One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You should be able to estimate when to plant yarrow by looking at the USDA zone info for Princeton.

Planting Calendar for Yarrow

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

Yarrow do well in cold weather which tells us that you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant yarrow in Princeton 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 yarrow and expect a good harvest is probably September. If you wait any later than that and your yarrow may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your yarrow indoors.

Last Frost Date

On average the last frost has passed is on April 15 in Princeton. In the coldest months of winter you can expect an average low temperature of -5°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Princeton and it is different every year. Half of the time in Princeton last frost occurs after April 15 so make sure that you are ready to cover your yarrow if you have a surprise late frost.

USDA Zone Info for Princeton

Here is the info for USDA Zone 6b.

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

Plants to Grow in Princeton

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