Planting a screen along the boundary, or planting a hedge on your property, is often one of the very first things people do when they take over a new home. Maybe you have an ugly view, or need screening from neighboring houses. Perhaps you want to block out a noisy highway, or perhaps you just want a neutral, green backdrop for the garden you are creating. Whatever the reason, some early planning should come before buying, so let’s look at the key questions to ask. The answers you give will help you choose the right plant, and ensure your screen or hedge grows into a great success.
Will it Grow in My Area?
This is an obvious first question, but one that is not always asked. It is important to choose a hedging plant that is reliably hardy in your area. Something that could be damaged or killed by an unusually cold winter is not a good choice, since over the decades of the life of a hedge, that unusual event becomes a certainty, sooner or later.
Basically. there are three sturdy, reliable hedging plants that are widely recommended for different growing zones. In the coldest areas, for zones 2 to 5, the best choice is Emerald Green Arborvitae. This is an extremely hardy plant, so although it is not as fast-growing as some other evergreens, you can be sure it will not be damaged by cold, no matter where you live. For zone 5 and up, the number-one choice is Thuja Green Giant. This is the fastest growing evergreen available, and it will grow in a wide range of environments.
You will notice that in zone 5 you have a choice, and you should think about how exposed to north winds your hedge is going to be. If the site is very open and exposed, then Emerald Green Arborvitae is probably the best pick. For more normal areas you will find Thuja Green Giant will grow very well, and give excellent results.
inally, if you live in a very hot, dry area, especially in zone 8 or higher, the Italian Cypress is the best bet for you. This is a very drought-resistant evergreen, with strong upright growth and deep-green foliage. It clips into an impressive hedge, and no matter how hot it gets, it will always look perfect.
What is My Soil Like?
When it comes to soil, most evergreens are adaptable, and they will grow well in most types of soil, from sand to clay, and from acid to alkaline. More important is the drainage. If your soil is often wet, with water standing around for days, and is damp even in the hottest parts of summer, then in zones 5, 6 and 7 Emerald Green Arborvitae is your friend. For average conditions in zones 5 and up, Thuja Green Giant is by far the best choice, because it will grow well in all but the wettest places. If your soil is often dry, and you live in zone 7 or more, then, as you might expect, the Italian Cypress has got to be your first choice. However, if you are able to supply irrigation to your hedge or screen, then you can enjoy the more rapid growth and brighter color of Thuja Green Giant, all the way to zone 9.
The second consideration for soil is its pH – the acid/alkaline balance. Luckily here there is no problem with most evergreens. One of the parents of Thuja Green Giant is the Western Red Cedar, and this tree grows naturally on very acidic soils. Its other parent, Japanese Arborvitae, thrives in alkaline conditions. Their Green Giant child is happy in either, so unless your soil is very unusual, and has a pH below 4.5, you don’t need to give it a second thought. Even if you have very acidic soil, adding garden lime when you plant will fix the problem. Consult your local garden center for advice on the quantities you need – they usually know local conditions well. If you are choosing Italian Cypress, it is naturally happy in acidic soils, but it will tolerate alkaline soils well.
How Much Sun Will My Hedge Get?
Most hedges are planted in open areas, so they receive lots of sun. The major evergreens we have been discussing all thrive in full sun – so no problems there. If you are planting in a shadier area, consider the kind of shade you have. If it is from a tall building, so that you can see the open sky overhead, then you should have no problem growing Emerald Green Arborvitae or Thuja Green Giant. Sadly, Italian Cypress really needs at least 6 hours of sunlight a day, and will not grow well in any kind of continuous shade.
If you are planting underneath trees, consider if they are deciduous trees or evergreens. If they are deciduous, things should be fine, as long as the shade is not too dense and continuous all day. For those situations, or in the dark, all-year shade of evergreens, consider something more shade tolerant, such as Yew or perhaps one of the Holly Bushes. These clip into beautiful hedges, although the rate of growth will be slower.
Important considerations when planting in shadier places are water and nutrients. Shade trees take a lot of water in summer, and they also deplete the nutrient reserves in the soil. Providing some kind of irrigation, and having a regular, full-on fertilizer program for your hedge, are both things that will make a huge difference. As well, follow a ‘little but often’ trimming program, since trees in shade are naturally thinner in growth, and regular trimming will develop denser growth. Don’t wait a long time between trimming, because then you will leave your plants thin, and in shade it will take longer for them to thicken up again.
How Many Trees Do I Need?
For screens, which receive little or no trimming, we usually use a wider spacing. For smaller plants like Emerald Green Arborvitae, or Yew Trees, a 4-foot spacing is ideal. For larger plants, like Thuja Green Giant, six or eight feet apart will give you impressive results. Italian Cypress is naturally narrow and upright, and although it grows tall, 4 feet apart is ideal.
If you are planning a hedge, then reduce these distances to 2-feet apart for those smaller trees, and to 3 or 4 feet spacing for Thuja Green Giant. If you want a thick, very-dense hedge, and have the width for it, double rows, at the screening spacing above, and with 3 or 4 feet between the rows, will give you a super-solid hedge, that will block noise very effectively.
To figure out how many plants you need, just measure the length and divide by the spacing. Always add a couple of extra plants for a shorter hedge, and five or more extra for a long hedge. This is insurance against an error in your measurements. If, after planting, you have trees left over, plant them in another area, at the same spacing as your hedge. These will be useful back-ups if you lose a tree or two in the first 5 years – you can just dig them up and slot them right into the space created by that loss. They will have dense root-balls, and it is hard to get smaller plants to ‘take’ among the roots of mature hedges. After that you probably won’t need them, so transplant them around your garden as attractive accent plants.
If you have considered these steps, your hedge, no matter what you plant, will be an enormous success, and give you a beautiful result.