Gardens Illustrated
Gardens Illustrated picks out garden furniture, tools and lifestyle items that we think are the best and most exciting, based on independent research and careful consideration. On some occasions we earn revenue if you click the links and buy the products. But this doesn’t affect what we choose to highlight and we will never let it bias our coverage.

Eco-friendly plant protection for winter

Published: November 24, 2021 at 2:21 pm

How do you keep your plants safe and warm if plastics are no longer an option? Our pick of sustainable and ecologically sound protection options will do the job all winter long

Every year we've the same worry: how do we best protect our precious plants from damage caused by low temperatures, frost, ice and snow?

Advertisement

Much of the widely-available plant protection equipment available is, however, made of plastic, and could not be considered eco-friendly. So here we have rounded up all the ways you can both protect your plants and protect the environment, with smart and sustainable ideas and products to try.

If sustainability and eco-credentials are not such a priority for you, read our guide to other winter plant protection products.

Why do I need to protect plants in winter?

Many of the best and most popular garden plants are hardy, and therefore perfectly able to withstand cold snaps, but there are other shrubs and perennials that are more sensitive – often called half-hardy or tender plants. These beauties, which often hail from warmer climates around the world, need all the help they can get to survive the freezing conditions and winter wet.

And as winter turns to early spring, and you begin to sow seeds and propagate plants, you also need to consider garden protection for seedlings and young plants, whether you are hardening them off before planting them out in the ground, or simply offering cover for direct sown seedlings.

There are of course multiple ways to do this, ranging from quick and affordable to easy luxury. And all are proven sustainable and eco-sound.

Eco alternatives to garden fleece

Pittosporum tenuifolium ‘Tom Thumb’
Pittosporum tenuifolium ‘Tom Thumb’ © Jason Ingram

There are some borderline plants, such as Pittosporum and Callistemon, that are hardy enough to grow outdoors year-round and can typically withstand a mild winter with spells of light frost, but will need some help temporarily if very cold temperatures are forecast, or in gardens in exposed areas. This is where horticultural fleece, also called garden fleece, comes in handy, as it can be wrapped around the plant as and when needed for protection when you know a freeze is coming.

For the eco-friendly gardener, however, horticultural fleece is a fraught choice, as it is made from polypropylene or polyester - synthetic materials – and tends to shred and break down with exposure to the elements. Although it is soft and warm, like fabric material, it can be considered a single-use or short-term plastic product.

So what to choose instead?

Agralan Envirotect

Envirotect is endorsed by the RHS, and is a more sustainable alternative to lightweight garden fleece, as it is made to be more durable and long lasting, meaning you can use it again and again, year after year. Made from UV-stabilised polyethylene, it looks like netting and can withstand harsher conditions, can be washed in the washing machine on a wool cycle, and is also recyclable. Thick and heavier than fleece, it is less likely to rip or blow away.

Agralan Heavy Duty 30g Envirofleece Winter Weight Fleece Frost Protection

This heavier weight option is longer lasting than typical lightweight fleece, and provides enhanced frost protection for less-hardy plants and shrubs as well as tender young plants. It will also protect early potatoes right down to -6ºC. Plus it can be used as an effective and economical greenhouse insulation to minimise condensation, and placed temporarily over plants on the ground or laid over tunnel frames for protection.

How to protect pots and containers over winter

Butternut squash
© Andrew Montgomery

Plants growing in pots are more prone to damage than those growing in the ground, as they are more exposed – garden soil offers better insulation to those delicate roots than a container can. The best way to protect the roots from freezing, and to protect your pots that are not frostproof, is to wrap them in some sort of protective material. This is necessary because pots made from natural materials like terracotta take in moisture, which then freezes in the cold, and causes the pot to crack and shatter. To avoid this you can buy frostproof pots or simply wrap the ones you have in protective material.

Bubble wrap is often recommended, but there are eco-friendly alternatives available. They include products made from sheep’s wool, from felty fabric to thick mats, which can be tied in place around pots, planters and containers to offer that extra layer of protection. Another option is coconut fibre matting, which can be used in the same way and placed around the base of potted plants too.

Windhager Sheep's Wool felt pad

This is a strong, natural matting made from hard-needled skeepskin felt which, when wrapped around pots and plants will protect them from cold, wind and frost. It's a completely renewable raw material which is breathable and exhibits excellent capacity for retaining heat – not surprising considering at it's essentially sheeps wool in a more resistant, hard-wearing form.

Its resilience ensures that air pockets remain trapped between the fibres, giving an excellent barrier to prevent heat loss.

Buy the sheep's wool felt pad from Windhager

Manufactum Sheep’s Wool Frost Protection Fleece

Another 100% natural alternative to plastic derived fleece and matting. This alternative fleece is again made from sheep’s wool, being a rougher bi-product of wool used for clothing. Once again it's perfect for protecting pots and young plants from wind, cooler weather and nocturnal frost. Wrap containers, cover your plants in their bed overnight or wrap around plants exposed to wind and prone to frost when cold temperatures are forecast. Make sure to remove from plants in the ground during the day when it is warmer to aid airflow.

Manufactum Sheep’s Wool Protective Winter Matting

Perfect for wrapping around containers and pots where a lack of space or other protection means that your planters and plants have to remain exposed, such as on a balcony or in a small back yard, or for large heavy pots in bigger garden that can't be moved indoors. This robust matting is made from dyed sheep’s wool felt, exhibiting all the natural warming benefits of sheeps wool. Wrap the pots to protect the plant's roots from freezing and also to prevent the pot itself from cracking.

Manufactum Coconut Fibre Mat

Coconut matting

While not as immediately 'warming' as wool-based options, coconut fibre can be just as effective and is even more hard-wearing. And, thanks to being water resistant, can be placed in direct contact with the soil, allowing water to pass through unhindered without rotting away or disintegrating, which will eventually happen with other natural alternatives to fleece. A layer of coconut fibre carefully cut and wrapped around your pot and also, if you wish, cut out to cover around the base of the plant will protect your pot and your plant's roots.

How to protect tender garden plants from frost

We've protected our pots and larger plants, but what about more delicate and tender plants?

Frost in The Dry Garden in winter at RHS Garden Hyde Hall.
Frost in The Dry Garden in winter at RHS Garden Hyde Hall.

Large, tender plants such as bananas and tree ferns, and borderline hardy exotic plants like Tetrapanax, are usually grown in the ground year-round in milder UK gardens because of their bigger size and growing needs, but as a result, they really need extra winter protection. These plants should have their crowns and trunks packed carefully with dry natural insulation and then wrapped in a fleece alternative like those mentioned above, or hessian.

The best way to do this is to construct a frame around the plant with bamboo canes or chicken wire, before stuffing gently with straw or bracken, and then tying the fabric on around the outside with twine. This approach also works well for less-hardy climbing plants such as passion flower.

Jute Hessian Frost Protection and Rootballing Fabric

Natural jute hessian, also known as burlap, is a good frost protection fabric for wrapping larger borderline hardy and tender shrubs like Musa and Ensete or Dicksonia. It's completely natural, but very strong and tough. It allows water and air to pass through, and at the end of its useful lifespan is completely biodegradable.

Open weave hessian fabrics such as this one are ideal for frost protection as part of frame system with, for example, bamboo canes and an inner lining of straw. Hessian is also often used for covering the rootballs of trees and shrubs when transplanting them.

Using mulch for winter protection

Lots of deciduous perennials, which die back over winter but reappear each spring with fresh growth, need some extra insulation and frost protection for their root systems over winter. Mulching is simply adding a layer of organic material on top of the plant. Add your chosen mulch around it to a depth of 5cm, making sure to keep some space around the stems at the base.

Garden Solutions Special Winter Mulch

This Special Winter Mulch is an ideal end of season top up that you can quickly and easily apply to the top of your soil and it will help strengthen the root structure of plants and shrubs during winter, leading to less damage. Of course, adding this extra layer also increases soil cover and insulation and the increased heat boosts microbial activity and gives a higher survival rate of worm eggs which will helps with the breakdown of organic matter for the following season.

Apply before the end of December for the best results and before the severe frost hits.

Earthcycle Winter Mulch

If you need mulch in bulk then a large 1000kg bag from Earthcycle is a great option for getting the job done fast. Earth Cycle Winter Mulch benefits all kinds of soils over the winter period and can even lighten heavy clay soils to make them more workable when worked into the top 15cm of soil. Apply a consistent layer to your beds and borders to insulate the soil below while its nutrients will look after and feed your veg and fruit planting such as tomatoes or strawberries all year round.

SylvaBark pine mini mulch

Sylva bark mini mulch

This simple to apply dry mulch is made with British pine bark from sustainably sourced from FSC-certified forests, and is ideal for mulching individual pots and using around plants that like a drier soil around them in winter, such as Mediterranean sub-shrubs and woody perennials, and borderline hardy bulbs, tubers and rhizomes such as dahlias (should you be brave enough to leave them in the soil overwinter). As well as insulating the ground around the plant against frost, like many of these mulches, it also wins points for suppressing weeds. It's got an effective lifespan of at least two years, over which time it will break down and contribute to improving your soil's structure.

Strulch

Here's an alternative eco product that's well worth a look. Strulch is a mineralised straw mulch that's easy to apply as an alternative to bark or soil-based products, and lasts up to two years. It will offer a level of protection for your plants' roots over winter when used widely across beds and borders, doing a good job of enriching the soil and suppressing weeds, while helping to retain moisture in warmer seasons. And – thanks to its rough texture – it also helps to keep slugs and snails at bay.

How to cover plants with garden cloches

If your less-hardy plants are not growing in containers or pots, but instead need extra cover while growing in the ground, you can bring the protection to them with a garden cloche. Popular in Victorian kitchen gardens, cloches are having a revival, being an easily portable solution that you can move to cover the exact plant you want to protect, exactly when you want to. They are especially suitable for young vegetable seedlings, such as peas and beans, when they are first planted out; or to keep salad leaves and herbs growing happily further into autumn at the end of the growing season.

Although thin plastic versions are available, they won’t win any points for sustainability, but there are a multitude of glass cloches available, which also add a touch of class to your plot.

Styles range from bell jar shapes to lantern-type forms with a metal frame, and in various sizes.

Suttons Bell Glass Cloches

These are based on the classic shape and available in small, medium or large sizes, or buy all three as a set. Small: 20 x 20 x 20cm; Medium: 25 x 25 x 25cm; Large: 30 x 30 x 30cm. These sturdy domes will keep your baby plants warm and cosy, but on sunny days make sure to remove for a short period or prop the edge up for a while to allow cooler air to circulate around the plant.

RHS Ventilating Cloche

  • Buy now from RHS (£29.99)

A ventilating cloche allows you to stay versatile and manage the vagaries of the weather more easily with a hole in the top of the glass jar, and a green glass stopper for it, which can be removed on warm days or popped in when it is cold. W24cm x H33cm.

Move plants in pots into a greenhouse for winter

If you're really serious about plant protection then there's nothing better than a safe, warm place under glass you can relocate them to. A glasshouse or greenhouse is invaluable at this time of year, as you can move tender and half-hardy plants in pots, from pelargoniums to citrus and cannas, to frost-free safety undercover. Spending a considerable sum on a glasshouse is all too easy, but there are quality greenhouses available to suit every budget.

Forest Garden Victorian Walkaround Greenhouse

forest garden walk around greenhouse, best greenhouses, best victorian greenhouse
Garden Chic

Take this Victorian greenhouse in miniature for example. Designed with four opening doors in natural timber and styrene glazing, it provides walk-around access from all sides.

Features like its apex roof are in keeping with traditional greenhouses. Its 989mm x 1239mm footprint means it's also small enough to stand in small gardens where space is a premium, without being too intrusive.

Slatted staging is removable and offers room enough for two grow bag trays and its single large vent can also be opened to encourage airflow.

For even more fabulous options, check out our choice of other stylish luxury glasshouses. But if you don’t have the space or budget for a full-size model, there are countless smaller, more affordable mini greenhouses to suit your space. The principle remains the same no matter how much you spend.

Halls Wall Garden Mini Greenhouse

Halls mini greenhouse
Garden Chic

The slim frame of this aluminium finish small greenhouse means that plants within get almost unobstructed sunlight without having to withstand wind.

The shelving is optional, which is good if flexibility is something you’re looking for when it comes to a mini greenhouse. There's also a roof vent for climate control.

For more options, take a look at our top selection of mini greenhouses.

Cold frames: the more compact (and affordable) way to protect plants

For smaller plants, smaller spaces or a smaller budget, you can still take advantage of growing under glass without breaking the bank. Go for a eco-conscious cold frame made from FSC-certified wood with glazed panels. Just like a greenhouse, cold frames create a warmer climate thanks to their insulated situation under glass, retaining solar heat and keeping tender plants safe from sharp frosts and strong winds.

A good-quality cold frame made from long-lasting, sustainable materials will last for many years and can be used to extend the growing season for late season crops, as well as give you the opportunity to start sowing earlier than usual, and protect cuttings and frost-tender seedlings until you can plant them out in the soil, after all risk of frost has passed in late spring.

Zest4Leisure Sleeper Cold Frame from Robert Dyas

This unit is made from responsibly sourced timber and comes flat-packed for self-assembly with fixings and instructions. The wood is pressure treated to ensure it lasts longer. This unit is of sturdy construction and a good size at H43 x W170 x D60cm, with a side arm to prop open the glazed lid on warmer days.

The Gabriel Ash Baby Grand Coldframe

Advertisement

This is a beautifully made, top-end choice that comes with a 10-year structural guarantee. It is made of western red cedar, with robust stainless steel and brass fixtures and fittings, 3mm toughened safety glass glazing panels and rust-proof powder-coated aluminium plinth and cappings, so is sure to be a useful and attractive feature in your garden well into the future. Made to order, it arrives flat-packed for easy self-assembly.

Authors

Stephanie Mahon, Editor of Gardens Illustrated
Stephanie MahonEditor, Gardens Illustrated

Stephanie Mahon is an editor and writer on garden and landscape design. Twice winner of the Garden Media Guild Journalist of the Year Award, she is presently writing a book on wild gardens.

Advertisement
Advertisement
Advertisement

Sponsored content