Hazelnut Water Shoots: What Are They and What Should You Do?

Water shoots are the strongly growing, vertical, largely unbranched shoots that emerge from the older wood or main framework branches of a hazelnut, particularly after hard pruning or in response to vigorous root growth. They are conspicuous and fast-growing — easily reaching two metres or more in a single season — but they contribute little to the fruiting potential of the plant in the short term and can shade out productive lateral wood if left unchecked.

Why Do Water Shoots Appear?

Water shoots are triggered by the dormant buds that exist on older wood throughout the hazelnut framework. Hard pruning, physical damage, or simply the natural vigour of a well-established root system activates these buds into rapid growth. They are more common in the years following a heavy pruning or coppicing, as the plant uses its stored root energy to regenerate. A hazelnut growing on rich, heavily nitrogenous soil also tends to produce more water shoots than one on moderate fertility ground.

Are Water Shoots a Problem?

In small numbers, water shoots on a hazelnut are not a serious problem. They become problematic when they are numerous enough to shade the productive lateral branches beneath them, or when they occupy space in the centre of the canopy that should be open to light and air. Left for several years they become thick, vigorous stems that are increasingly difficult to remove cleanly. On a poorly managed plant, water shoots can eventually dominate the canopy at the expense of the older, more productive fruiting wood.

When and How to Remove Water Shoots

The easiest time to remove hazelnut water shoots is in midsummer when they are still pliable and relatively soft at the base. Rub them off with your thumb at their point of origin if they are small enough, or cut them cleanly at the base with sharp secateurs. Midsummer removal reduces the energy diverted away from the fruiting wood at the critical time when nuts are filling. A second check in autumn during the main pruning session catches any that were missed in summer. Cut cleanly with no stub, as stubs left on older wood are prone to coral spot and other wood-rots.

Using Water Shoots as Replacement Stems

Occasionally a water shoot is produced in a position where a new framework stem is needed — for example, to replace an old stem that has been removed or has died. In this case, allow one well-positioned water shoot to develop as the replacement, removing all others. Tie the selected shoot loosely to a cane in its first year to keep it upright and direct. It will mature into productive fruiting wood within two to three seasons. This selective use of water shoots is a useful management tool for renewing older hazelnuts without resorting to full coppicing.

Reducing Future Water Shoot Production

The best way to reduce excessive water shoot production is to avoid very hard pruning all at once, which triggers the most vigorous dormant bud activation. A gradual approach — removing one fifth to one quarter of the oldest stems each year rather than all of them at once — renews the plant progressively without the same burst of water shoot growth. Moderating nitrogen inputs also helps, as lush feeding encourages the vegetative vigour that produces water shoots at the expense of flowering and fruiting.