and your achillea may not have a chance to grow to maturity. Starting your achillea indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is March 15 in Columbia. It might get as low as 15°F during the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Columbia and it changes from year to year. Since half of the time in Columbia you get a frost after March 15 be ready to protect your achillea in the event of a late frost.

USDA Zone Info for Columbia

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in Columbia

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