One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

A common way of getting a good idea when to plant yarrow is to use the USDA zone info for New Castle.

Planting Calendar for Yarrow

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

Since yarrow do well in cold 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 yarrow in New Castle 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 really do well. You can get started a little bit earlier by starting your yarrow indoors.

Last Frost Date

In New Castle the average date of last frost happens on April 15. You should expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for New Castle is just an average the actual date of last frost changes from year to year. Half of the time in New Castle last frost occurs after April 15 so make sure that you are prepared to cover your yarrow if you have a late frost.

USDA Zone Info for New Castle

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in New Castle

You may be interested in your other planting guides for New Castle.