It has been a pleasant start to spring, with a little rain and warmer days. Your deciduous trees will be coming in to leaf (if they haven’t already) and you should have enjoyed some blossoms from such plants as prunus, crabapples and flowering quince. Hopefully, by now you will have completed, or be close to finishing, repotting any conifers that need it.
As the new season growth commences on trees that have been dormant over winter, the work really begins. Pruning is so important in spring. If you have any cherries, apricots or quinces, prune the foliage which develops very quickly after flowering finishes. This will increase branch development, as well as helping to keep your tree looking tidier.
Carefully watch the development of maples in general and Japanese maples in particular. As the second pair of leaves develops either pinch them off when they are quite small or use tweezers. If this practice is not done, long internodal growth (the spaces between leaves on a developing branch) will occur. An added advantage in doing this is that it also induces back budding.
Most species of elm can be pruned back to two or four pairs of leaves to increase ramification. It is a good idea to then allow six pairs of leaves to develop and cut back again to two or four leaves. Take more care though when pruning Zelkova, as they resent being pruned back too hard, and a trimmed stem may die back past the point you planned.
Spring pruning is not over yet, as evergreens are growing rapidly, especially privets, and conifers will need lots of attention. Remember that if there are any parts of a tree which are not developing well, do not prune them until that section has become stronger.
Check any wiring on your trees carefully, as branch thickening during spring may lead to wires cutting in more quickly, leaving unsightly scars behind. It is generally better not to wire during spring for that reason, particularly with deciduous species. Remove wiring from a tree if the branch has set, or replace wire in the opposite direction if it has not.
With so much active growth happening, it is time to start fertilising all your trees (except for recently repotted ones). Whether you liquid fertilise fortnightly at half strength or monthly at full strength, or every three months with a granular food, it doesn’t matter, but fertilise you must, if you want optimum growth and health for your trees. What is essential is that you follow the directions from the manufacturers and do not over fertilise.
As always, make sure your trees do not dry out. We have had several quite windy days lately, and it is in this type of situation that the growing medium is prone to quickly drying out. Trees in very active growth, particularly if they have been recently repotted, can suffer damage to their foliage or even die if moisture is not readily available. If one of your trees does dry out completely, it’s a good idea to immerse the entire pot in a tub of water until the bubbles stop rising (several minutes), to make sure that the entire root mass doesn’t become ‘water repellent’ and that future watering will get to where it’s needed.