Reading the spring flush: even, one sided, late or barely there

The first flush of the season is the clearest report you will get on a tree all year. Everything the roots did through the cold months, and everything wrong in the ground where you cannot see it, shows up in how the buds move. A tree that is working pushes evenly. A tree that is not pushes in a pattern, and the pattern is readable.

Four cover most of what you see: even, one sided, late, and short and weak. Treating one as another wastes a season.

An even flush across the whole canopy

Buds break at about the same time from the lowest branches to the leader, shoots extend, leaves harden off and hold their colour. That is a root system in contact with the soil right around the ball and drawing evenly. Nothing to do.

On a tree in its first season after transplanting, an even flush can still be a small one. Shoot extension may be well short of what the same tree made in the ground at the farm, and the leaves may be smaller. That is normal and not a fault. The tree is spending on roots first, and the canopy it can afford is the canopy it builds. Do not feed it hard to force top growth. What you want in the first year is root.

One side moves and the other stands still

An asymmetric flush is nearly always a root or an exposure problem. Work through the causes in order.

• Water. A single dripper, or a hose left in one position, wets one sector of the ball and leaves the rest dry. Lift the mulch and check the quiet side by hand.
• Ground. Compaction from machinery, a paving edge, imported fill, a services trench cut close to the ball. Roots there have nowhere useful to go.
• Drainage. Water standing in one half of the hole, usually the low side or against a footing, drowns roots as effectively as drought kills them.
• Aspect. Reflected heat off a light coloured wall, or a prevailing wind drying one face, slows growth on that side with nothing wrong below ground.
• Orientation. We mark the north face of every root ball before the tree leaves the ground, so it can be planted facing the sun exactly as it grew. Bark that spent its life shaded and is then turned north runs hot, and a tree that has been turned shows it in an uneven flush and, in a bad case, in damage on the newly exposed side.

The fix follows the cause. Water is quick. Compaction and drainage take real work and are better done before the heat than after. Orientation cannot be undone once the tree is in, but shade over the exposed trunk for a season or two carries it through.

The whole tree is late

Nothing is moving while the same species down the street is away. Before deciding it is dead, scratch a twig near the tip with a thumbnail. Green under the bark means live tissue. Work inward until you find green, and you know how much canopy you still have.

A live but late tree usually has one of a few things going on. The root zone may simply be colder than the neighbour's: a south facing bank, heavy wet soil, a frost hollow. Cold soil holds a tree back long after the air has warmed. Or it is planted too deep, with the root flare buried, which slows everything and in time kills. Scrape back the mulch and soil at the trunk until you find the flare, where the trunk widens into the first roots. If it sits below the finished level, that is your answer. Our guide on planting depth and root flare sets out how to check.

The other common cause is a ball that has never been properly wet since it went in. Site soil and ball soil are different textures and water follows the easier path, so you can have moist backfill around a dry ball. Probe into the ball itself, not the ring around it.

A short pale flush that stops

This is the pattern that concerns me most, because for a fortnight it looks like recovery. The tree breaks bud, opens small pale leaves, barely extends, then stalls. Some of those leaves scorch at the margins and drop.

It usually means the tree spent stored reserves to open a canopy the root system could not then supply. The cause is almost always at the ball: too deep, too dry, standing in water, or a hole dug in clay with a bucket so the sides are glazed and roots cannot get out. Check depth first, then moisture in the ball, then drainage. If the sides are glazed, break them open at several points around the perimeter.

Two things not to do. Do not prune to balance the tree, because removing leaf removes the engine that builds the roots you are waiting on. And do not reach for high nitrogen fertiliser: a tree that cannot supply the canopy it has does not need telling to make more. We grow ours on Auxinone, a Vitamin B1 root stimulant, and seaweed extract, which is the support a struggling tree can use, aimed at roots rather than top growth.

What is worth doing while you wait

Keep the water going on the ball to the pattern it was set: 150 to 200 litres, weekly for the first month, then fortnightly for about six weeks, then only in prolonged dry spells. Keep the mulch at 75 mm and clear of the trunk. Check ties and stakes so nothing cuts in as the trunk moves. Then leave the tree alone. A good deal of damage gets done by anxious intervention, and a tree working through a slow start recovers on its own timetable.

If you have read the pattern and still cannot place it, tell us what you are seeing. The planting library carries the rest of the establishment detail.