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.

You will be able to estimate when it's the best time to plant achillea by reviewing the USDA zone info for Oil City.

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 quite a bit of cold which tells us that you can plant them quite a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant achillea in Oil City 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. 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 few weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Oil City. In the coldest months of winter you should expect an average low temperature of -15°F.

Since the USDA zone info for Oil City may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Oil City it frosts late in the year after April 15 so make sure that you are ready to cover your achillea in the event of one of those late frosts.

USDA Zone Info for Oil City

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 Oil City

You may be interested in your other planting guides for Oil City.