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

One way of making a decision about when you can plant achillea is to consult the USDA zone info for Broken Arrow.

Planting Calendar for Achillea

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

Since achillea are very cold tolerant you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant achillea in Broken Arrow 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. You probably don't want to wait any later than that or else your achillea may not have a chance to really do well. If you are starting your achillea indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Broken Arrow the average date of last frost happens on April 15. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Broken Arrow is not always accurate the actual date of last frost will vary from year to year. Half of the time in Broken Arrow you get a frost after April 15 so always be ready to protect your achillea if you have a surprise late frost.

USDA Zone Info for Broken Arrow

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Broken Arrow

You may be interested in your other planting guides for Broken Arrow.