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

By looking at the USDA zone info for Silvis 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.

Since rosemary do well in cold you can plant them earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in Silvis 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. Any later than that and your rosemary may not have a chance to fully mature. You can get started a little bit earlier by starting your rosemary indoors.

Last Frost Date

The average date of last frost is April 15 in Silvis. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Silvis may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Silvis you get a frost after April 15 be ready to protect your rosemary if you have a late frost.

USDA Zone Info for Silvis

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 Silvis

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