The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

A way of making a decision about when to plant rosemary is to examine the USDA zone info for Superior.

Planting Calendar for Rosemary

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

Rosemary are very cold tolerant which means that you can start planting them much earlier than other frost tender plants.

The earliest that you can plant rosemary in Superior 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. You probably don't want to wait any later than that or else your rosemary may not have a chance to grow to maturity. Starting your rosemary indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Superior the average date of last frost happens on May 15. In the coldest months of winter you should expect an average low temperature of -25°F.

Remember that USDA zone info for Superior may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Superior you get surprised by a frost after May 15 be ready to protect your rosemary if you have a surprise late frost.

USDA Zone Info for Superior

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 Superior

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