How can you tell if a plant will survive in cold weather? It’s sad to see your favorite plants die in the winter, even though frosty mornings are pretty. But if you know how plant hardiness ratings work, you can make sure your plants are safe through the winter.
A hardy plant is one that can withstand cold winter temperatures and other challenging environmental conditions. Hardy plants have adapted to survive freezing temperatures, drought, poor soil, disease, and pests. Knowing what makes a plant hardy can help you choose the right ones for your landscape.
What Makes a Plant Hardy?
There are a few key factors that contribute to a plant’s hardiness:
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Cold tolerance – Hardy plants can handle freezing temperatures without damage. Many hardy plants go dormant in winter allowing them to survive the cold.
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Heat tolerance – Hardy plants can thrive in hot summers and heat waves. They are less prone to heat stress.
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Drought tolerance – Hardy plants need less frequent watering Their root systems can access water deep in the soil. Many have thick leaves or stems that retain moisture
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Disease resistance – Hardy plants have natural defenses against common plant diseases This prevents issues like powdery mildew and root rot
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Pest resistance – Hardy plants can ward off insects, animals, and other pests without damage. Some have thorns, unappealing foliage, or toxins.
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Vigor – Hardy plants grow vigorously. Their rapid growth helps them recover quickly from damage.
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Adaptability – Hardy plants easily adapt to various soils, sunlight, moisture levels, and climates. They thrive in diverse environments.
Examples of Hardy Plants
Many popular landscape plants are considered hardy in certain growing zones. Some examples include:
- Ornamental grasses like fountain grass, pampas grass, and miscanthus
- Coneflowers, black-eyed Susans, and coreopsis – tough perennial flowers
- Yucca, lavender, sage – drought-tolerant herbs
- Boxwood, spirea, potentilla – hardy shrubs
- Maple, oak, birch – deciduous trees
- Arborvitae, juniper – hardy evergreen trees and shrubs
- Daylilies, iris, peonies – hardy perennial flowers
Growing Hardy Plants
Here are some tips for growing hardy plants successfully:
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Select plants suited to your climate. Choose species rated for your USDA plant hardiness zone.
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Prepare the soil well. Hardy plants thrive in nutrient-rich, well-draining soil. Add compost or other organic matter when planting.
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Allow enough space. Give hardy plants room to reach their mature sizes. Follow spacing guidelines.
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Water thoroughly. Water deeply and infrequently once established. Avoid frequent shallow watering.
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Use mulch. Apply 2-4 inches of mulch to insulate plant roots and conserve moisture. Replenish annually.
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Fertilize lightly. Hardy plants rarely need heavy feeding. Apply a balanced fertilizer in early spring or as needed.
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Remove spent flowers. Deadheading flowers encourages more blooms on hardy perennials.
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Trim sparingly. Avoid heavy shearing or pruning of hardy plants when possible.
With proper selection and care, hardy plants can thrive for years in your garden. Their vigor and resilience makes them ideal choices that require less maintenance and can handle challenging conditions.
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How to protect plants in winter
Many plants will need some protection to get them safely through the cold months. Here are a few tips on how to protect your plants in winter.
- Put pots on pot feet to keep the compost from getting too wet. If you plant hardy plants in pots that don’t drain well and freeze in the winter, even those plants may die.
- Because plant roots are more likely to get cold in pots, it’s a good idea to insulate pots with fleece or bubble wrap when you live in cold places.
- To keep plants safe from frost, bring them inside and put them in a greenhouse or conservatory.
- In mild areas, cover the ground with a thick layer of organic mulch, like compost or straw, to keep dahlia and begonia tubers safe.
Visit our center to see our great selection of hardy plants if you want plants that can handle winter weather. Our staff will be happy to help you!.
What does hardiness mean?
Hardiness measures a plant’s ability to stand cold winter temperatures in the gardening world. A hardiness rating system created by the Royal Horticultural Society sorts plants into groups based on the coldest temperature they can handle. This scale goes from H7 (for plants that can live in temperatures below -20°C/-4°F) to H1a (for plants that need to be kept above 15°C/59°F).
It’s helpful to know some of the other terms used to describe hardiness and how they relate to the RHS definitions because not all plant websites or labels use the RHS ratings.
- Tender: These plants can’t live in temperatures below 0°C/32°F, so they need to be kept inside during the winter. In the summer, they might be able to go outside. On the RHS hardiness rating table, these are the same as levels H1a, H1b, H1c, and H2.
- Most of the time, these plants can handle short periods of temperatures as low as -5°C/23°F. They can spend the winter outside in mild places, but they will need to be protected in colder places or during hard winters. Level H3 on the RHS hardiness rating table is for half-hardy plants.
- Fully hardy means that these plants can live in temperatures as low as -10°C/14°F. They are the same as levels H4–H7 on the RHS hardiness rating table.
Note: A plant’s hardiness level tells you the coldest temperature it can survive, but you should also think about other things. One of the most important is soil drainage. If the soil is too wet, even a hardy plant can die in the winter. On the other hand, a borderline hardy plant is more likely to make it through a cold snap if the soil drains well.
What is a hardy plant?
FAQ
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