WTF does ‘hardy’ mean?

Welcome to my WTF Gardening series, where I take common gardening terms and explain them for those who are new to the world of plants. Find the entire WTF Gardening series here.

In the world of gardening, there are many different terms that are used to describe plants. One of the most common terms is “hardy.” But what does it mean for a plant to be hardy? And why is it important to know when choosing plants for your garden?

In this article, I’ll explore what it means for a plant to be hardy, and give seven examples of hardy plants. 

What Does It Mean for a Plant to Be Hardy?

A hardy plant is one that can withstand low temperatures. Hardy plants are typically well-adapted to their local climate, so while a hardy plant might be able to survive a UK winter (one which rarely goes below -10C), it would probably die if you plonked it in the middle of Antarctica. 

The subcategories of hardy plants

When buying hardy plants, look closely at the label to understand what kind of plant they are, or do your research before buying, so that you know what to expect of the plant while growing it. The subcategories of ‘hardy’ are:

• Hardy perennial – a plant that can survive low temperatures and come back after dormancy for several years. For example, camellias and hostas.
• Half-hardy perennial – a plant that will come back year after year, but needs to be protected or brought inside during the winter. For example, fuchsias and pelargoniums.
• Hardy biennial – a plant usually lasting for two years that will grow strong roots and leaves in its first year, then go to seed and die in its second year, surviving the winter in between. For example, foxgloves and aquilegia.
• Hardy annual – these plants go through an entire life cycle in one season. They can withstand lower temperatures, and can be sown straight into the garden in spring where they will flower. For example, poppies and salvia.
• Half-hardy annual – these plants cannot survive cold and wet winter weather. They will die if exposed to frost. When starting half-hardy annual plant seeds, you need to place them in a warm environment, then they can later be planted outside after the last frost. For example, cosmos and zinnias.

USDA and RHS hardiness zones

A plant hardiness zone is a geographically defined area in which a specific category of plant life is capable of growing year-round without the need for special protection. 

The United States Department of Agriculture (USDA) developed the original hardiness zone system in 1960, and it has been updated several times since then. According to Gardenia, the UK lies in hardiness zones six to nine.

The USDA hardiness zone map is a useful tool for gardeners because it can help them choose plants that are likely to survive in their particular climate. For example, a gardener in Zone 5 would not want to plant a tropical plant that is only hardy to Zone 10, because it would likely die in the winter.

The Royal Horticultural Society (RHS) uses a different hardiness zone system than the USDA, which consists of a combination of numbers and letters as the hardiness rating (H1a through to H7), and was introduced in 2012. All plants in the RHS Award of Garden Merit (AGM) lists are given hardiness ratings, and the lists are regularly updated.

It is important to check the hardiness zone system that is used in your area before planting any new plants. It is also important to note that any hardiness zone map is just a general guideline. There are many factors that can affect the hardiness of a plant, such as the microclimate of the area, the amount of sunlight the plant receives, and the amount of water it gets. Therefore, it is always a good idea to consult with a local nursery or garden centre before planting a new plant.

Why Choose Hardy Plants?

There are several reasons why you might choose hardy plants for your garden. 

First, hardy perennials and biennials are less likely to die from exposure to harsh weather conditions. This can save you money in the long run, as you will not have to replace dead plants as often. You also won’t have to spend time lifting plants and use up space inside your home to store them over winter.

Second, hardy plants are often easier to care for than those that are less hardy. This is because they are usually more tolerant of their typical environmental conditions.

Third, there are a wide range of hardy plants available from garden centres, nurseries and online. You won’t struggle to find them! Plus, you can grow many hardy plants yourself from seed, making the process even more rewarding.

7 Examples of Hardy Plants

Now that we know what it means for a plant to be hardy, let’s take a look at seven examples of hardy plants.

 

Rose of Sharon (Hibiscus Syriacus): The Rose of Sharon is a beautiful shrub that is native to Asia. It is hardy in zones 5-9 (RHS H5), and it can grow up to 10 feet tall. Rose of Sharon has fragrant flowers that bloom in the summer, and it is a popular choice for landscaping.

 

Daylily: The daylily is a perennial flower that is native to Asia and Europe. It is hardy in zones 3-9 (RHS H6), and it comes in a variety of colours and sizes. Daylilies are easy to care for, and will spread.

 

Hosta: The hosta is a perennial plant that is native to Asia. It is hardy in zones 3-9 (RHS H7), and it comes in a variety of colours and sizes. Hostas are great for shady areas of the garden.

 

Yarrow: The yarrow is a perennial plant that is native to Europe and Asia. It is hardy in zones 3-9 (RHS H7), and it comes in a variety of colours. Yarrow is a drought-tolerant plant, and it makes a great addition to any xeriscape garden.

 

Sage: The sage is a perennial plant that is native to Europe and Asia. It is hardy in zones 5-9 (RHS 5). Sage is a drought-tolerant plant, and is a complement to any herb garden.

 

Lavender: The lavender is a perennial plant that is native to the Mediterranean region. It is hardy in zones 5-9 (RHS H5), and is known for its indigo blooms. Lavender is a drought-tolerant plant, and is attractive to pollinators.

 

Rose: The rose is a perennial plant that is native to Europe. It is hardy in zones 5-9 (RHS H6), and it comes in a variety of colours and sizes. Roses are beautiful flowers, and while they might take a little work, they make a great addition to any garden – small or large.

 

These are just a few examples of hardy plants that you can choose for your garden. When choosing plants for your garden, it is important to consider the climate in your area as well as other environmental factors. With a little planning, you can create a beautiful and low-maintenance garden filled with hardy plants.

 

What are your must-have hardy plants? Let me know in the comments below.