Prepare Your Thuja Hedge for Spring

Although we may still be well inside the ‘winter zone’, spring is not far away, so it is not too early to start planning for the coming season. Thuja Green Giant is a tough, fast-growing and self-reliant plant, but a few simple steps in the early part of the season will give it an extra boost that will see it go from strength to strength as the background of your garden.

Feeding Thuja Green Giant

While this is a plant that thrives even in poor soil, attention to its diet is never a mistake. Rapid-growing plants need plenty of nutrients to achieve peak performance, and your Thuja is no exception. Evergreens need a good supply of nitrogen to make those green leaves, so choose a fertilizer formulated with a large first number in the fertilizer formula. That set of three numbers tells you almost all you need to know, and for hedges it should be something like 15-10-10, or 12-5-8. The exact numbers will vary, but make sure that first one, which stands for nitrogen, is bigger than all the rest. Most fertilizers formulated for hedges will be like that, and which you choose is mostly about personal choice and convenience of application. Water-soluble forms are ideal when your hedge is newly planted, or in its early years. These forms carry the nutrients right down to the roots, where they are quickly absorbed and used for rapid growth. They must however be dilute, because too much will burn the roots, so they do not last long, and need reapplying every few weeks.

As your hedge matures, regular feeding can become a chore, so now it is time to switch to a granular fertilizer, which only needs applying a couple of times a year. A little more expensive, but worth the cost, are slow-release forms, where the fertilizer is encapsulated inside a pellet. This allows a slow, steady flow of nutrients, and one application in early spring is all you need.

Trimming Thuja Green Giant

Late winter is an ideal time to inspect your hedge for any winter damage. If branches have been pushed out at awkward angles, resist the temptation to push them back in, and trim them back instead. Long branches pointing out are telling you that your trimming technique need a little work. When trimming, run the trimmer in all directions across the face of your hedge, so that you don’t encourage a ‘comb-over’ effect. Branches should grow out more or less horizontally, with dense tufted ends, not trail upwards in long stems. These are more prone to breakage and becoming dislodged, and if they break they can leave ugly black holes that take a season or more to fill in.

Trim off any dead tips or smaller dead branches, and do a light trim all over. The most important thing when trimming is to make the face of your hedge lean inwards slightly. The light must reach the lowest branches, so that they continue to grow well, or the base of your hedge will become thin and open over time. Since the upper growth is always more vigorous, this means you will be removing more foliage from higher up. Cutting off the same amount all over will encourage the top to swell outwards, which is not only unsightly, but bad for the hedge too.

If you have had some breakage from snow building up on the top, then start trimming it in a rounded shape. This will shed snow more effectively than the crisp ‘flat-top’, and prevent snow and ice falling inside and pushing branches out of line, or even breaking them.

Salt Damage

Thuja Green Giant is moderately salt tolerant, especially if the salt is air-born, but direct splashing of salt from roads and driveways can cause damage. If you have a lot of brown areas on your hedge, and these may not be visible until the warmer weather arrives, then some screening may be needed. Next fall, run some stakes 2 or 3 feet away from your hedge and pick up a roll of burlap from your local garden center. Attach this to the stakes, so it is well away from the hedge, but between it and the source of salt. The burlap will catch the salty water and protect your hedge. If you put it too close, the wet, salty burlap will touch the hedge and do more damage than good.


As summer arrives, water stress is possible, especially on a young hedge, and especially if you can’t easily water it. An organic mulch spread over the root zone in spring will not only provide valuable nutrients, but it will also conserve moisture. The water levels are usually at their highest in early spring, so mulching then will prevent that from evaporating, as well as trapping spring rains. That way the soil will be much damper when the dry weather arrives, and any stress form dryness will be reduced. When young you should water your Thuja Green Giant plants regularly, but an established hedge will survive normal dry conditions without any problems at all.


These few simple things will give you a flying start to spring, and by taking care of them as early as possible, you will leave yourself free for other gardening pleasures, while your hedge does its duty as a beautiful background and screen.