If you live in cooler parts of the country, then winter can be rough on a hedge. Since there is not much else to see in the garden, hedges become much more prominent at that time too, so their appearance becomes more important. With the risk of storms increasing, and a mood of uncertainty in the weather, no matter where you are, taking steps to protect your hedges from damage makes a lot of sense.
Prepare Your Hedge for Winter
- Choose the right hedging plants – Thuja Green Giant for zones 5 to 8, Emerald Green Arborvitae in colder regions
- Water well through the fall – even if rain has fallen, soaking the roots protects against winter burn
- Apply fall fertilizers – use something designed for fall, with high potash for cold-resistance
- Trim your hedge in fall – a trimming in September will create a tight structure and reduce the risk of damage from snow, ice or strong winds
Correct Choice of suitable Hedging Plants
If you are still in the design-phase of your hedge, then some careful consideration of what plants to use makes sense. Across most of the country Thuja Green Giant is the most popular pick, by a long way. Not only is it fast-growing, it is tough and reliable, and stays a fresh green color all year round. Great as this plant is for hedges, it is hardy just to zone 5, and if you are on the northern limits of that zone, and certainly if you are anywhere in zone 4, then it may not be the right choice for you. Winter lows below minus 20 degrees are the cut-off point. If you are likely to have nights below that, then Emerald Green Arborvitae is the best choice. This plant is hardy all the way down to minus 40, so there are few places in the country where it won’t come through the winter untouched. It is a bit slower growing, and it can sometimes bronze a little in winter, but if you live in cold areas, it is the right choice – an outstanding hedging plant for cold places.
On the other hand, once you are well into zone 5, and certainly all the way up to zone 9, Thuja Green Giant has to be the top, number-one choice for everyone who needs speed, lush green growth, and reliability across a wide range of soil conditions.
Keep up the Water Supply
Although we associate fall with rain, sometimes it doesn’t come, or at least not in great quantities. Because of their overhang, hedges keep light rain away from their own roots, and it is easy for your hedge to be dry when colder weather arrives. Dryness at the roots is without doubt the single greatest cause of winter damage in evergreens. Once the ground freezes, the roots can no longer bring up water to the green parts. Exposed to the cold, dry winds of winter, and also to the warming and drying effects of winter sun, that foliage will dry out, without the moisture being replaced. When spring comes, suddenly you are looking at dried-out foliage on your hedge.
If you do one thing for your hedge before winter, make it a good soaking at the roots, or even a couple, separated by two or three weeks. Even if you have had some rain, it never hurts to get lots of water onto the roots, especially of a newly-planted hedge. Not only does the water in the soil slow-down freezing, it ensures that the leaves are fully hydrated when winter comes. Some of the water may not freeze, so the roots will still be able to supply the foliage with enough to prevent winter burn and death. Keep soaking right up to freeze-up, whenever that comes for you. You won’t regret the little bit of work involved. If you run a soaker hose along the line of your hedge, it will make the job very easy, and it will be useful in summer too, when periods of drought arrive.
Use a Fall Fertilizer
You might think fertilizing your hedge in fall is a bad idea, but it isn’t. You need to use a suitable fertilizer – check your local garden center or hardware store for something labelled for fall use on hedges. These have lower levels of nitrogen, so they don’t stimulate new growth. They also have elevated levels of potash (Potassium), which helps cells pump the maximum amount of water into the foliage, stimulating thicker cell walls. This in turn brings greater resistance to cold, diseases and insect attack too. Sometimes the nitrogen is ‘packaged’ in a form that sits dormant over winter, and then becomes available as the soil warms, which is a fantastic way to get spring fertilizer to your plants as soon as they begin to grow. These products have many benefits, and should be used more by home gardeners. Always follow the manufacturer’s directions for application, and use early in the fall, generally before early October.
Trim Your Hedge for Winter
When it comes to protecting your hedge against damage from snow and ice, or strong winds, nothing works as well as trimming in early fall. The hedge that is a little overgrown, with areas where snow or ice can lodge, or with branches that can be whipped around by strong winds, is the hedge that suffers winter damage. The more you trim, the tighter your hedge will grow, and it is that dense, tight growth that sheds snow, and filters the wind, keeping your hedge from injury. Thuja Green Giant is fast-growing, so to build a strong structure it needs regular trimming. Always trim in all directions across the face of the hedge. If you only trim upwards – a common mistake by beginners – you will encourage long branches on the face of the hedge. These are easily dislodged by wind, and then broken, leaving large gaps that can take several years to fill in. Cut downwards as well as upwards, to create horizontal, tufted branches that stay tight in the hedge, preserving a solid, unbroken face.
When trimming the top, if you get significant winter snowfall, then a rounded shape, on a narrow top, will shed snow, and ice much better than the classic square top. Square works well if you are zones 8 or 9, where snow is a rare or non-existent event, but regular snow calls for the protection of a rounded top.
Just make sure you do this important job early on in the season. The end of September is the deadline in most areas – but mid-October is fine in warmer zones. Any later and you may create soft new growth that is more prone to winter damage.
These few simple steps will greatly increase the likelihood that come spring, you will have a perfect hedge, ready to go for another season. Hedges are great backdrops for any garden, and they deserve a little attention to help them along.