Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Belle Plaine you should be able to estimate when you can plant rosemary.

Planting Calendar for Rosemary

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

Rosemary do well in pretty solid cold which tells us that you can plant them a lot earlier in the year than other frost tender plants.

The earliest that you can plant rosemary in Belle Plaine 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. Any later than that and your rosemary may not have a chance to fully mature. Starting your rosemary 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 May 15 in Belle Plaine. In the coldest months of winter you can expect an average low temperature of -25°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Belle Plaine and it can change quite a bit from year to year. Half of the time in Belle Plaine it frosts late in the year after May 15 so always be ready to protect your rosemary if you have a surprise late frost.

USDA Zone Info for Belle Plaine

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 Belle Plaine

You may be interested in your other planting guides for Belle Plaine.