Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Worthington you can figure out when you can plant rosemary by looking at 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 can survive in a bit of cold which tells us that you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant rosemary in Worthington is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant rosemary and expect a good harvest is probably August. If you wait any later than that and your rosemary may not have a chance to fully mature. If you are starting your rosemary 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 when the weather gets warmer is on May 15 in Worthington. In the coldest months of winter you should expect an average low temperature of -25°F.

Keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Worthington and it is different every year. Since half of the time in Worthington it frosts late in the year after May 15 be ready to cover your rosemary if you have one of those late frosts.

USDA Zone Info for Worthington

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Worthington

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