For many gardeners a live rosemary plant pruned into the conical shape of a Christmas tree is an edible fragrant evergreen. It’s fitting that rosemary would play a role for the holidays because since ancient Greece, rosemary was thought to strengthen memories.
The rosemary tree (Rosmarinus officinalis) is a half hardy perennial that will burst with fragrance whenever the branches are touched.
Even though these miniature trees are sold as live plants they have a tendency to die soon after arrival in heat of a winter home.
The reason is usually two fold: the plants are pot bound and they dry out quickly in the relatively low humidity indoors.
The secret is to replant the rosemary immediately into larger clay pots as soon as you get them home. Choose a good all purpose potting soil. Since good drainage is essential you can even add up to 10 per cent perlite or sand to the soil.
Keep them well watered but not soggy, and place them in the brightest spot in the room.
It will need good light, at least six hours a day. If your rosemary tree starts to drop needles, move it where there is more light.
Keep rosemary, or any house plant, away from drafts. . Place the tree on a dish of pebbles filled with water and mist it once in awhile to keep the humidity high.
Rosemary can be subject to powdery mildew fungus. This fungus will appear as a white powder on the leaves. Usually powdery mildew grows when your rosemary tree isn’t getting enough light. Cut and remove any infected branches. You can also control powdery mildew with a natural treatment of wettable sulfate powder such as Remedy Fungicide. When the plant is actively growing in the spring and summer, you can use a regular houseplant