To Guard Or Not To Guard
We've planted trees for hundreds of years before the arrival of the plastic tree guard. John Evelyn didn't need them, so why do we now? Some suspect an element of commercial opportunism at work here!
They are a chuffing nuisance, that's for sure. They can be difficult to fit but - much worse - have left a terrible mess behind them.
Planters started to use guards in the early eighties. There are essentially three different types of guard on the market - spirals for hedge plants, shelters for shrubs, and long tubes for trees. They were principally produced to protect new plants from animals like deer, rabbits and voles, but also prevent wind rock and give the plants a bit of a more favourable microclimate to grow in.
But Are They Really Necessary?
You bet - foresters haven't just been using them over the last 30 odd years for appearance's sake, or because they enjoy littering the countryside. When they were first introduced they reduced failure rates around 25%. So what's going on that's changed, to make them this helpful?
Well, first off, I suspect a lot of trees planted in the "good old days" failed if they weren't pampered. Nowdays, even without the luxury of hot and cold running gardeners, good stock planted properly should see mortality rates under 10%. Further, if you were planting in areas where livestock grazed, in days past you would have used guards - you'd have built your own. Something wooden, or employing the local smith to knock something up if your project was something posh. For small scale orchard planting, for example, homemade wooden guards are still the best way forward. If you've done this yourself you'll realise how time consuming and expensive it is though.
Secondy, there's been a significant - massive - increase in deer populations in the countryside, and grey squirrels in town and country. We've lost several new hedge schemes over the years as deer nibbling has meant they haven't been able to get away. Squirrels can cause terrible damage too, particularly in young woodland.
People are also putting trees in different locations. We're less likely to plant in thorny scrub, which protects saplings, and more likely to plant in urban environments, where trees are likely to be damaged by deliberate or accidental human agency. It's so easy to ring a young tree with a strimmer, or run over it with a lawn mower. You might not even see it.
Guards have also helped if using weedkiller to keep the area around new planting clear of weeds and grass. They protect small whips against accidental spraying (this isn't a practice we wouldn't necessarily recommend, by the way!).
The Problems With Guards
Until now, all three types of guard have been made out of non-degradable plastic. This is particularly bad news for the hedge spirals, which get brittle and shatter into smaller and smaller pieces, which then just sit on/in the soil. Laughably they have been marketed as "photodegradable".
The short story is that there are only now - just - properly biodegradable versions which work. We've trialled all sorts of biodegradable guards over the last decade, and they've been pretty useless. They've been too difficult to use in the field, or they've disintegrated, or they've just not worked. Most were eye wateringly expensive. We did a large scale field trial of biodegradable hedge guards a few years ago on a planting project in Norfolk. We never found out if they did degrade properly as most of them ended up in the North Sea after a week!
We've been selling compostable hedge guards for a year or so, which are a half way house. They're more expensive, but it's a start. Next planting season we're selling completely biodegradable tree guards - hurrah! - and hopefully the hedge guards will follow.
As for the plastic guards, there are now recycling schemes, but the honest truth is most people don't bother taking the guards off and disposing of them.
Why not? It's a surprisingly time consuming job, awkward and fiddly, and, usually, not paid for. I haven't ever seen a tree planting proposal which includes this work.
And if they're not removed in time all these different plastic guards also mess up the natural growth of the plants. At best their branches look squished; at worst terribly contorted, so that they will never make decent looking mature plants. Some forest guards have perforations which are supposed to give, but they often don't seem to work.
You can also get issues with weed growth and moisture inside some tubes and spirals (although not with better designed guards). This can effect tree health.
The Future
It's not very brilliantly prescient of me to predict a big swing back to natural regeneration - which has many advantages - but we'll still need to plant trees too, and of course hedges. Once we've properly switched over to biodegradable guards there's no argument - generally speaking, you should use them.