World leaders will gather in Scotland’s largest city to agree a strategy to help save life on the planet as we know it.

Action speaks louder than words, so the current crop of politicians meeting in Glasgow must act now not merely set targets for their hapless successors many years down the line.

Reducing CO2 emissions tops their agenda when tackling this global crisis. Individuals as well as governments have a role to play.

As is well known, forests play a vital part in absorbing and retaining carbon from the atmosphere. In photosynthesis, plant leaves soak up CO2 and release oxygen. The carbon is then used for growth, and this makes trees, our largest plants, extremely important.

The Scottish Government recognises this since it’s estimated that current plantations and woodland absorb 95m tonnes of CO2 annually. So a major national tree planting programme is now under way – 10,660 hectares of land were planted up last year and this will rise to 18,000ha. by 2024/25.

As I stressed in my climate change series last year, we gardeners must individually do our bit as well. Mony a mikle maks a muckle.

If every gardener in Scotland planted a tree, we’d jointly make a muckle contribution.

There’s a tree for each and every garden, from a patio to an estate. The dwarf mountain pine, Pinus mugo, grows very slowly in a pot and provides year round foliage in return for some water.

Nurseries and garden centres offer many different bonsais and small trees like Japanese maple, Acer palmatum, for containers. If a tree has to pay its way, you could always go for a dwarf apple or pear.

Trees for pots and containers are there for the long haul, not to be felled, but think twice before cutting down a larger tree as its stored carbon will be released into the atmosphere.

This happens in a sitka spruce plantation as well as the garden. Sitka spruce is felled after 30-40 years and during timber extraction, the soil is badly churned up making the site look like a war zone. This disturbance also releases large amounts of stored carbon. It was shown in a recent RSPB report that 53% of stored carbon from a tree plantation was released within 15 years and a further 23% was burned.

So these plantations arguably do more for timber and paper production than carbon sequestration. But such benefits do not apply if you fell or severely prune a tree in the garden.

Only cut down a tree as a last resort because this largely undoes your good work. There’s obviously no alternative if you inherit an unsuitably large specimen after moving to a new house, but do choose carefully when planting a new one. Check a tree or shrub’s final height and spread and how quickly it grows. A good nursery or reliable organisation like the RHS can advise.

If, like me for example, you want one of the 450 or so species of Berberis, choose the size you want. Although most Berberis grow slowly to around 1.5-2m, B. calliantha only reaches 75cm and B. x frikartii ‘Amstelveen’ has a final height of a metre. But one of my favourites, Berberis vulgaris, reaches a larger 4m.

Frequent pruning also releases carbon. So your tree or shrub should need minimal trimming. Even a dwarf Kilmarnock willow needs extensive pruning and sucker removal.

Cornus varieties grown for their spectacularly coloured stems must also be pruned extensively. Only fresh stems are coloured so they need to be cut back every year. This also applies to the delightful Salix varieties with yellow, red and purple stems.

Plant of the week

Betula medwedewii ‘Gold Bark’ is a compact, spreading birch tree slowly growing to 10m. The bark has attractive shades of gold and bronze and the leaves turn a stunning gold in autumn.



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