So you planted a hedge last fall, you have just planted one in the last few weeks, or you are about to do it very soon. Congratulations – hopefully you chose something tough and fast-growing, like Thuja Green Giant, or in colder areas, Emerald Green Arborvitae. In very hot, dry areas you perhaps went with Italian Cypress, but whatever you chose, what happens in the first year after planting will set things up for the rest of your hedge’s life. Let’s see what you can do – nothing complex you can be sure – that will give your valuable new hedge the best start in life.
Prepare the Soil Well
If you have already planted your hedge, then this may be advice too late, but if not, then three things are important:
- Dig Deeply – try to prepare the soil as deeply as possible. Try to go down 12 inches, mixing the soil, and adding suitable materials. For a single tree, prepare an area at least 3 feet across, or a line 3 feet wide for planting a hedge row. If you use a roto tiller, these machines can fool you into thinking you have done a great job, while in fact they just went over the surface. Go over two or three times, working the machine slowly, and letting it sink into the ground as far as it will go.
- Add Organic Material – it doesn’t matter much what kind, just as long as you add it. A layer 2 to 4 inches deep is usually best, and garden compost, rotted farm manure, rotted leaves, even lawn clippings and fresh weeds, are all good materials to incorporate into the soil. These increase the water-holding capacity of light soils, increase the drainage and air content of heavy ones, and add nutrients and valuable microbes too.
- Add Phosphates – this nutrient, needed for root growth, doesn’t move into the soil from the surface for many years, so it must be dug in to be effective. Sprinkling it on top after you plant is completely ineffective. You can use bone meal, superphosphate, or triple superphosphate, it really doesn’t matter, so consider cost. Sprinkle a layer over the soil before you add the organic material. You can’t damage your plants if you use too much, and a solid dusting is about right, so that it is clearly visible.
This is so important, and basic, that it cannot be over-emphasized. New plants only have the soil that was in the pot to depend on, and in warm weather, or when growing vigorously, they soon use that up. It takes some time for roots to move out of this limited space and explore the surrounding soil. So when watering your new hedge, don’t use a spray and water the top only. Use a gently rain head, or a slow-running tap, and soak down close to the stem of each plant, letting the water run deeply down. This will keep your plants happy. You do also need to keep the surrounding soil moist, to tempt the roots to spread out, and this is why many smart gardeners put a ‘leaky pipe’ watering hose – the black, porous kind – down along their hedge. Weave it in and out of the stems, and let it run for a few hours, until the whole area is thoroughly watered. It does a great job, and also saves you the trouble of standing their watering.
Fertilize with Liquid Fertilizers
Feeding hedges is important. Like lawns they get clipped regularly, so foliage is lost, and it has to be replaced. This means more nutrients are used than by an untrimmed plant. Granular fertilizers are the easiest to use, and the most cost-effective, but young plants don’t have big root systems, so they can’t easily access the nutrients from these materials, which need time to migrate down into the soil. Far more effective is a liquid fertilizer, that carries the nutrients right down to the roots with the water. Choose something designed for evergreens, which will have lots of nitrogen to stimulate rapid growth. These fertilizers come as concentrated liquids – the easiest to use – or as a powder – the most economical. The only issue is that because they are dissolved in water, they cannot be very strong, so you need to re-feed every 2 weeks to a month. But for the first year they really make a noticeable difference in the growth rate and foliage density of your new plants, making them sturdy and strong. Stop feeding in early fall, to allow your trees to slow down and toughen up for the coming colder weather.
Start Trimming When Your Start Growing
When creating a hedge, we want a dense, twiggy structure, with lots of tight branching, to give you the solid structure that makes the most private hedge, the best looking one, and the one that resists winter breakage too. The single biggest mistake when people plant new hedges is to let it grow until it reaches the height you want, and then start trimming. This never gives the best structure. Far better is to trim lightly and regularly from day one. As soon as you see new growth, snip off the end inch of it. This will encourage the dense branching you want. It will also allow you to direct the growth upwards, not outwards, so that you have a slip hedge. Don’t forget to keep the upper part narrow, to encourage plenty of growth lower down. Once it gets going, trim very lightly once a month from spring to mid-fall.
Try to keep the front flat, but sloping slightly inwards, and the top horizontal – you might need some strings and a level to get started. Don’t trim at the very end of the season, especially in colder areas, as soft, young growth can suffer winter damage. In the end you won’t reduce the rate of growth significantly, as your new hedge works its way up to your target height, but you will have a great hedge as a reward for that bit of extra work.