One of the most common questions I am asked is ‘ We want to screen this – that or the other – what do you recommend as the best trees for screening?’
We then go through the litany of what height is the subject they are trying to hide and how far away is it and are they bothered if the screening tree is evergreen or deciduous, and how much room do they have to play with in terms of planting and growing their chosen plant.
In view of the fact that this subject is very prescriptive I have listed below a selection of ideal screening plants, their habits, likes, dislikes and needs; hopefully from this list you will be able to spot the best one for your particular needs.
Alnus Glutinosa / Incana
The common alder. This tree is often used as a very effective wind break as well as a good screen. It is very wind tolerant and loves wet soil conditions; it also needs plenty of room. It will happily grow to 15 meters in height so if you have the room it can be very effective. Another attribute of this tree is that , although it is not strictly speaking evergreen , it does hold onto it’s foliage for a long time in the Autumn and is one of the first trees to break out in leaf in the Spring, in addition , it is usually well laden with catkins which gives it even more canopy cover. I would suggest that you plant them as ’Feathered Trees’ that is to say young trees about 2 metres tall with all their side branches still in tact ; you can actually grow this tree as a hedge by keeping the tree trimmed at a predetermined height . Plant 2-3 metres apart for effective screening.
Betula Pendula. Common Silver Birch, or Lady of The Woods. If you only need a light screen, and you can tolerate a certain amount of height then this most beautiful tree could be just the answer. It is a light foliaged deciduous tree with beautiful striated silver bark and glorious golden Autumn foliage . It will grow well in wet ground conditions. The light tracery of branches in the winter will afford a surprising amount of screening. As with Alders , plant ’Feathered Trees’. Plant 3 metres apart .
Populus x candicans Aurora . Poplars have been employed as screening trees for generations – with sometimes disastrous results ! That is why I can only recommend one variety of poplar that I am confident will not result in future nightmares. This particular variety of poplar is very well behaved and has some most attractive features. Poplars have been used in the past because of their speed of growth and also the fact that they are quite inexpensive. Populus x candicans Aurora is both of these things, but it only grows to a medium height of about six metres, it’s roots do not seek out every drain in the neighbourhood, and it is both attractive to look at has the most exquisite perfume of balsam which emanates from it’s foliage and is present all Summer. Plant at 2 metres apart for a solid screen and gently prune in the Summer to help keep them in good shape.
For evergreen screening you will have to resort to Coniferous Trees; but be aware that in coastal areas and high elevation situations, Coniferous trees will suffer from wind scorching.
Chamaecyparis Lawsoniana The good old fashioned ’Lawson Cypress’ was the screening conifer pre 1950 , but from that time onwards the dreaded Leyland Cypress took over that role due entirely to the fact that it grew six times faster! However, if you can find any young Lawson Cypress plants then I would still recommend this tree for screening. It is quite variable in growth as it is produced from seed but it will make a very dense, interesting screen – but it is slow growing. Plant 70 centimetres apart.
Chamaecyparis Lawsoniana Hybrids . There are a couple derivative varieties of Lawson Cypress that are well worth using as Screening Trees C.L.Columnaris Glauca is a tidy growing attractive conifer with blue foliage and a neat conical habit and reasonably quick growing. C.L. Golden Wonder is a bright yellow foliaged conifer which grows in a neat orderly fashion. C.L. Green Hedger is another useful Lawson Cypress that is ideally suited to formal screening. These Lawson derivatives need to be planted at 90 centimetres apart, or even wider if you can bear to wait for them to join-up. None of the Lawson Hybrids like wet conditions.
Cupressocyparis Leylandii. The dreaded Leyland Cypress and it’s golden sister C. Castlewellan . It is a wild beast , but a brilliant screening tree . Leyland Cypress and it’s derivatives will easily grow up to 120 centimetres a year in height with a proportionate balance of growth sideways ; it is totally evergreen, not expensive and easy to source in many sizes.
The secret with Leyland Cypress is Management and Application . If you live in a typical urban situation with close neighbours and a smallish garden then don’t plant a Leylandii screen – Plant a Leylandii hedge by all means – keep the plants trimmed regularly every year to what ever height you think is reachable from ground level -say 2 meters – and you will achieve a very neat, dense hedge , forget to keep it trimmed and you will see a green monster rise above you and block out the Sun !
Only use Leyland Cypress for screening where you have at least 25 metres of space between you and the trees and also make sure your neighbour has the same space between him and the Trees ! Plant them at least one and a half metres apart or they will grow with a very weakened trunk , and be prone to being blown out in very strong gales as they grow taller. Leyland Cypress is a Parkland tree – not a Garden Plant !
Cupressus Arizonica Fastigiata. A very rugged conifer with deep blue foliage and a pleasantly pungent aroma. It is capable of withstanding strong winds without too much scorching. It has quite a neat habit and is very distinctive as a screening tree. Plant at one and a half metre spacing; it must have well drained soil conditions.
Thuja Plicata Atrovirens . The lovely ‘Western Red Cedar’ This gem of a conifer has most of the attributes you might be looking for as an evergreen screening tree; but be aware that it will get quite large eventually; so make sure you give it a reasonable amount of room – say 10 metres from any building. The shape of the tree is conical but not too skinny. It is very dense in its foliage, and a beautiful deep green in colour. One of the best things about this conifer is the fantastic aroma of balsam that the foliage gives off if it is even lightly brushed against . I used to have one specimen where I had to mow and I always looked forward to brushing against it as I went past ! Plant at 2 metres apart for the best results ; this is not a quick growing tree , but well worth waiting for….!