A container herb garden does not need to be a seasonal project. With the right selection of herbs, a modest investment in lighting, and a simple transition plan, you can grow fresh herbs 12 months of the year — outdoors from spring through fall, and indoors through winter. The herbs that grow on your patio in July can move to a sunny windowsill in November and back outside in April. The cycle repeats year after year, and the plants get bigger, bushier, and more productive with each pass.
Most gardeners treat herbs as a warm-weather luxury. They buy transplants in May, enjoy fresh basil through September, toss the dead plants in October, and spend the next six months buying plastic clamshells of sad, wilted herbs from the grocery store at four dollars each. That cycle is unnecessary. A handful of perennial herbs — rosemary, thyme, sage, oregano, chives, mint — are perfectly capable of surviving indoors through winter with nothing more than a bright window and careful watering. And the annual herbs that cannot survive winter — basil, cilantro, dill — can be sown fresh from seed indoors under a simple grow light and harvested within weeks.
This guide provides a month-by-month calendar for managing a container herb garden through all four seasons. It covers which herbs to grow in each phase, when and how to transition between outdoor and indoor growing, what light requirements look like for winter indoor production, and the specific techniques for hardening off indoor herbs for their return to the outdoor season. If you want purpose-built containers for your herb garden, our cedar window herb boxes are sized specifically for windowsill growing and transition easily between indoor and outdoor positions.
The Outdoor Season: April Through October
The outdoor season is the easy phase. Most culinary herbs are sun-loving plants that thrive in containers on a patio, deck, balcony, or doorstep that receives at least six hours of direct sunlight per day. Container culture actually suits herbs well — the confined root zone, fast-draining soil, and warm microclimate of a sun-baked pot concentrate essential oils and produce more flavorful herbs than the same plants grown in rich, moist garden beds.
April (or after last frost). Move overwintered perennial herbs back outdoors after hardening off (more on this process below). Start basil, cilantro, and dill seeds indoors under lights, or purchase transplants once nighttime temperatures reliably stay above 50 degrees Fahrenheit. If you kept rosemary, thyme, sage, and oregano alive through winter indoors, they are ready to resume vigorous growth once they return to outdoor sun and warmth. Check the soil surface of perennial containers — refresh the top inch with fresh potting mix and a light application of slow-release fertilizer to kick off the growing season.
May through June. Peak planting and establishment. Move basil transplants outdoors after nighttime temperatures are above 55 degrees consistently. Basil is tropical — it does not tolerate cold nights and grows slowly until warmth arrives. Set up your full outdoor herb display — group containers where you can access them easily from the kitchen, which encourages daily harvesting. Begin pinching basil aggressively once it has three sets of leaves. Pinch every growing tip back to the first set of leaves below it. This forces lateral branching and produces a bushy plant with four times the harvestable leaf area compared to an unpinched plant that grows into a single tall stem and flowers.
Sow cilantro every two to three weeks for succession — cilantro bolts quickly in warm weather, and a single sowing provides only three to four weeks of harvestable leaves before it runs to seed. Accept this rhythm rather than fighting it. Harvest cilantro leaves heavily when they are available, and let the plants flower and produce coriander seed when they bolt — the seeds are a different but equally useful spice.
July through August. Peak harvest and maintenance. Herbs grow fastest in the long, warm days of midsummer. Harvest regularly — cutting herbs stimulates new growth and prevents flowering, which reduces leaf flavor in most species. Water containers daily or twice daily in extreme heat. Fertilize every two weeks with a balanced liquid feed at half strength. Monitor for pests — spider mites and aphids are most active in hot, dry conditions and love container herbs.
This is also the season when Mediterranean herbs — rosemary, thyme, oregano, sage — are at their most flavorful. The combination of heat, sun, and the mild drought stress that containers naturally provide concentrates essential oils in the foliage. Harvest these herbs for drying during midsummer for the strongest preserved flavor.
September through October. The transition begins. As days shorten and nights cool, herb growth slows. Basil is the first casualty — it blackens at the first touch of frost and declines rapidly when nighttime temperatures drop below 50 degrees. Harvest basil heavily in September. Make pesto. Freeze whole leaves. Dry what you can. Once nighttime temperatures threaten to drop below 45 degrees, pull the basil plants — they are done for the year.
Cilantro and dill get a second wind in fall. Both are cool-season herbs that bolt in summer heat but grow beautifully in the shorter, cooler days of early fall. Sow fresh seeds in September containers for a fall harvest that rivals the spring crop.
Perennial herbs — rosemary, thyme, sage, oregano, chives, mint — continue growing into fall and can tolerate light frost. Let them stay outdoors as long as possible to accumulate the cold exposure that triggers dormancy. Begin preparing for the indoor transition in late September: identify your indoor growing location, clean windows, set up supplemental lighting if needed.
The Fall Transition: Moving Herbs Indoors
The transition from outdoor to indoor growing is the most critical phase of the year-round herb cycle. Done poorly, it shocks plants, introduces pests to your home, and produces leggy, struggling herbs that limp through winter. Done well, it is a smooth handoff that keeps herbs growing with minimal interruption.
Timing. Move herbs indoors before nighttime temperatures consistently drop below 40 degrees Fahrenheit. For rosemary, the threshold is slightly higher — bring it in when nights approach 35 degrees, as rosemary is the least cold-tolerant of the common perennial culinary herbs. The goal is to make the move while the plant is still actively growing, not after it has been stressed by cold.
Pest inspection. This is non-negotiable. Every container that comes indoors must be inspected and treated for pests. Aphids, spider mites, whiteflies, fungus gnats, and slugs all ride in on outdoor containers and will infest your indoor environment if given the chance. Spray all foliage — upper and lower leaf surfaces — with insecticidal soap one week before the move. Remove dead leaves and debris from the soil surface. Check the drainage holes and under the pot rim for slugs and pill bugs. Repot into fresh soil if you have any suspicion of soil-dwelling pests like fungus gnat larvae.
Acclimatization. The shift from outdoor sun to indoor light is dramatic. Even a bright south-facing window provides only a fraction of the light intensity that herbs received outdoors. An abrupt move from full sun to indoor light causes leaf drop, yellowing, and stress. Ease the transition over one to two weeks: start by moving containers to a shaded outdoor location (porch, under a tree canopy) for several days, then to a bright indoor window. This gradual reduction in light levels gives the plant time to adjust its leaf physiology to lower light conditions.
Winter Indoor Growing: November Through March
Winter is the challenging phase. Light levels drop, day length shortens, indoor air is dry from heating systems, and the growing conditions that herbs evolved for are largely absent. Success indoors depends on managing three factors: light, water, and expectations.
Light. This is the limiting factor. A south-facing window in the northern hemisphere receives four to six hours of direct light on a clear winter day — roughly half what herbs receive outdoors in summer. That is enough for herbs that tolerate lower light: parsley, chives, mint, and cilantro. It is marginal for rosemary, thyme, and oregano, which are full-sun plants that become leggy and weak in low light. It is insufficient for basil, which needs at least eight hours of bright light to grow properly.
Supplemental grow lights solve the light problem reliably. A simple LED grow light strip or panel positioned 6 to 12 inches above your herb containers for 12 to 14 hours per day provides enough photosynthetically active radiation for any herb to grow well indoors. LED grow lights are inexpensive (15 to 40 dollars for a unit that covers a windowsill's worth of plants), use minimal electricity, and last for years. If you are serious about winter herb growing, a grow light is not optional — it is the difference between herbs that survive winter and herbs that thrive through it.
Position lights on a simple plug-in timer so they turn on and off automatically. Herbs do not need 24-hour light — 14 hours on, 10 hours off mimics a long summer day and keeps growth active without stressing plants. Place the light close to the foliage — 6 to 12 inches — because light intensity drops dramatically with distance. A light that seems bright at arm's length delivers a fraction of its rated output to a plant on a table three feet below it.
Water. Indoor herbs need less water than outdoor herbs because light levels are lower, growth is slower, and transpiration is reduced. Overwatering is the number one killer of indoor winter herbs. The soil surface may look dry while the lower root zone remains saturated — check moisture by inserting a finger two inches into the soil before watering. If it feels damp, wait another day. If it feels dry, water thoroughly until it drains from the bottom, then do not water again until the top two inches dry out.
Rosemary is the most overwatering-sensitive herb indoors. Its Mediterranean roots demand excellent drainage and a dry period between waterings. Indoor conditions — lower light, lower air circulation, cooler temperatures — slow drying dramatically compared to an outdoor pot in summer sun. Many gardeners lose rosemary to root rot every winter simply by watering it on the same schedule they used in July. Scale back to roughly half your summer watering frequency and let the soil dry more thoroughly between drinks.
Humidity. Heated indoor air in winter often drops below 30 percent relative humidity — drier than most deserts. Herbs tolerate low humidity better than many houseplants, but extremely dry air encourages spider mites and can cause leaf tip browning on chives and parsley. Group herb containers on a tray filled with pebbles and water — the water evaporates around the plants and raises local humidity. Do not mist herb foliage directly — wet leaves in stagnant indoor air invite fungal disease. A small humidifier near your herb growing area is the most effective solution if dry air is a persistent problem.
Growing Basil and Cilantro Indoors in Winter
Basil and cilantro are annual herbs that do not overwinter — they complete their lifecycle in one season and die. But you can grow fresh plants from seed indoors at any time of year. Winter-sown basil and cilantro under a grow light produce harvestable leaves within four to six weeks of sowing, giving you fresh herbs through the months when outdoor growing is impossible.
Sow basil seeds in a small pot of seed-starting mix, cover lightly, and keep warm (70 to 75 degrees Fahrenheit) and moist until germination in 5 to 10 days. Move seedlings under the grow light as soon as they emerge. Thin to two or three plants per pot. Begin harvesting individual leaves when plants have four to six sets of leaves, and pinch growing tips regularly to promote bushiness. A single pot of basil sown in November provides fresh leaves through January. Sow a second pot in January for February through March coverage. By April, outdoor-grown basil is about to take over again.
Cilantro is even easier. Sow seeds densely in a pot, cover with a quarter inch of soil, and keep moist. Cilantro germinates in 7 to 14 days and grows quickly under lights. It bolts less readily indoors than outdoors because indoor temperatures are cooler and more stable than summer sun. A single sowing can provide harvestable leaves for six to eight weeks indoors — longer than the same plant would last outdoors in summer heat. Sow every four to six weeks for continuous supply.
The Spring Transition: Hardening Off for Outdoors
The return trip — from indoor growing back to outdoor conditions — requires as much care as the fall transition, if not more. Indoor herbs have adapted to lower light, stable temperatures, still air, and the sheltered conditions of your home. Moving them directly into outdoor sun, wind, and temperature fluctuations causes sunburn, windburn, wilting, and potentially fatal shock.
Hardening off takes two weeks. Begin when nighttime outdoor temperatures reliably stay above 45 degrees Fahrenheit (above 55 for basil). Day one through three: place herbs outdoors in a fully shaded, wind-protected spot for two to three hours, then bring them back inside. Day four through seven: increase outdoor time to four to six hours, still in shade. Day eight through ten: move to a spot with morning sun and afternoon shade, six to eight hours outdoors. Day eleven through fourteen: full sun exposure for the full day, bringing indoors only if nighttime temperatures drop near the plant's tolerance threshold. After two weeks of this progression, herbs are acclimated and can stay outdoors permanently for the season.
Do not skip or rush hardening off. Indoor leaves have thinner cell walls and lower concentrations of protective pigments than outdoor leaves. Direct sun on unhardened foliage causes cellular damage that appears as white or brown scorched patches. Wind on unhardened stems causes breakage and desiccation. Two weeks of gradual exposure lets the plant rebuild its defenses at a pace it can sustain.
Best Herbs for Each Phase of the Year
Year-round performers (perennial herbs that transition indoors and back): Rosemary, thyme, oregano, sage, chives, and mint. These are the backbone of your year-round herb garden. They grow outdoors from April through October and move indoors for November through March. Chives and mint are the most shade-tolerant and perform best in lower indoor light. Rosemary and thyme need the most light and benefit most from supplemental grow lights.
Outdoor-only (warm-season annuals sown fresh each year): Basil (outdoor May through September), dill (outdoor spring and fall), and summer savory. These herbs do not transition indoors successfully as mature plants but can be grown from seed indoors under lights for winter harvests.
Cool-season producers (thrive in spring, fall, and cool indoor conditions): Cilantro, parsley, and chervil. These herbs bolt in summer heat but grow beautifully in the cooler conditions of spring, fall, and winter windowsill gardens. They are excellent candidates for continuous indoor sowing because they prefer the cool, moderate light conditions that indoor growing provides.
Winter indoor specialists (start from seed indoors for winter harvest): Basil (from seed under lights), cilantro (from seed under lights), dill (from seed under lights), and microgreen herbs like basil, cilantro, and fennel grown as microgreens in trays for ultra-fast winter harvests.
To keep track of your herbs throughout the year, label each container with the plant name, variety, and the date it was last repotted or sown. Our white oak herb marker sets are designed for exactly this purpose — weather-resistant markers that look as good on a winter windowsill as they do on a summer patio.
Month-by-Month Calendar Summary
January: Indoor phase. Maintain grow lights 14 hours per day. Water sparingly. Sow basil and cilantro seeds indoors for winter harvests. Inspect for spider mites — indoor winter conditions favor them.
February: Indoor phase. Days are noticeably longer. Perennial herbs may show new growth. Increase watering slightly if growth resumes. Start planning outdoor container layout for the coming season. Order seeds for spring sowing.
March: Transition preparation. Begin hardening off indoor herbs on mild days. Start basil seeds indoors 6 to 8 weeks before your last frost date. Refresh potting mix in perennial containers — top-dress with fresh mix and slow-release fertilizer.
April: Spring transition. Move hardened-off perennial herbs outdoors permanently once nighttime temperatures stay above 45 degrees. Sow cilantro and dill directly in outdoor containers. Continue basil indoors until nights are consistently above 55 degrees.
May: Full outdoor season begins. Move basil outdoors. Begin aggressive pinching and harvesting schedule. Set up succession sowing plan for cilantro (every 2 to 3 weeks). Fertilize all containers with balanced liquid feed.
June: Peak growth. Harvest daily if possible. Pinch basil, cut herbs for drying, and enjoy the abundance. Water daily in hot weather. Watch for pests — aphids and spider mites arrive with warm temperatures.
July: Midsummer peak. Dry rosemary, thyme, and oregano — essential oils are at maximum concentration. Continue harvesting and succession sowing cilantro. Deadhead chive flowers to redirect energy to leaf production.
August: Late summer maintenance. Sow fall cilantro and dill. Take cuttings of rosemary and thyme to propagate new plants for next year or for indoor winter use. Clean and prepare indoor growing area for fall transition.
September: Fall transition begins. Harvest basil heavily — make pesto, freeze leaves, dry herbs. Bring rosemary indoors when nights approach 35 degrees. Sow fresh cilantro and parsley for fall outdoor harvest. Spray perennial herbs with insecticidal soap before indoor move.
October: Transition to indoor growing. Move all perennial containers indoors before hard frost. Acclimatize gradually to indoor light levels. Pull spent basil and dill plants. Clean outdoor containers and store empty pots.
November: Indoor phase begins. Set grow light timers to 14 hours. Reduce watering frequency. Sow indoor basil and cilantro for winter harvest. Group herbs on pebble trays for humidity. Enjoy the last outdoor parsley and chives until hard freeze takes them.
December: Indoor phase. Steady-state maintenance. Water when soil dries. Harvest indoor basil and cilantro. Prune perennial herbs lightly to maintain shape. Appreciate fresh rosemary for holiday cooking — it is one of the genuine rewards of the year-round herb garden effort.
Frequently Asked Questions
Can I use a regular desk lamp as a grow light for herbs?
A regular incandescent or warm-LED desk lamp does not provide the spectrum or intensity that herbs need for active growth. Plants need light in the blue (400 to 500 nanometer) and red (600 to 700 nanometer) ranges for photosynthesis. Standard warm-white bulbs are heavy in yellow-orange light that looks bright to our eyes but provides limited photosynthetic energy. A purpose-built LED grow light costs 15 to 30 dollars and provides the correct spectrum at sufficient intensity. It is the single most worthwhile investment for winter herb growing.
How long will rosemary survive indoors over winter?
Rosemary can survive indoors for the full winter — November through March or longer — but it requires more attention than other herbs. It needs the most light (a south-facing window plus supplemental grow light is ideal), the best drainage (fast-draining soil mix, never sitting in a saucer of water), and good air circulation (stagnant humid air promotes powdery mildew). Keep temperatures cool — 60 to 65 degrees — if possible. Rosemary in a warm, dry, low-light room declines quickly. In the right conditions, it thrives indoors for months and emerges in spring ready for vigorous outdoor growth.
Is it worth growing herbs indoors if I do not have a south-facing window?
Yes, if you use a supplemental grow light. East and west-facing windows receive enough light for shade-tolerant herbs like parsley, chives, and mint but not enough for rosemary, thyme, or basil without supplemental lighting. A north-facing window is insufficient for any herb without grow lights. An inexpensive LED grow light panel solves the problem regardless of your window orientation. Positioned 6 to 12 inches above your herbs and running 14 hours per day, a single panel provides all the light your indoor herb garden needs, even in a windowless room.
Should I fertilize indoor herbs in winter?
Lightly. Herbs growing under reduced light in winter grow slowly and need less nutrition than outdoor herbs in peak summer growth. Fertilize once a month with a balanced liquid fertilizer at quarter strength. Over-fertilizing indoor herbs produces weak, leggy growth that is more susceptible to pests and disease. If you are using a grow light and herbs are growing actively, increase to half-strength every two weeks. Match the feeding rate to the growth rate — more light and more growth means more nutrition needed.
Can I take cuttings from outdoor herbs in fall to start fresh indoor plants?
Yes, and this is an excellent strategy for herbs that are too large or root-bound to bring indoors in their current containers. Take 4 to 6-inch stem cuttings from rosemary, thyme, sage, oregano, and mint in August or September. Strip the lower leaves, dip in rooting hormone, and stick in moist perlite or a peat-perlite mix. Cuttings root in 3 to 6 weeks. The rooted cuttings are compact, pest-free, and already acclimatized to indoor conditions by the time the outdoor season ends. They grow vigorously in small pots on a windowsill and give you fresh stock for the following outdoor season.