One of the best tools that you have as gardeners to help us estimate 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 Deerfield you can estimate when to plant rosemary by reviewing the USDA zone info.

Planting Calendar for Rosemary

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

Rosemary do ok in cold weather which tells us that you can plant them quite a bit earlier in the year than more sensitive plants.

The earliest that you can plant rosemary in Deerfield 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 rosemary and expect a good harvest is probably September. If you wait any later than that and your rosemary may not have a chance to really do well. You can get started a little bit earlier by starting your rosemary indoors.

Last Frost Date

On average the last frost is on April 15 in Deerfield. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Deerfield may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Deerfield you get surprised by a frost after April 15 be ready to protect your rosemary in the event of one of those late frosts.

USDA Zone Info for Deerfield

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 Deerfield

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