One of the best tools that you have as gardeners to help us determine your gardening schedule is the 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 making a decision about when it's a good idea to plant yarrow is to look at the USDA zone info for Crest Hill.

Planting Calendar for Yarrow

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

Since yarrow are very cold tolerant you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant yarrow in Crest Hill 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 really do well. If you are starting your yarrow indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Crest Hill the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Crest Hill and it can change quite a bit from year to year. Half of the time in Crest Hill last frost occurs after April 15 so make sure that you are ready to cover your yarrow if you have a late frost.

USDA Zone Info for Crest Hill

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 Crest Hill

You may be interested in your other planting guides for Crest Hill.