Yew

Light and exposure

Yew grows just as well in full sun as in the deepest shade, which makes it one of the very few conifers able to keep a dark corner of the garden green. Against a north-facing wall, under the canopy of large trees or in an enclosed courtyard that gets only a few hours of light, it stays dense and green where most conifers turn yellow and thin out.

As a hedge or a specimen, it takes full sun on a south-facing front just as readily as the shade cast by a neighbouring house. That is a real asset for closing off a town garden visually or hiding a fence in a shady corner where hardly anything else really holds.

Watering

Once established, yew copes remarkably well with drought thanks to deep roots that reach far below the surface for water. A specimen planted more than two or three years ago can more or less do without watering, even during the dry summers we now see more and more often.

In the first year or two after planting, though, water regularly in dry weather, especially in sandy soil that drains fast. The real danger for yew is never a lack of water but an excess of it: soil that stays waterlogged for weeks eventually rots the roots.

Soil and repotting

Yew is not fussy about soil type: it grows just as well in chalky ground as in heavy clay, in poor stony soil as in ordinary garden loam. That is one of the reasons for its success as a hedging plant right across Belgium, where soils vary enormously from one plot to the next.

The one truly non-negotiable requirement is good drainage. In compact clay that holds water over winter, it is worth loosening the ground deeply and adding gravel or coarse compost at planting time, otherwise the roots eventually suffocate.

Temperature and humidity

Yew is perfectly hardy in our climate and needs no winter protection at any age. It shrugs off the harshest winters the Herve region can throw at it, late frosts as much as sudden mild spells.

The trade-off for this toughness is slow growth, ten to twenty centimetres a year for an established plant. There is no need to worry about it or force things with extra feeding: it is precisely this slowness that gives yew its density and its longevity, a yew planted today can still be standing in two centuries.

Pruning and upkeep

Pruning is done at the end of summer, ideally between mid-August and the end of September, once the year’s growth is finished but with enough season left for cuts to heal before winter. This is the time to clip hedges and topiary to a clean line, since yew takes a hard cut very well.

Its great advantage over other conifers is that it regrows from old wood: a hedge that has become thin, overgrown or neglected for years can be cut back hard, almost to the trunk, and it will come back. To keep a hedge full at the base, taper the sides slightly narrower at the top than at the bottom, so light still reaches the lower branches.

Pests and diseases

Yew is one of the healthiest, hardest to kill conifers in the garden, with very few serious diseases to report. The one real risk is root decline from Phytophthora, a rot that sets in in waterlogged soil and eventually browns and kills whole branches, sometimes the entire plant.

You sometimes see scale insects, small brown crusts stuck to the shoots, or the yew gall midge, a tiny insect whose larva causes an artichoke-shaped deformity at the tip of young shoots. In both cases the damage stays limited, and cutting off the affected shoots is enough to keep it in check.

Propagation

Cuttings are the most reliable way to reproduce a specimen true to type, but it takes patience: take semi-ripe shoots at the end of summer or in autumn, set them in a sandy mix in the shade, and wait, rooting often takes several months.

Sowing also works but stays slow and uncertain: the seed inside the red aril has a deep dormancy that often delays germination by two winters. In the wild it is birds, fond of the sweet aril, that spread the seeds after digesting them; for the gardener in a hurry, taking cuttings or simply buying a plant remains the more sensible route.

Toxicity

Yew is one of the most toxic plants found in our gardens, and this should never be taken lightly. Every part of the tree, needles, bark, wood and above all the seeds inside the berries, contains alkaloids called taxines, extremely dangerous to people and to livestock alike. Only the aril, that fleshy, sweet red covering around the seed, is edible and safe; the seed itself, if chewed or bitten into, releases the poison. Never plant a yew near a pasture or an enclosure for horses, cows or sheep: a few handfuls of needles are enough to kill a large animal, and accidents are sadly not rare. With children, keep them away from fallen berries on the ground and watch closely if they go picking.

Month-by-month care calendar

Green Hub tips

• Never plant a yew near a pasture or an enclosure: a few needles are enough to kill a horse or a cow, taxine does not forgive.
• Prune at the end of summer, between mid-August and September: the cuts heal before winter and the shape stays crisp all through the cold season.
• A ruined or thin hedge is never a lost cause: yew is the only conifer that regrows from old wood, a hard cut back always saves it.
• Allow three to four plants per metre of hedge for a dense line from the start, and be patient: yew grows slowly but lasts for centuries.