There is a particular kind of heartbreak in the garden that comes from pruning a forsythia in February. You stand back, admire your tidy work, and then watch as spring arrives with barely a golden bell to be seen. The reason is simple: early flowering shrubs such as forsythia and ribes bloom on growth they made the previous year. Those flower buds are already sitting on the stems, waiting patiently through the cold. Cut those stems in winter or early spring, and you have thrown away the entire display before it ever had a chance.
The golden rule, then, is to wait until the flowers have faded. Once the last blooms drop, the shrub shifts its energy into making new shoots. That is your window. Prune immediately after flowering, and you give the plant the whole growing season to produce strong, healthy growth that will carry next year’s blossom. Leave it too late, and you risk cutting off the young wood that is already preparing to flower. For most early flowering shrubs in the UK, that means late April through to early June, depending on your local climate and the variety in question.
Forsythia is the classic early riser, often brightening hedges and borders from March onwards. It is also remarkably forgiving, which is why so many gardens end up with a tangled thicket of old, flowerless stems. The secret is not to treat it like a hedge. Shearing the top with hedge trimmers creates a dense, twiggy outer shell and a bare, unproductive centre. Instead, use a renewal approach.
Start by removing any dead, damaged or diseased stems. Then look for the oldest, thickest branches. These are usually darker and have a rough, peeling texture. Using secateurs or loppers, cut them right back to the base or to a strong low framework. Aim to remove about one in three of the oldest stems each year. After that, cut back the stems that have just flowered to a healthy side shoot or outward-facing bud, reducing them by about a third. This encourages bushy new growth from the centre rather than just at the tips. You will end up with a shrub that is a mix of ages, with plenty of young wood ready to bloom next spring.
Ribes sanguineum, or flowering currant, is another early bloomer, with its pendulous clusters of pink or red flowers appearing around the same time as forsythia. It has a distinctive, slightly spicy scent that many gardeners love, and it makes a fine informal hedge or border shrub. Like forsythia, it flowers on old wood, so the same principle applies: wait until the flowers fade, then act.
Begin by cutting out any weak, spindly growth and any stems that are crossing or rubbing. Then remove the oldest, darkest stems at ground level, again taking no more than a third of the total. Shorten the remaining flowered shoots by about a quarter to a third, cutting just above a strong bud. If your ribes has become overgrown and woody, you can renovate it over two or three years rather than all at once. This avoids shocking the plant and still leaves you with some flowers in the meantime. After pruning, a generous mulch of well-rotted compost or manure will help it recover and push out fresh growth.
Renewal pruning is the technique that keeps early flowering shrubs young, productive and full of bloom. It mimics the natural aging process of a woodland shrub, where old stems eventually die and are replaced by new ones from the base. Here is how to do it properly:
This method encourages strong new growth from the base, which will ripen over summer and carry the following year’s flower buds. It also improves air circulation, reducing the risk of fungal problems.
Forsythia and ribes are not alone. Several other popular UK garden shrubs flower on old wood and benefit from the same after-flowering treatment. These include deutzia, weigela, philadelphus (mock orange), kerria, and amelanchier. Each has its own habit, but the principle is identical: prune immediately after flowering, remove old wood, and encourage new growth. For deutzia and weigela, cut back flowered shoots to a strong side shoot and thin out old stems at the base. Philadelphus can be treated a little more lightly, simply removing the oldest branches every few years. Kerria is best pruned by cutting out some of the older green stems after flowering to keep it from becoming congested.
If you miss the window and the shrub has already started into new growth, do not be tempted to prune anyway. Leave it for another year. The flowers will be sparse, but you will avoid causing more damage. Instead, mark your calendar for next spring so you are ready the moment the blooms fade.
Even with the best intentions, a few mistakes can undo your hard work. The most common is pruning too late in the season. If you cut in July or August, you remove the young wood that would have flowered next spring. Another is over-pruning, which removes all the old wood at once, leaving the shrub weak and flowerless for several years. Shearing with hedge trimmers is a third trap, as it creates a dense outer layer that shades out the centre and reduces flowering.
After pruning, give your shrub a little TLC. Water it well if the weather is dry, and apply a balanced fertiliser or a mulch of garden compost. Avoid high-nitrogen feeds, which encourage leafy growth at the expense of flowers. A light dressing of blood, fish and bone in early spring can help, but only if the soil is not already rich. Finally, be patient. A well-pruned forsythia or ribes will reward you with a spectacular display the following year, and for many years to come.
The Seasonal Plot shares practical, down-to-earth guidance on british seasonal gardening and outdoor living for readers across the UK.
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