Bringing Overwintered Herbs Outside

If you brought woodsy herbs such as rosemary or thyme indoors for the winter, it will soon be time to transition them for outdoor growing. This is much like hardening-off seedlings before transplanting. Indoor-grown herbs are typically somewhat dormant during the winter, receiving less light, water and nutrients than during the growing season. This allows the plant to better maintain existing vegetation, rather than putting resources into new growth when conditions are less than favorable.

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This rosemary plant was uprooted from the garden in late October, and grown indoors in a pot until late April.

First, examine the overall health of the plant. Do you see any signs of pests or disease? Remove severely affected leaves, and treat with an organic fungicide or pesticide if necessary. This rosemary did not have pests or disease, but some of the branches had died back.

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Cut off the dead branches with a pair of snips. Many of them still have edible leaves, which will be saved and stored in the pantry to eat later.

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Here, the top of the potting soil is covered with a very thick layer of brown, dead rosemary leaves. If you see these around your plant, gather up as many as you can and discard as they may harbor pest eggs, larvae or fungal spores. They can also reduce the amount of oxygen or water reaching the soil.

Apply dry or liquid fertilizer at half-strength and water thoroughly. Harden-off by bringing outside when temperatures are at least 50 degrees, and exposing the plant to at least a few hours of sunlight per day over about a week’s time. Remember, indoor light is much dimmer than outdoors, and you don’t want to burn the plants with too much exposure too soon. As the rosemary is gradually exposed to more sunlight, it’s leaves will thicken and the plant can be left outdoors for full days and gradually, nights.

This plant can continue growing in a pot, but will likely need to be transplanted to a larger container before the growing season is in full swing. Otherwise, it should be transplanted into the garden mid-late May. Full, bushy growth should resume by early June.