One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By referring to the USDA zone info for Trenton you will be able to figure out when it's a good idea to 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 ok in cold weather which tells us that you can plant them a lot earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant rosemary in Trenton 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. If you are starting your rosemary indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Trenton the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Trenton may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Trenton last frost occurs after April 15 be ready to cover your rosemary in the event of one of those late frosts.

USDA Zone Info for Trenton

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Trenton

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