Not all trees are green! Reduce carbon footprint and support wildlife by planting wisely

Not all trees are green! Reduce carbon footprint and support wildlife by planting wisely

  • Professor Antonelli says old forests soak up more carbon than new ones 
  • Nigel Colborn explores what gardeners can do for trees, climate and wildlife
  • British gardening expert says trees and long-term shrubs support nature   

During the last General Election, one bizarre sideline was the tree-planting pledge ‘contest’.

As polling day neared, each party leader increased the number of trees their government promised to plant if elected.

It was mostly hogwash, based on the premise more trees equals more carbon absorbed. According to Professor Alexandre Antonelli, from the Royal Botanic Gardens at Kew, old forests soak up more carbon than new ones. They’re also richer in biodiversity.

He suggests trees should be planted first where woodland has been degraded or destroyed. They should not be planted in natural grassland or wetlands.

Feeding the birds and the bees: Apple blossom in a beautiful cottage garden

But as gardeners, what can we do for trees, climate and wildlife? Well, more than you think.

gardens big enough for medium or large trees already support nature. Those trees and long-term shrubs will store carbon, and every little helps. 

TINY SPACES 

Small gardens lack space for such trees, but can be rich in nature, especially if there’s room for a shrub or tiny tree. If you have space only for patio pots, using peat-free compost will reduce your carbon footprint.

In a tiny town garden, trees are hardly an option. But if there’s room for a shrub, it will provide wildlife shelter and food. Flowering plants in pots or beds also help nature, if there are flowers for much of the year.

Among the small trees on my terrace, I grow the dwarf cherry Prunus incisa and a snowy mespilus, Amelanchier x grandiflora. The blossom of both feed pollinators, and birds snap up insects from their bark. Both bear fruit, snaffled by blackbirds, and are carbon neutral.

Nature needs its own highways for creatures to travel. If there are street trees near your home, those will work with your garden to provide that network.

So if your garden is stocked with flowering plants and sheltering shrubs, it will enhance biodiversity. The vegetation also cools the city in summer while absorbing carbon dioxide.

If there’s room for a single tree, that makes a difference. A berry-bearing holly would be easy to keep small. It could provide food and shelter for birds, too. With small or medium gardens, modest trees can lock up carbon. They could also be part of a wider planting scheme, with shrubs and flower borders.

The trees need not be natives.

Britain’s woodland contains oaks, limes, beeches or hornbeams among other native species. Some can be pleached or grown as hedges. But for garden trees, you need small to medium ornamental varieties, preferably, with year-round garden value.

FRUITY FAVOURITES 

Blossom bearers such as cherries, hawthorns, apples and rowans are great for wildlife. They make attractive features and can be kept to size by pruning.

When choosing, favour those which bear fruit for birds. You may consider elder a hedgerow weed. But insects take the nectar and birds, squirrels and voles feast on elderberries. Elderflower cordial is easy to make too and delicious, especially with gin. Decorative varieties include Black Lace and the older Guincho Purple.

In my mid-sized garden, the most wildlife-friendly tree is a gold-leaved, grey alder, Alnus incana. It grows in moist silt and has cone-like female fruits accompanied by clusters of red male catkins.

Most of our garden birds love that tree and so do I.