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

By looking at the USDA zone info for Red Oak you will be able to determine when it's a good idea to plant achillea.

Planting Calendar for Achillea

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

Achillea do ok in a bit of cold which tells us that you can plant them quite a bit earlier in the year than other frost tender plants.

The earliest that you can plant achillea in Red Oak 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 fully mature. If you are starting your achillea indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Red Oak the average date of last frost happens on April 15. You can expect an average low temperature of -20°F in the coldest months of winter.

Remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Red Oak and it is different every year. Half of the time in Red Oak last frost occurs after April 15 so make sure that you are prepared to cover your achillea if you have one of those late frosts.

USDA Zone Info for Red Oak

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Red Oak

You may be interested in your other planting guides for Red Oak.