When it comes to hedges, there are certain things we want from the plants we use. When choosing which plant to buy, it is best to go through a check-list of what you need, and what the different choices offer. Let’s look at the most important features and see how some common hedging plants stand up to some scrutiny. If you use check off these features against the different plants you are considering, you can eliminate the guess-work and be able to make the right choice for what is often an investment that will last for 30 years or more.
Should be evergreen
It is true that the nearest thing to an ‘instant hedge’ will be a deciduous plant, perhaps one of the fast-growing willows. These can grow 6 feet or more in a season, which is much faster than any evergreen. But the downside is pretty much a deal-breaker. For several months of the year you can see straight through your hedge, destroying any ideas of privacy. Now sometimes this doesn’t matter. For example, in a larger garden it is common to use internal dividing hedges, and in winter these can be bare without it becoming an issue. In fact, letting the low winter sun through can be a big plus factor. Trees like beech make beautiful deciduous hedges, and beech has the advantage of often holding its brown leaves for most of the winter anyway.
But when privacy is an issue – and for most gardeners it is the main reason for planting hedges – the evergreen plants are really the only way to go.
Should stay green all year round
A problem with some evergreens is discoloration during winter. The foliage of some plants turns brown – usually called ‘bronzy’ – or scorches with the combination of sun and low temperatures. Since in winter your hedges are often the most prominent thing in your garden, how much nicer is it if they are rich green through the coldest months? It might take some research to confirm that the plant you are looking at does this – nobody advertises defects – but two good choices that are always green are Thuja Green Giant and Emerald Green Arborvitae.
Should grow fast
Every plant takes time to grow to where we want it, but some of course take longer than others. Only you know how quickly you want a mature hedge, or how long you are prepared to wait. Some trees that produce very long-lived and beautiful hedges take a long time to get there – yew trees for example. Others do it very fast – Thuja Green Giant will add at least 3 feet a year from the second year of planting until about the fifth, after which it will slow down to a foot or two. But that is ten feet in 3 years, and often enough to give you what you need. That tree has been proven in research to be the fastest-growing evergreen, but climate plays a part too, and in colder areas you cannot expect suitable plants to grow as well. Emerald Green Arborvitae is great in cold zones – it is hardy to at least zone 3 – but it will only grow a foot or so in a year.
Should be hardy
Make sure the plant you choose is well-matched for your growing zone. If you don’t already know it, it is easy to enter your postcode and find out. Often it is possible to ‘push’ your hardiness zone with many plants, and grow one zone colder than it says, but don’t try this for hedges, because they are too important to risk them being wiped out in a harsh winter. So always select plants that are thoroughly hardy in your zone. This applies at both ends – something often overlooked when you live in warmer places.
For example, if you live in a moderate zone – usually considered to be zones 5 to 7 – then Thuja Green Giant is the perfect choice. In colder zones use Emerald Green Arborvitae, as it is hardy throughout zone 3. It also makes a good choice for a smaller hedge in warmer zones up to 7. In warmer areas Thuja Green Giant will do well in zones 8 and 9 if your local climate is not too dry. If you have long, hot, very dry summers (often called a ‘Mediterranean climate’) then a plant that thrives around the Mediterranean is the best choice – Italian Cypress, either in its natural deep green or in one of the bluer forms, is very drought resistant indeed, and grows very well in hot and dry locations, as well as making great specimens in areas as cool as zone 7.
Should tolerate both sun and shade
It is a bit unusual to be putting in a long hedge that is always in full sun for its entire length. Except for yew trees, which tolerate shade well, but grow slowly, most evergreens do best in sun. But if your hedge will pass through both sun and shade you want to choose a plant with reasonable shade tolerance. Most Arborvitae need plenty of sun, or they grow very slowly into thin, open plants. But Thuja Green Giant will grow almost as well in 50% shade as it does in full sun, making it a great choice for this difficult but common situation.
Should be drought resistant
We accept that for the first few years we are going to give our new hedges some care, in the form of regular watering in summer. Once they become established, though, we would like to be able to leave them to take care of themselves. If we only have to trim once or twice a year, that would be ideal, as most people have limited time for their gardens. Summers can vary a lot, and even in places which normally have regular summer rain, drought year happen. So look for good drought resistance in established plants, unless you have unlimited water available, and a full irrigation system. Thuja Green Giant is more drought resistant than most evergreens, although Italian Cypress certainly beats it, surviving months of dryness without damage.
Ready to choose?
Now you have a better idea of what to look for, making that final choice of plant variety for your new hedge is a lot easier, and you are much more likely to have a top-rate outcome, and soon see the hedge of your dreams, right in your own garden.