and I have an unspoken agreement: I provide care, it provides drama. This week the night temperatures dropped to 4°C (39°F) — far too cold for my chilli peppers, who’ve spent months basking in sun and showing off their glossy red coats. I couldn’t leave them out there, trembling in the wind like tiny lanterns on a freezing balcony. So, I did what any slightly obsessed gardener would do — I brought the spice indoors.
Now they’re lined up by the bedroom window, radiating color and attitude. The scent of soil and pepper fills the air. It feels a little wild, a little out of place — but also perfect. There’s something oddly comforting about sharing your space with your plants. Maybe it’s the reminder that we all need warmth to keep thriving. Perhaps tomorrow, when the sun rises and if the temperature allows, they’ll go back out. But for tonight, the rooftop’s loss is my bedroom’s gain. Here’s how to protect your rooftop garden from winter cold — and keep your plants thriving until spring.
Why Some Plants Need a Winter Refuge
Not all rooftop residents can handle the cold. Chillies, basil, and many tropical ornamentals are warmth lovers: once temperatures drop below 10°C (50°F), they start to sulk; below 5°C (41°F), they begin to die back. Rooftops exaggerate these extremes — heat by day, chill by night, and wind that cuts through everything. That’s why overwintering becomes essential: it’s a way of helping sensitive plants survive the off-season and restart stronger in spring. Before the cold season settles in — or even before bringing new plants home — take a quiet walk through your terrace to identify which plants are frost-tender and who stays outside.
Not all plants face winter equally — while hardy species actually benefit from the seasonal chill — it helps them rest and reset for spring; others suffer even before frost forms. Hardy herbs like rosemary, thyme, and sage, as well as shrubs, evergreens, and dormant fruit trees, as well as Mediterranean species, succulents adapted to poor soils, and most woody plants tolerate short cold spells if their roots are protected. These are your winter stayers — the quiet sentinels of the terrace. The rest — tender types like chillies, basil, mint, or tropical ornamentals — should be moved to shelter before the first real cold night arrives.
Rooftop Overwintering Ideas
=Bring them indoors=
Small pots — like chilli peppers, herbs, or young citrus trees — adapt well to a sunny window once the nights turn cold. But light isn’t everything; temperature near the glass can drop sharply, especially overnight. Leaves that touch cold windows can develop damage that looks like burns, even though it’s actually cold scald.
To prevent this, keep a small gap between the plants and the window, or line the inside of the glass with clear bubble wrap or a piece of greenhouse plastic sheet. Both options act as insulation while still letting in plenty of light. Avoid placing pots too close to heaters or radiators, since dry indoor air can stress them just as much as cold drafts. The goal is to create a pocket of gentle, stable warmth — enough to keep your plants resting comfortably through winter. Water sparingly, about once a week; most plants nap through the colder months, and excess care is usually more dangerous than neglect.
=Use sheltered corners=
If you can’t bring everything inside, gather your pots against a south-facing wall, as far from the cold wind as possible. Grouping plants close together helps create a small pocket of warmer air — each pot shares a little of its stored heat with the next. But just as important as protection from wind is having something above them.
Even a light structural cover, such as a pergola, balcony edge, greenhouse shelf, or improvised canopy, makes a huge difference. Plants under a roof or ledge lose less heat to the open night sky, which acts like a giant cold sink. This small barrier keeps frost from forming directly on the leaves and reduces the sharp temperature drops that stress tender plants. It doesn’t need to be airtight — just enough to break that open-sky exposure. If you’ve noticed that the plants with a bit of overhead protection look healthier in the morning, that’s not your imagination — they’re literally sleeping under a warmer blanket.
=Add a mini greenhouse=
Those small tiered greenhouses or transparent covers are perfect for rooftops. They don’t generate heat, but they buffer your plants from early morning cold and drafts — acting like a gentle windbreaker. They’re especially useful for chillies, tomatoes, or seedlings you’re trying to overwinter. Just remember to open them on sunny days to avoid condensation build-up.
=Frost covers=
These work like a cozy blanket, keeping out the wind chill and trapping just enough warmth to soften the night air around your plants. They don’t heat the space, but they buffer it, reducing the sudden temperature swings that cause most cold damage. These light, breathable covers also prevent moisture from settling on leaves and turning into frost crystals at dawn. It’s a simple, gentle layer of protection that can make the difference between a plant that struggles and one that greets spring still green and ready to grow. If you don’t want the cover to touch the tender top leaves you can place stakes in the pots and have the frost cover supported by them.
=Wrap roots =
Cold kills from the roots up. Wrap pots with bubble wrap, jute, or even old towels to insulate them. Another option is to keep the pot’s base off the cold floor — using wooden pallets or cork bases helps keep the pots warmer. Nesting one pot inside another creates a simple air barrier that keeps warmth in longer, especially if you fill the gap with straw, leaves, or even bubble wrap. Add a layer of mulch on top, and you’ve given your plants a miniature fortress against the cold.
=Wrap Trees=
Even on a rooftop, trees feel the full force of winter — cold air from all sides, strong wind gusts, and temperature swings between day and night. Young or tender species like peach, fig, persimmon, pomegranate, or young walnut are especially vulnerable. Their bark can split or scar when sudden temperature drops cause the outer layers to contract faster than the inner wood — a phenomenon known as frost cracking or sunscald. Wrapping their trunks with burlap, jute, or breathable tree wrap helps buffer these shocks and keeps the bark from drying or splitting. It’s not about adding heat — it’s about preventing extreme change. For small potted trees, wrapping the pot and lower trunk together adds another layer of protection. Figs, persimmons, and pomegranates are tougher, but even they benefit from a simple windbreak or a temporary cover during the coldest nights. A few minutes spent wrapping now can spare months of recovery later.
=Cut back on kindness=
For both indoor and outdoor plants, avoid fertilizing and water only sparingly. Most plants slow down in winter and don’t need constant care — too much attention leads to soggy soil and, eventually, root rot. Early signs of root rot often go unnoticed until it’s too late. The first clue is usually the smell — a faint sour or earthy odor when you water the plant. Then come soft, limp stems or leaves that yellow from the base up, even though the soil still feels damp. In pots, the roots may start to turn dark and mushy instead of firm and white.
If you notice any of these, pause watering immediately and let the soil dry completely. Check that drainage holes aren’t blocked and, if needed, repot into fresh, well-draining mix after trimming any blackened roots. Misting leaves occasionally helps maintain humidity indoors — and it also keeps spider mites from settling in during the dry months. Just avoid spraying so much that water drips into the soil. In winter, restraint is the best form of care; sometimes loving your plants means giving them space to rest.
=Mulch=
We aren’t the only ones who appreciate an extra blanket when winter arrives. On a rooftop, where cold air circulates freely and pots lose heat quickly, mulch acts as insulation for the roots — the most vulnerable part of any plant. A layer of straw, pine needles, or shredded bark around the base of your perennials helps stabilize soil temperature and slows water evaporation. It’s especially useful for woody herbs, roses, and potted fruit trees, which can suffer when roots freeze and thaw repeatedly.
Aim for about four to six centimeters (around two inches) of mulch — a little less than in-ground gardens — and keep it slightly away from the stem to prevent rot. We’re protecting roots, not smothering them. Beyond warmth, mulch also keeps the rooftop cleaner, preventing soil from splashing out of pots during heavy winter rain. Think of it as a soft winter quilt that helps your garden rest comfortably until spring.
Other tasks
=Check the Rooftop Drainage=
Before winter rains arrive, it’s worth giving your rooftop drainage system a proper inspection. A single clogged outlet can quickly turn your terrace into an unintended pond, soaking pots, roots, and sometimes even your patience. Start by removing fallen leaves, soil, and plant debris from the drainage area — they tend to collect unnoticed behind pots or corners where wind deposits them. If your drain has a protective grate, lift and clean it regularly, checking that water flows freely underneath.
Installing a fine mesh or leaf guard helps stop small particles from slipping through and forming blockages deeper in the pipe. During heavy rain, watch how water moves across the rooftop; any puddling is a sign that something’s slowing the flow. A few minutes of maintenance now can prevent the kind of overflow that leaves your plants sitting in cold, stagnant water — or worse, gives you a rooftop swimming pool you never asked for.
=Clean plants and tools=
Before the cold arrives, give your plants and tools a good seasonal clean-up. Remove any dead leaves, fallen petals, and spoiled fruits — but resist the temptation to toss them into the compost pile if they show signs of disease or pest damage. It’s better to discard them separately to avoid carrying problems into next season’s soil. Wash and disinfect pots, saucers, and garden utensils before storing them — a quick scrub with soapy water or vinegar goes a long way. It’s also the perfect moment to organize supplies, sharpen pruners, and check ropes, ties, and stakes for wear. A tidy, clean rooftop garden weathers the winter better — and greets spring ready to grow again.
Final Thought
The rooftop has taught me that survival isn’t always about endurance — sometimes it’s about knowing when to retreat. “How I Brought Spice into the Bedroom” shares my strategy for protecting rooftop plants during winter.
What are your strategies for keeping your plants alive during the winter? Share, I’d love to know.
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