Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Trenton you can estimate when to plant achillea by checking out the USDA zone info.

Planting Calendar for Achillea

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

Achillea can survive in cold weather which means that you can plant them a lot earlier in the year than other plants that might not handle the cold.

The earliest that you can plant achillea in Trenton 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. You can get started a couple of weeks earlier by starting your achillea indoors.

Last Frost Date

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

Remember that USDA zone info for Trenton may not be accurate from year to year and the actual date of last frost is different every year. Half of the time in Trenton it frosts late in the year after April 15 so just be sure to be ready to cover your achillea if you have a late frost.

USDA Zone Info for Trenton

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 Trenton

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