15 Dec Is it time to say goodbye to your tree?
It’s a worry anyone with a tree in their garden often has for a month or two but doesn’t tackle immediately in the hope it will resolve itself – a tree may be dying.
Like so many issues in our lives, the loss of a long-enjoyed tree can be upsetting as we often become sentimentally attached to them by watching them change colour through the seasons and growing year by year as well as usually performing a useful function in the garden.
One or more things can be responsible for the decline of a tree. They include its age, unsuitable growing conditions, a pest or disease problem or environmental stresses such as poor establishment, too much soil around the base, soil compaction, waterlogging, drought, poor uptake of nutrients or specific nutrient issues.
So, if you have your suspicions one of your trees is past its best, here’s what to look for:
• Stunted growth
• Coming into leaf late or sparsely
• Premature leaf fall
• Yellow or browning leaves
• Dieback and shedding of branches
How to tell if your tree is dead
Because deciduous trees look dead in Winter without their foliage, you need to properly check the health of a tree using the following three-step method:
1. Do The Scratch Test on shoots: scratch the bark on the shoots with your thumbnail or a small knife. A stem with green under the bark is alive. If it’s brown underneath, it’s dead. Living shoots will also have smooth, firm bark, while dead or dying shoots have flaking, peeling or wizened bark.
2. Do The Scratch Test on branches: if the shoots are dead at the tips, do the test on branches to check if they’re also dead. If most or all of the upper parts of a tree are brown under the bark, the plant is very likely to be dead.
3. Do The Final Test: to be sure, you can also to scrape the bark of the main stem just below the soil line or on the roots. If this appears dark in colour, especially with any sign of soft, rotting roots, then you can be confident your tree is dead.
Trees which still show some signs of life (e.g. green under the bark or firm roots) can be left for a few months or until Spring to see if they improve. If they continue to get worse, or fail to return to growth in Spring, you can reasonably conclude it’s dead.
How to prevent your tree dying
If the cause of your tree’s ill health isn’t clear, the RHS recommends a professional assessment. Large trees often need further on-site tests to determine if the tree is at risk and if any potential treatments are worth considering.
There are a range of interventions based on trying to improve the growing conditions which can be taken to try to prevent your tree dying, based on the diagnosis of what’s causing its problem:
• Check there is appropriate light and cut back or remove any obstacles that may be blocking the light or creating a shadow during the day.
• Assess the surrounding area and make sure there are no other hungry plants or shrubs nearby taking up all the nutrients. It this is the case, replanting them to another spot could be an easy solution.
• Removing excess soil from around the stem or trunk base. With a spade or trowel, carefully remove excess soil from around the base to expose the root flare. Take care to avoid damaging larger roots as this can stimulate or aggravate suckering. Unless the roots are very close to the surface, also reduce the level of the soil in the main root area under the canopy. Cover the area with mulch such as composted bark or wood chippings, but avoid the root collar. For high-value trees, a professional can use air tools to minimise damage to the roots. Bio soil stimulants can also be added to the soil (see below).
• Removing vegetation from around the base to a minimum of 1.2m (4ft) diameter. Fertiliser and organic mulch is also best applied.
• Limit movement over the root area to ease soil compaction, especially when the soil is wet. Also remove all vegetation, including lawn turf, from the main rooting area under the canopy – to remove the need to enter the area – as well as reducing competition from other plants. Keep the area covered with an organic mulch – so the microbiological activity will improve the soil. You can also look at applying general fertiliser to the rooting area in Spring to boost growth. Compressed air tools can also help reduce compaction.
• Install drainage if waterlogging is a major issue. If it’s feasible, look at moving smaller trees to a better position.
• Water the tree regularly if drought is identified as a factor. You should also apply mulch when the soil is moist in order to reduce evaporation. In Spring, apply a general fertiliser to boost the tree’s growth, but avoid overfeeding is it encourages growth which is more prone to drought damage.
• Commission soil analysis and follow its recommendations to identify and address a specific nutrient deficiency. Once you have the results, applying a general fertiliser, ideally early in the growing season, to help growth. If possible, remove vegetation from under the canopy before feeding. Organic mulches are a worthwhile investment in the long term as they slowly improve the soil’s texture, reducing the leaching of nutrients and evaporation from the soil – resulting in better nutrient availability.
If the problems are particularly bad you can look at more advanced methods:
• Mechanical relief of soil compaction: compressed air tools can relieve compaction in the main root area and be used for removing extra soil from around the base. Professionals usually have these and the experience to use them to best effect.
• Add soil stimulants: Bio-stimulants can improve biological activity in the root area to activate the tree’s natural defences against diseases. Products include biochar, mycorrhizal fungi, rock dust, wormcasts and trichoderma. This can be used alongside air tools.
• Pure wood mulches: UK studies have investigated the disease suppressant properties of some pure woody mulches which leach a variety of chemicals and compounds into the soil when shredded and applied as a mulch. Where soil and mulch interact is an area of high biological and enzyme activity as well as diversity of fungal organisms and is where diseases can be suppressed.
What to do when your tree is past its best
If, sadly, despite your best efforts, your tree is beyond recovery, it needs to be removed to minimise the risk of infection to neighbouring trees and plants, as well as making space for replanting and mitigating the risk of it falling and damaging something or someone.
Depending on the size and proximity to your home or garden structures, you may be able to safely dig the tree out or fell it yourself. If it’s bigger or too close to structures at risk of damage, it’s best to call in a professional. They can also deal with the stump for you. Or you can follow our advice on how to deal with it yourself.
Get in touch
Get in touch to arrange a free visit and quotation for professional advice on looking after your trees and what we can do using the latest techniques and our professional-grade equipment. As fully qualified arborists, we’re happy to offer advice on tree care.