How to Overwinter Rosemary, Bay, and Tender Herbs

Know Which Herbs Actually Need Help

Not every herb in your garden needs a winter rescue plan. Hardy perennials like thyme, chives, oregano, and sage shrug off freezing temperatures and can stay in the ground with maybe a layer of mulch. The herbs that need your attention are the borderline-hardy and tender ones: rosemary, bay laurel, lemon verbena, scented geraniums, and tender types of lavender. These plants evolved in mild coastal or Mediterranean climates, and while a light frost won’t bother them, a hard freeze can kill the roots or the whole plant outright.

Before you do anything else, figure out which category each of your herbs falls into. If you’re not sure whether a plant is hardy where you garden, treat it as tender the first winter and watch how it performs. It’s far easier to leave a hardy plant outside next year than to replace a tender one you lost.

Decide: Bring Indoors or Protect in Place

You have two basic strategies, and the right one depends on your winter severity and how the herb is planted.

If your winters stay mostly above freezing with only occasional cold snaps, in-ground or in-pot protection often works. Pile a thick layer of straw, shredded leaves, or bark mulch around the base of the plant, extending out to the edge of the root zone. For potted herbs left outdoors, group pots together against a house wall and wrap the pots themselves in burlap or bubble wrap, since roots in containers freeze faster than roots in the ground.

If your winters regularly dip well below freezing for extended stretches, in-place protection isn’t reliable for tender herbs. Rosemary and bay laurel, in particular, tend to die back to the roots or die entirely once soil temperatures drop hard. In that case, plan to bring the plant indoors before the first hard freeze, not after.

Digging Up and Potting for the Move Indoors

Timing matters more than technique. Move plants indoors while nighttime temperatures are still comfortably above freezing, ideally several weeks before your first expected hard frost. This gives roots time to settle into a container before the shock of shorter days and dry indoor air arrives.

If the herb is already growing in the ground, dig a wide root ball, keeping as much of the fine root system intact as possible. Trim the plant back by no more than a third to reduce the leaf area the roots need to support, then pot it into a container just slightly larger than the root ball, using a well-draining potting mix. Oversized pots hold excess moisture that tender herb roots don’t want during their slow winter growth.

Before bringing any plant indoors, inspect it closely for pests and rinse the foliage with a gentle spray of water. Whatever hitches a ride on the leaves in October will have all winter to multiply once it’s inside with no natural predators around.

Where to Keep Them Indoors

Most tender herbs want the brightest spot you have, ideally a south-facing window or a dedicated indoor herb growing setup, plus cool nighttime temperatures. A spot near 55 to 65 degrees Fahrenheit during the day, dropping cooler at night, mimics the mild winters these plants are used to and keeps growth slow and compact rather than leggy.

Avoid placing pots directly above heating vents or radiators. The warm, dry air these produce is one of the fastest ways to stress rosemary and bay indoors, often showing up as browning needle tips or dropped leaves within a couple of weeks. If your only bright window happens to be near a heat source, move the plant a few feet away and let the room’s ambient light reach it instead.

If natural light is limited, a simple grow light run for twelve to fourteen hours a day can substitute for a sunny window. Herbs overwintering indoors aren’t trying to put on vigorous new growth; you’re just keeping them alive and healthy until they can go back outside.

Watering and Feeding Through Dormancy

Indoor herbs in winter need far less water than they did outdoors in summer. Growth slows dramatically, and the plant’s demand for moisture drops with it. Let the top inch or two of soil dry out between waterings, and always check by feel rather than by a fixed schedule. Overwatering, not cold, is the most common way overwintered rosemary and bay actually die indoors; soggy roots in a container with nowhere to drain quickly lead to rot.

Skip fertilizer entirely during the darkest, coolest months. These plants aren’t actively growing, and feeding a dormant or semi-dormant plant just encourages weak, stretched growth that won’t hold up once you move it back outside. Resume light feeding only once you see new growth picking up in late winter or early spring.

Watching for Pests During the Indoor Stretch

Spider mites and aphids are the two most common problems on overwintering herbs, and both thrive in the warm, dry, still air of an indoor room. Check the undersides of leaves every week or two for fine webbing, sticky residue, or clusters of small insects. Catching an infestation early, while it’s confined to one or two stems, makes it far easier to manage than waiting until it has spread across the whole plant.

Good airflow helps prevent problems before they start. A small fan set on low nearby, or simply opening a window briefly on mild days, keeps the air moving and makes conditions less hospitable to pests and fungal issues alike.

Quick recap

• Sort your herbs first: hardy perennials can often stay outside, while rosemary, bay laurel, and other tender types usually need a winter plan.
• Move tender herbs indoors before the first hard freeze, giving roots time to adjust while nights are still mild.
• Give them your brightest, coolest indoor spot, away from heating vents that dry out foliage.
• Water sparingly, checking soil moisture by feel, and skip fertilizer until new growth resumes in late winter.
• Inspect leaves regularly for spider mites and aphids, since indoor air gives pests an easy advantage.