Written by s • Should I Trim My Trees?

Trees are great to have on your property, bringing beauty and shade, cleaning the air and removing CO2 from the atmosphere – we should all be planting more of them. Older trees, though, can need some care, especially when they grow near your home, or could potentially become a hazard if branches started falling. Sometimes too, a tree has been planted a little too close, and it may need reducing in size. There are lots of reasons why trees might need trimming, and usually the best way to have a large tree trimmed is by hiring an arborist, or tree surgeon. Winter and early spring is often the best time to have trees trimmed. It is much easier to see what needs to be done, since the branches are bare, there is less clean-up, with no leaves to worry about, and the snow and frozen ground protects your lawns and beds from damage.

Does My Tree Need Trimming?

This can be a tricky question but standing back and looking at your tree can give you a lot of information to work with.

Are there dead branches or limbs?

Look up into the crown of your tree – are there branches without any leaves? Over time small and medium-sized branches die. It doesn’t necessarily mean your tree is diseased – some branch death is completely natural. However, these dead branches can become entry points for disease, especially if they break in a storm and leave a jagged break, or worse, tear away some live bark. Removing them cleanly will reduce that risk, and this general clean-up can stimulate some new branch growth too, improving the look of the crown and rejuvenating the tree.

Smaller dead branches are only a nuisance when they fall, but larger ones are a hazard, causing injuries if they fall on someone. Sounds unlikely, yes? In fact, you are much more likely to be killed by falling tree limbs than by terrorists – it’s hard to get accurate numbers, but perhaps 700 people are killed each year in the U.S. by falling objects, mostly trees. Plus, if limbs overhang your home, a falling branch can cause extensive damage to your roof, and maybe end up in your bedroom.

How Far Back from Your Home is the Tree?

We always emphasize setting trees far enough back from your home when planting, so they don’t end up overhanging the roof. Most people greatly underestimate the final size of that cute young tree you are excited about planting, or only look at its potential size after 10 years – a blink of time to a tree that might live 200 years of more.  Trees planted alone spread much more than when they are planted among other trees, so always overestimate the final size, and plant at least half the mature spread of the tree from a building. In other words, if a tree has a potential spread of 50 feet, it should be at least 25 feet from a building or property line, and 30 feet would be better.

This isn’t always done, and we often ‘inherit’ a mature tree that is too close when buying a property. If you have a large tree with limbs projecting more than a few feet over the roof, and especially if they have yellow leaves, few leaves, or no leaves at all, then they should be removed. On the other hand, in more open areas, with mature trees, dead limbs provide valuable nesting and observation sites for larger birds, like hawks and eagles, so in some areas it makes sense to leave them alone.

When a tree falls in the forest, it isn’t a hazard – when it falls on a home, it is. This doesn’t mean you should cut down a tree growing too close – although there are certainly times when that is necessary – but some skilled trimming can bring safety and security, while keeping your tree, and the beauty it brings.

Are There Limbs Crossed or Rubbing?

If the center of your tree looks crowded, with limbs crossing over each other, or rubbing together, this is a potential problem. Some trees do naturally have a lot of branches ascending from a point where the trunk ends, but most should spread out in a more open fashion, so that as the limbs grow and expand freely, without interfering with each other. This is something that is ideally done when a tree is growing, rather than leaving it until the limbs are large. If you planted a tree a few years ago, perhaps 5 or 10 years back, then some trimming now will be relatively easy, the cuts small, and they will heal and cover quickly. Now is the time to open up the center of the tree, leaving the best limbs radiating up and out, with plenty of room between them.

How Are the Crotches?

Before jumping up and punching me, you need to know that arborists call the space between two branches a ‘crotch’ – see, no offence meant.

The space between two limbs of roughly equal size will be at different angles – sometime close together, sometimes wide apart. We might think that tight is good, but no, these ‘narrow crotches’ lead to problems. As the limbs thicken, bark becomes trapped in the closing gap, and this weakens the joint, since wood is stronger than bark. These ‘narrow crotches’ often end with one limb tearing away, removing lots of bark beneath it, and potentially meaning the tree will die. When assessing your trees, These are danger points, and one of the two limbs should be removed as early as possible.

Double Leaders

Many evergreens grow with a strong, central trunk, surrounded by radiating branches. The ‘narrow crotch’ problem develops here too, but in a unique way, when two branches start to compete, and two stems grow at the top of the tree, creating a ‘double leader’, or what is basically a very, very narrow crotch. This develops exactly the same bark problems, and besides not looking so good, it can cause catastrophic damage when (rather than if) that crotch splits.

Keep an eye on your upright evergreens and cut back the tip of one of the leaders by a couple of feet at least, to maintain a single leader for as long as possible. Keep one shoot ‘head and shoulders’ above the surrounding branches and everything will be fine.

Remember the Future

Finally, if you have mature trees on your property, what about the future? Trees can live a long time, but they are not eternal. The mature tree you enjoy was almost certainly planted by someone who never saw it as you do – yet they planted it anyway, thinking of the future. We live in an age of ‘instant gratification’ but planting a tree for future generations is something that can bring gratification too – by feeding our dreams of a better future, and our hopes for those who come after us. Even if you have mature trees, there is almost always a spot to plant new ones somewhere. These will develop, and be available when one day, sadly, that grand tree you love is gone, even though we could well be gone too.