I got this beautiful rosemary tree as a gift this Christmas, and I hope to help it to live to see a Christmas future. I think its chances are good even though overwintering rosemary indoors used to be quite a challenge for me. In climates where the winters are not as harsh, it can be left outside and will eventually grow into a large shrub. Here in zone 5b you can try leaving it out for the winter if you’ve planted it in a spot with a warmer microclimate. Even then, however, you’ll need to protect it if a severe freeze comes along. Someday, when I’m braver, I will try leaving a rosemary plant outside and see what happens.
“There’s Rosemary for you, that’s for remembrance! Pray you, love, remember.”
WILLIAM SHAKESPEARE, HAMLET
For now I just grow it in containers and bring those containers inside for the winter. Alas, rosemary doesn’t like the dry heat in my home even though we have a whole house humidifier. I tried a number of things in the past—pebble trays, misting, and even a terrarium—but met with little success.
I know I’m not the only one who struggles to keep rosemary alive. How many of you have bought a sweet little rosemary tree during the holiday season only to see it fizzle out by February? Take courage, for here are some tips to remember.
- Plant rosemary in a large container. Do not plant it in the ground if you hope to bring it inside for the winter. Rosemary doesn’t like to be transplanted, and when you combine transplanting it with moving it inside, it will most likely die. You don’t have to start with a large container if the plant is small when you get it. But be prepared to pot it up as needed until you have a plant that is growing in a container that’s 14” in diameter and at least 12” deep (about 6-7 gallons). Rosemary roots can grow to be 12-24” deep. In the spring I will transplant this rosemary tree from its 1-gallon size container into a larger pot.
- Place rosemary close to a sunny window, preferably one that’s badly insulated. The cool air by such a window is more humid than the rest of the house. Mine is on the floor next to a sliding glass door that leads to our deck.
- Most importantly, do not over-water it. Rosemary tricks us because when we see its leaves dying back and turning brown, we think we should water it more. But this can easily lead to root rot because rosemary is one of those herbs that thrives in dry well-drained soil. Don’t water it when the plant looks dry; water it when the soil is all dry. At that point I take mine to the sink and give it a thorough watering. Then I leave it there until it’s fully drained. After I return it to its saucer, I don’t water it again until the soil has dried.
With these tips, you’ll be able to enjoy rosemary all winter long even if you don’t live in a rosemary friendly climate.
For you there’s rosemary and rue; these keep seeming and savour all the winter long
WILLIAM SHAKESPEARE, A WINTER’S TALE
The Gardener Wife 