Hardy plants are a must-have in any outdoor space. The right plants in the right place can help make a garden low maintenance, attract wildlife, add winter interest, create privacy or grow your own food. Here are our top picks, from pretty annual flowers to hard-working, long-lasting evergreens, all hardy to at least -15C. What is a hardy plant?
The term ‘hardy’ refers to cold tolerance. A hardy plant is tough and resilient – even though it may not look it – and can survive winter’s challenging conditions.
Atop tall wiry stems, delicate feathery flowers in pinks, blues and purples are a favourite of bees. These annual plants only live for a year, but their hardiness means they can be sown outdoors in early spring as the seedlings won’t be affected by frosts. Simple to grow from seed, they’re great for pots and prefer full sun.
Hawthorn’s bright green leaves unfurling is one of the first signs of spring, bringing a dash of early colour to woods, hedges and gardens around February. An explosion of pretty white blossom makes for a dazzling display in May, followed by deep-red haw fruits loved by birds. Great for hedging or as a standalone specimen tree, hawthorn is hardy to -20C and will grow in most locations as long as soil isn’t waterlogged.
The versatile foxglove is a cottage garden staple that’s often found on verges and in woodland too. Tall, majestic spikes of purple-pink tubular flowers are a showstopper from June to September. Happy in shade, foxgloves don’t like extreme wet or dry conditions but will otherwise grow in most soils. As a biennial it has a two year life cycle, but self-seeds readily so once established, you’ll have beautiful borders for years to come.
Crab apple is a spring stunner. With some of the prettiest blossoms around, it’s worth growing for its sweet-scented pink and white flowers alone. Drought tolerant and growing to 10 metres, it’s a good choice for small gardens. Like other native trees, it’s a magnet for wildlife and will grow in most soils and aspects. Crab apple is an ancestor of the cultivated apple and while its small fruits are too tart for the average palate, they cook up into a scrumptious crab apple jelly or liqueur.
Hardy plants are a gardener’s best friend. These tough, resilient plants can withstand cold temperatures, harsh weather, and poor soil conditions. But what exactly makes a plant hardy? In this comprehensive guide, we’ll explore what hardiness means, how it’s measured, what makes plants hardy, and tips for choosing and caring for hardy plants.
What is Plant Hardiness?
In simple terms plant hardiness refers to a plant’s ability to survive cold winter temperatures. The hardier a plant, the lower the temperatures it can withstand.
Hardiness is an important factor when choosing plants, as it determines which plants will thrive in your climate. The United States Department of Agriculture (USDA) has developed a plant hardiness zone map that divides the country into different zones based on average minimum winter temperatures.
This map serves as a guide to help gardeners understand which plants are most suitable for their zone. For example, if you live in zone 5 where temperatures can drop to -10 to -20°F, you’ll want to choose plants rated hardy to at least zone 5 or lower.
How is Plant Hardiness Measured?
There are a few different systems used to measure plant hardiness
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USDA Hardiness Zones: As mentioned above, this is the most commonly used system in the U.S. It divides the country into 13 zones based on average winter lows. Zone 1 is the coldest at -60°F and below, while zone 13 is the warmest at 60-70°F.
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Sunset Climate Zones: Popular in the western U.S., this system incorporates temperature, humidity, precipitation, and other factors. It uses a scale of 1-24.
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American Horticultural Society (AHS) Heat Zones: Ranging from 1-12, this measures heat tolerance and is used in conjunction with the USDA hardiness zones.
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Royal Horticultural Society (RHS) Ratings: Used in the UK, this system has ratings from H1a to H7, with H7 being the most cold hardy.
What Makes a Plant Hardy?
Plants have developed some remarkable adaptations that allow them to survive freezing temperatures. Here are some of the ways they achieve hardiness:
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Supercooling: Some plants can avoid freezing by lowering the temperature at which water inside their cells turns to ice.
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Extra Insulation: Certain plants grow thicker leaves, bark or cell walls to prevent freezing.
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Transferring Water: Plants can move water from cells into intercellular spaces, so it freezes there instead of inside the cells.
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Shedding Leaves: By dropping their leaves, some plants avoid damage from desiccation or wind chill.
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Going Dormant: Many hardy perennials die back to the ground in winter, surviving via hardy roots or crowns safely below the frost line.
Hardy plants also tend to have extensive root systems, thick cuticles to reduce water loss, and the ability to withstand drought, heat, wind, and poor soils. These tough constitutions allow them to thrive in challenging climates.
Tips for Choosing Hardy Plants
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Check your hardiness zone: Choose plants rated for your zone or at least one zone colder.
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Consider microclimates: Sheltered spots may allow you to stretch the zones. Avoid frost pockets.
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Select native plants: Plants native to your region are adapted to local conditions.
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Favor perennials: Hardy perennials are resilient and return each year.
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Look for indicators: Smaller leaves, fuzzy or waxy foliage and compact shape often indicate hardiness.
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Read labels carefully: Terms like “hardy,” “frost hardy,” or zone numbers offer clues.
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Research unknown plants: If needed, look up a plant’s native range and habitat.
Caring for Hardy Plants
While hardy plants are low maintenance, providing a bit of extra care will help them thrive:
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Water thoroughly: Give deep waterings during droughts so roots access moisture.
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Use mulch: A 2-3 inch organic mulch insulates plant roots from temperature extremes.
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Prune judiciously: Most pruning should be done in late winter to avoid cold damage.
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Provide wind barriers: Use fencing, shrubs or burlap to block desiccating winds.
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Improve drainage: Amend soil with compost to prevent waterlogging in winter.
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Allow self-seeding: Many hardy plants naturally self-seed for reliable returns each year.
Hardy plants form the backbone of low-maintenance, resilient gardens. Understanding exactly what hardiness means, how it varies by climate, and what adaptations plants use to survive will help you make informed choices. Consider each plant’s unique needs, provide winter protection where required, and your hardy plants will reward you with years of beauty and abundant returns.
(Hedera helix, Hedera hibernica)
This evergreen climbing shrub gives dense leafy cover year-round, offering valuable shelter for wildlife. Ivy supports at least 50 species and is one of the last garden nectar sources for late-flying insects. Its low maintenance, can survive in most soils and is perfect for a shady spot. Different varieties boast leaves in many shapes and shades, and contrary to popular belief, it’s safe to grow on walls as long as the masonry is sound. It can even help cool your home in the hot summer months.
Credit: Nigel Bean / naturepl.com
This deciduous shrub is a popular choice for its welcome burst of winter colour. Through spring and summer, clusters of creamy white flowers develop into small black berries that attract insects and birds. The vivid green leaves fade to a rich red before falling in autumn to reveal fantastic crimson and orange winter stems. Dogwood will grow in many soil types, including damp conditions. Prune to retain size and shape and cut back hard each year to keep stems bright.
Credit: Liz Pearson / WTML
One of the first plants to bloom in spring, wood anemone’s delicate star-shaped flowers are white tinged with pink. It’s a shade-loving plant, often found in swathes across a woodland floor from March to May. Due to its small size, it’s suitable for pots and containers as well as beds and borders – flowers are about 2-3cm wide and 15cm high over a rosette of green leaves. Other varieties are available in many colours. They arent all hardy like our native, but are all perennial, dying back after flowering to regrow the following spring.
Whether you need a screen, hedge or centrepiece, we have beautiful native trees to give your garden interest all year round. Delivery is free.
What is a hardy plant?
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