Thuja Green Giant is a fantastic, fast-growing evergreen, but when we look at how it is planted in most gardens, there does seem to be a lack of imagination. The nation is covered in straight rows of this tree, standing alone in a neatly-mowed lawn, and I hate to say this, guys, (because it is mainly guys that seem to like this row of soldiers) but there is so much more that can be done. I know that your goal is to mark the boundary of your property, and probably also to block an unsightly view, bring privacy to your garden, or perhaps to reduce wind and snow drift in winter storms. Well the good news is that you can do all those things – and more – with something more imaginative than a blank wall of green.
Clipped hedges I get and have always loved. The geometry itself becomes a garden feature, especially when used as a backdrop to shrub beds. But if you are aiming for low-maintenance, without trimming, then with a little more thought so very much more can be achieved. What I am talking about is planting among and around those Green Giants with other plants and building a more natural-looking privacy screen.
Avoid Straight-line Planting
Sometimes, when space is limited, we need to keep everything in a row to fit it in, but if you have room, consider a different approach. Let’s say you have 100 feet to screen, and very smartly want to use Thuja Green Giant. Typical single-row spacing is between 5 and 10 feet apart, depending on how dense you want it, and how soon you want it to become solid. Now if instead of seeing this as a 100-foot-long straight line, what if instead we see it as also 15 feet wide. Now, instead of a neat row, with everything spaced evenly, we were to take our trees and plant them in groups of 2, 3, or 5 trees, allowing about 6 feet between each plant, diagonally to the row, or in triangles. Space these clusters about 15 feet apart, and now you have a more naturalistic planting, with interesting groups of plants overlapping and creating a much more exciting skyline.
If you have even more width available, you can create overlapping diagonals with rows of these scattered clusters, so that you avoid gaps between them, yet also avoid that straight row effect. But a better approach to that gap is . . .
Add Other Trees to the Row
Now we start to have some fun. If you create those clusters, and perhaps put them further apart – maybe 20 feet – then you give yourself the chance to make your screen even more interesting. Into those gaps you can plant something completely different. Consider the purpose of your screening. Is all-year-round privacy vital, or do you need it mostly in summer? If it’s an issue for summer only, then why not add some deciduous trees? The exact choices will depend on where you live, but these could be trees with fall color, like maple or oak, or flowering trees, like cherry or deciduous magnolia. Smaller trees, like Birch, as top choices for this, and birch is also fast growing, so they won’t get left behind. More upright trees, like the Tulip Tree (or Tulip Poplar) fit well too, and they will never have branches spreading into the evergreens. If the area you are planting is exposed, then tuck those flowering trees closer to the evergreens, on the south side of them, while still putting them partially into the spaces. Crape Myrtles are a great choice too – some become tall, and all are fast-growing and incredibly colorful. Like the Thuja they are drought resistant and do well out in the open.
Alternatively, you can use evergreens. These could be other conifers – perhaps with contrasting foliage color, such as some of the blue spruce, like Baby Blue, or the hardy Colorado White Fir, or beautiful Blue Spanish Fir. Alternatively, holly is a great screening plant, and there are a host to choose from. Pick something upright, with a good berry crop, like the classic ‘Nelly Stevens’, or the fiery ‘Dragon Lady’. If you are in zone 5, choose a hardier hybrid, like ‘Castle Wall’, or ‘Castle Spire’. Once you start thinking in terms of variety, instead of sameness, then many options open up. Remember to match your choices to your growing zone, and choose plants that will grow large fairly quickly, or they will be lost among those big Green Giants. Other evergreen options might include Cherry Laurel, which besides its big green leaves contrasting with the fine Thuja Green Giant foliage, has attractive flowers too. In warmer areas the Wax Myrtle is a lovely upright evergreen, with small glossy leaves, and it’s tough too.
What About Some Shrubs?
So far we have been looking at taller plants, to form the backbone of this mixed screening, but there are also the sides, if you have room. On one or both sides there is an opportunity to add flowering, different plant forms, and fruit for wildlife. In open, treeless areas in particular, screens are valuable refuges for birds and smaller wild-life, providing shelter from storms and sun, nesting sites, and also food. Planting berry shrubs, like Pyracantha or Barberry makes sense. To add greater density, those Cherry Laurels already mentioned are great, and along the sides you can use smaller forms like ‘Otto Luyken’. For early spring flowering, you can’t go wrong with the tough, golden-yellow Forsythia. Why not add some fragrance, with some lilac bushes – perhaps something compact like ‘Miss Kim’, or the remarkable Bloomerang Purple Lilac, which has a second flowering. Don’t plant just one shrub, but instead create drifts, using several, and spacing them apart about 2/3-rds of their mature width. In other words, shrubs that become 6 feet wide would be planted about 4 feet apart.
Let Your Imagination Loose
By now you have will have got the idea of this. Think of clusters of reliable and fast Thuja Green Giant, mixed with taller trees – broad-leaf evergreens, plus flowering or deciduous ones, and colorful conifer evergreens too – that will add variety and interest. Then edge it on one or both sides with drifts of shrubs. Think of interest at different seasons – fall color, berries, spring or summer flowers – you get the idea. Instead of the rigid line of ‘all the same’, you can create a colorful and interesting picture, and still achieve the screening you are looking for.