One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to estimate when you can plant rosemary by reviewing the USDA zone info for Columbus.

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 much earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in Columbus 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. You probably don't want to wait any later than that or else 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

In Columbus the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

Always keep in mind that USDA zone info for Columbus is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Columbus you get a frost after April 15 so be sure to be ready to cover your rosemary in the event of a surprise late frost.

USDA Zone Info for Columbus

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Columbus

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