lal304195When choosing a tree for a garden, take care; a large tree in a small garden will lead to problems in years to come. It will dominate the garden and put it in shade. So, unless you have a large garden, avoid large ornamentals, such as Cedars, the Tulip Tree (Liriodendron tulipifera) or Prunus ‘Kanzan’, and woodland trees, such as Oak, Beech and Horse Chestnut.

Of course you may ‘inherit’ trees planted some time ago, or as here at Old School Garden, ‘allowed to grow’. We had to have some serious tree surgery done to a huge Black Poplar that was getting too big for its boots a couple of years ago. I have an aerial photo of the house and garden taken in 1965 in which you can see the young tree just starting on its life journey. After having its crown and sides trimmed it must still be 45 feet tall and about as broad. I’m also contemplating some more surgery (possibly completely felling) two Oaks that have grown up on our boundary with our neighbours and throw a lot of shade which is causing a lot of moss growth on one roof slope of the house.

Even when you choose a tree that’s suitable in terms of it’s above ground size, don’t forget the impact that the roots might have.

If tree roots are a potential problem, restrict their growth by using thick polythene or a polypropylene membrane, which can be trenched into the soil to act as a physical barrier (or ‘root barrier’) and will prevent the roots growing where they are not wanted. New pipes and drains can also be wrapped in the material to prevent roots seeking moisture from them.

Trees planted in areas that are paved or covered in another solid surface (e.g. tarmac) can cause the surface to lift with time. To combat this, the same types of thick membrane can be used to line the hole at planting time to encourage the roots to grow down, and not along the surface. There are a number of types of root barrier available which can be installed either at planting or to help control roots down the line; here’s one example.

Old School Gardener