One of the first steps you take when you are getting a good idea 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.

By reviewing the USDA zone info for Highland Park you should be able to estimate when it's the best time to plant yarrow.

Planting Calendar for Yarrow

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

Yarrow are very cold tolerant which means that you can plant them a quite a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant yarrow in Highland Park 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 grow to maturity. Starting your yarrow indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Highland Park. You can expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Highland Park is not always accurate the actual date of last frost is different every year. Since half of the time in Highland Park there is a last frost after April 15 be ready to cover your yarrow if you have a late frost.

USDA Zone Info for Highland Park

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 Highland Park

You may be interested in your other planting guides for Highland Park.