Thuja Green Giant is the world’s most popular hedging plant – and no wonder. The fastest growing evergreen conifer is also hardy, resistant to heat and cold, and even grows well in coastal areas, where salt-spray can be so damaging to other kinds of hedges. But even the best plant in the world can use a little help to give you its very best, so here are five tips on how to make that happen for you – in your own garden.
5 steps to the Best Thuja Hedge
- Prepare the soil well – dig in plenty of organic material and a starter fertilizer
- Space plants correctly – for a shorter hedge use a 3-foot spacing. For a taller one go with 5 feet.
- Water regularly when young – to get that top growth-rate, water at least once a week
- Have a fertilizer program – modern slow-release fertilizers give the best results
- Trim your hedge to the ideal shape – start when young, slope the sides inwards slightly, and round the top
Prepare the Soil Well
Dig over the area where your hedge is going to be to a width of at least 3 feet. If it’s a long hedge, using a roto-tiller will save a lot of work, but rent a big one that digs down at least 8 inches, and ideally deeper. Go over the area several times, working the tiller deeper each time. You don’t need to take up the grass – just till it right in. Cover the whole area with some rich organic material to a depth of at least 3 inches after you have tilled once, then till it in again. You can use anything – garden compost, rotted leaves, animal manures, or peat moss – but adding that material will stimulate good root growth and quick development in your newly-planted Green Giants. This is especially important if you have sandy or clay soil – both types are improved by adding organic material. Adding some starter-fertilizer rich in phosphates – that second number in the fertilizer formula (e.g.10-30-5) – will also make a big difference. Dig it into the soil along with the organic material you use.
Space Plants Correctly
Resist the temptation to pack your plants tightly together. They will push up tall, but not develop well lower down. You will end up with a hedge that is thin near the ground. Correct spacing will allow the plants to thicken low down, and give you a dense, solid barrier. 3 to 5 feet apart is ideal for a hedge, with the wider spacing for a hedge over 6 feet tall. If you want an untrimmed screen or barrier, then 6 to 8 feet apart will work well. For an extra dense hedge, use a staggered double row, with the rows 2 or 3 feet apart and the plants 8 feet apart.
Water Regularly When Young
The first two growing seasons are vital to get your plants off to a flying start. Until the roots move out from the root-balls into the surrounding soil, they can dry out even during cool and showery weather. If you can, run a trickle-hose between the plants when you put them in. Now you can connect that to a garden hose and water regularly with ease. If you planted during warm weather, then a thorough soak twice a week is not too much. Otherwise a deep soaking once a week is far better than a quick sprinkle every day or two. Once your trees are established, a tough plant like Thuja Green Giant only need watering during extended dry periods.
Have a Fertilizer Program
Even if you have rich soil, fertilizing your hedge will improve its growth. Whatever method you use, choose a good-quality fertilizer blended for evergreen trees and hedges. These contain high levels of the nitrogen needed for rich-green, plentiful and dense growth. Nitrogen comes first in the fertilizer number (20-10-10). Young plants benefit from regular feeding with a water-soluble fertilizer. After the first year, switch to a granular formulation – it’s much less time-consuming to apply. This should be put down as per the directions, in early spring, shortly before the new growth starts. Make sure you spread the recommended amount evenly over the root-zone, which extends a couple of feet or more outside the hedge. Since these fertilizers still need two or three applications a year for top growth-rates, you might want instead to use a slow-release formulation. These are more expensive, but one application lasts the whole season.
Trim Your Hedge to the Ideal Shape
It is very important to start trimming soon after you plant your Thuja Green Giant. Don’t wait until they reach the final height you had in mind. Regular light trimming from the beginning – just an inch or two each time – will encourage dense branching and a strong hedge. You want to have lots of branches growing outwards to make thick sides, and early trimming will develop those.
Beginners at hedge trimming usually try to remove the same amount all over. Since the top grows faster than the bottom, doing this will give you a hedge that is wide at the top and thinner at the bottom. Instead, trim the top more, so that the sides slope inwards a little. This will let light reach right down to the bottom leaves, and keep them growing well. Your hedge will be thick right to the ground, just the way you want it to be. For a formal look, keep the sides perfectly flat, while sloping inwards slightly. In cold areas trim from spring to early fall only – you don’t want to stimulate new growth that could be damaged by a late frost, or turn brown in winter. If you get a lot of snow in winter, then trimming the top rounded – rather than square – will help shed the snow from the top before its weight splits your hedge. Finally, never wait until you must cut back into branches with no leaves on them. These will never re-sprout and your hedge will be ruined.
If you follow these simple guidelines, you will have the fastest-growing, sturdiest and healthiest hedge around. A little bit of care goes a long way with Thuja Green Giant.