One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Smithfield you can determine when to plant yarrow by referring to the USDA zone info.

Planting Calendar for Yarrow

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

You can plant yarrow much earlier in the year because they do well in cold.

The earliest that you can plant yarrow in Smithfield 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. Any later than that and your yarrow may not have a chance to fully mature. If you are starting your yarrow indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost is on March 15 in Smithfield. In the coldest months of winter you can expect an average low temperature of 10°F.

Since the USDA zone info for Smithfield may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in Smithfield you get surprised by a frost after March 15 be ready to protect your yarrow if you have one of those late frosts.

USDA Zone Info for Smithfield

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Smithfield

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