You have decided you need a hedge or screen on your property, maybe to give you privacy, to hide an ugly view, to reduce noise and air pollution, or to block cold winds and trap some warmth in your garden. Now comes the choosing part. It’s like deciding on a sofa – lots of choices, and many of them have good features. So how to decide? Let’s look at the major questions you need to ask, when choosing the plants to grow that screen, and see how they stack up against each other.
Evergreen or deciduous?
This is the first question you need to ask yourself. An evergreen hedge might seem the obvious choice – after all, you usually want screening in winter too, but there can be advantages in a deciduous screen. Sometimes the area you want to screen is not used in winter, and a leafless hedge lets through a lot of light, so when the days are short in winter that might be just what you want – perhaps to let more light into your home. Remember that the sun is lower in winter, so a hedge can cast a long shadow over a lot of your garden. But yes, mostly the choice is going to be evergreen, for the privacy it gives, and the beautiful neutral green backdrop it creates in a garden.
Tall or shorter?
Just how tall you want your hedge or screen to be is an important consideration. If you plant something with a maximum height way more than you need, it will need constant trimming, and could in the future become a real menace to you and your neighbors. Thuja Green Giant is a terrific choice for a large hedge or screen but remember it will reach 30 feet tall or more in a relatively short time – as tall as the top of the roof of a two-story house. That is perfect is you need that height, and it will also get there fast, growing 3 feet or even more a year during its early years.
But if you want a hedge around 6 to 8 feet tall, you would be better choosing something else – perhaps Emerald Green Arborvitae, which will only reach 12 or 14 feet even if it is never trimmed. Sure, it will grow more slowly, but since you don’t want it so tall, your hedge will be ready in the same number of years. . .
Where do you live?
Climate has an enormous impact on which plants will grow well for you. Always stay well within your climate zone when choosing something as basic as a screening plant. It is fine to experiment with a shrub or even a small tree that might not be fully hardy for you, but don’t do that with a hedge. Across a very large part of the country Thuja Green Giant grows well – from zone 5 to zone 8 or 9. In colder areas the best bet by far is Emerald Green Arborvitae, which is perfectly hardy in the coldest areas, all the way through zone 3.
The second part of climate – besides winter minimum temperatures – that should be considered is rainfall. Unless you have extensive irrigation available, and that is no longer a very acceptable choice in many communities, you need to consider drought resistance. Thuja Green Giant is considered ‘drought resistant’, that is, established plants will be unaffected by the sort of summer droughts that are relatively normal in the east. When you move into arid states like Utah or Arizona, much longer periods of drought are normal. There much tougher plants are needed. Winter drought, combined with low temperatures, such as in the Dakotas, or even in Minnesota, call for plants that are both hardy and drought resistant. There plants like the Spartan Juniper, hardy to zone 4 and very drought resistant, become top hedge choices. In states with regular extended summer droughts, like California, and with mild winters, hedge plants like the Italian Cypress and the Arizona Cypress are your friends.
How long can you wait?
If you badly need this screen to make your garden habitable, then plants that grow rapidly in their early years are going to be top choices. Here there is no doubt that Thuja Green Giant has the opposition beaten cold. With proven growth rates of more than 3 feet when growing in a field, that can be topped with generous watering and fertilizer in many garden situations. The only potential rival for that top spot is the Leyland Cypress, but that tree has had disease issues in recent decades. In fact, the rise of Thuja Green Giant is directly related to disappointment with Leyland Cypress in warmer southern states in particular.
If you do need that extra height Leyland Cypress can bring – it will reach as much as 60 feet in a few decades – then choose the Murray Cypress, a more disease-resistant variety that was introduced relatively recently. Do be careful with Leyland Cypress though. If you don’t need, and have room for, all the height and bulk, then avoid it for something more modest. Thuja Green Giant is almost a dwarf evergreen against it.
For those drier areas Italian Cypress is not far behind these two, with rates of about 2 feet a year, but Arborvitae generally only grow about a foot, or even less, in a year, so if you don’t need them for winter hardiness, sticking with Thuja Green Giant makes a lot of sense.
What about deer?
This is always a big question, and it’s one that’s hard to answer, because those pesky critters are unpredictable, and what they will eat depends quite a lot on just how hungry they are. Broadly speaking, Thuja Green Giant is mostly ignored by deer, or only touched a little. Arborvitae, on the other hand, are almost always eaten, as is Leyland Cypress. Junipers and Italian Cypress are usually left alone, as they are rather spiny, but not always. . .
As you can see, there are lots of things to take into account when choosing your evergreens. For a ‘Three Bears’ garden, that is, “not to hot, not too cold, etc.” Thuja Green Giant stands out as the ‘go to’ choice, but if your situation is more extreme, other choices may be more suitable for your particular circumstances.