Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when it's a good idea to plant achillea by checking out the USDA zone info for Hillsborough.

Planting Calendar for Achillea

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

Achillea tend to make it in cold weather which tells us that you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant achillea in Hillsborough 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 grow to maturity. You can get started a few weeks earlier by starting your achillea indoors.

Last Frost Date

The average date of last frost is April 15 in Hillsborough. In the coldest months of winter you can expect an average low temperature of 5°F.

Since the USDA zone info for Hillsborough may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Hillsborough you get surprised by a frost after April 15 be ready to protect your achillea in the event of one of those late frosts.

USDA Zone Info for Hillsborough

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Hillsborough

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