Jingzhe: the first real inspection of the year

Jingzhe is the point where the growing season becomes visible. Buds have swollen enough to show colour, the first insects are moving, and any damage the winter did becomes obvious. An hour spent inspecting now saves a season of catching up later.

The five-minute inspection that covers most of it

Lift each pot and compare its weight with the others of similar size. A pot that is unusually heavy suggests water is not draining; an unusually light one suggests the root ball has dried out or separated from the pot wall. Look at the buds: they should be swelling evenly, and any branch where buds are still tight while its neighbours have swollen has a problem below it. Check the trunk base for soft patches, and look under the pot for roots emerging through the drainage holes, which means the pot is already full.

Repotting begins, in order of species

This is the start of the repotting window for most deciduous species, and the order matters. Repot the earliest-flushing species first: elms, then maples, then hornbeam and zelkova, then the late species such as oak and beech, which are best left until the buds are almost opening. Pines are repotted as the buds begin to move; junipers and other conifers can wait until April. Repotting everything in one weekend because that is when you have time is how trees get repotted at the wrong moment.

The first pests of the year

Aphids appear on the first soft growth, usually within a week of bud break on maples and elms. They are easiest to handle when the colony is still on the outside of the shoot tip: a firm jet of water knocks them off, and a weekly check keeps them from establishing. Once the shoot tips curl, the insects are inside the curl and much harder to reach. Slugs are the other early problem, particularly on trees standing on the ground, and a ring of copper tape around the bench is more reliable than bait where pets or children are around.

Feeding, and the mistake of starting too early

The instinct to feed hard as growth starts is understandable and wrong. Roots are only beginning to function, and fertiliser applied before they can take it up accumulates as salts in the soil, which can burn the new root tips that the tree has just produced. The correct sequence is: no feed until the first leaves have opened and started to darken from their initial pale colour, then a quarter strength feed, and full strength only once the first flush has hardened. On a deciduous tree in a temperate climate that is usually about four weeks after bud break.