As so many exciting green shoots start to burst through in the garden, there’s a real sense of ‘out with the old and in with the new’. The remnants of old growth on perennials suddenly look ‘so last year’ as new growth slowly pushes through. After a good pruning stint at the start of spring, the garden can look very bare and empty but you can rest in the knowledge that it’s set up for another year.
Then once spring is in full swing it’s already time to start pruning off some of that young growth that just a couple of months earlier was the cause of so much hope and expectation. Funny thing, gardening!
More pruning advice:
Why prune now
Getting rid of last year’s growth is important to give the garden a healthy start in spring and for shaping plants so that they grow how and where you want them to. At the start of spring, new shoots on perennials can be damaged if you leave all of last year’s growth intact when the plant is putting on strong new shoots.
Plants that produce flowers on growth made this year also benefit from a prompt prune at the beginning of spring so that they don’t get too tall and leggy, and ensure they flower at a height where the flowers can easily be enjoyed.
Plants that have finished flowering by spring and flower on the previous year’s growth also need a spring prune, in order to give them enough time to put on new growth that has matured enough to flower by next year. If you wait until summer, it might effectively say ‘too late’ and decide not to flower at all next year.
What to prune now
Deciduous grasses
As the days gradually draw longer and that wonderful feeling of the start of spring begins, it suddenly seems strange to have last year’s grasses still intact in the garden. Those ghostly remnants no longer seem have a purpose and are probably strewn close to ground level and looking rather messy. Cut all this growth back as close to ground level as possible, with a pair of sharp shears, taking care to avoid any new growth. The same principle applies for the old flower stems of perennials that have been kept intact for their winter structure, such as echinacea, rudbeckia, Verbena bonariensis, which can be cut down to ground level.
Growing Greener
Leave loose and twiggy pruning material in a sheltered corner of the garden as a ‘free-for-all’ for birds looking for things to use to build their nests. Strands of deciduous grasses and thin, thornless twigs from shrubs can come in handy for blackbirds, robins and song thrushes.
Winter-flowering shrubs
The following plants are the equivalent of someone who’s been out for a run, cooked themselves a lunch from scratch and made it to work on time. In other words, they achieved much, while a lot of their neighbours were still sleeping. I’m in the still sleeping camp, but I digress! By spring, these plants have already finished flowering and need cutting back.
Witch hazel
The good news about pruning these scented beauties is that you don’t have to do much. Once flowers have finished, just prune any damaged stems back to healthy growth and completely cut off any dead or very spindly stems. You may also want to cut off a stem if it is crossing into the path of another or spoiling the shape of the plant.
Forsythia
If left unpruned, forsythias tend to look rather strange, becoming gangly thickets with all the flowers sitting on the top like a fruit cake where all the fruit has sunk to the bottom but in reverse. Early spring is the time to tackle it, so you still get flowers next winter.
Cut out around a quarter of the thickest, oldest stems back to the base to stimulate new shoots from the ground to replace them. Cut back the stems that have just flowered, snipping to a new shoot lower down, at the desired height. Thin out the growth in the centre of the plant, so that you can comfortably see through it. If it looks like an impenetrable barrier, thin out some more stems!
Mahonia
These evergreen shrubs don’t need a lot of pruning but early spring is the time to chop if the plant is becoming leggy and bare. Cut back gangly stems to just above some healthy foliage, being quite drastic if you want the plant to be much shorter. If the whole plant looks like it needs to start again, you can prune each stem back to 15cm (6in) from the base. Give the plant a good mulch and water well if soil is dry afterwards, to help it recover from the haircut!
Winter heathers
It’s so easy to forget about winter-flowering heathers, once the colour is gone and there are so many other exciting spring things to focus on in the garden. Keep them in your mind long enough to remember to get out some sharp shears and lightly trim the whole plant, cutting off the old flowers and some of the stem that was holding them. It’s best not to cut into thick woody growth because it won’t re-sprout readily. Cut the sides a bit lower than the top to get the classic dome-shaped effect. You’ll be glad you took the trouble to trim when all that currently grabs our attention has past and we are grateful for any colour, once winter returns again.
Summer flowering shrubs – hard pruning
Some shrubs need to be given the ‘cruel to be kind’ treatment in spring, in order to give their best show. Don’t be scared of hard pruning, get stuck in!
Buddleja
If buddlejas are left unpruned they will still flower but become old, gnarled, creaking heavyweights whose branches start to split as the weight of them gets too much for the plant to bear. Just look out of the window next time you take a train journey and you’ll see what I mean. Cut all the stems back to about 10cm from the base and you’ll have a slender, young shrub that can mingle with tall perennials rather than tower over them like a tree. You may need a pruning saw to cut back thick stems. Make a cut underneath the stem you want to prune, before you saw through the top, to stop it splitting.
Hardy fuchsias
Few plants ‘play dead’ as well as hardy fuchsias. At the end of each winter they look positively funereal. As spring begins, look out for the tiniest of new shoots appearing on the stems too. If in doubt, scrape back part of the stem with your fingernail and if its green, then you’re in business. Make sure you are using sharp secateurs or loppers and cut each stem back to around 8cm from ground level. If your garden is in a very cold part of the country, leave pruning until later in spring when the weather has warmed up a bit more to reduce the risk of frost damage to new shoots.
Spiraea japonica
Pruning in spring helps give a good display of these summer flowers that are loved by butterflies. The flowers are held on new growth and some, such as ‘Goldflame’, have colourful foliage too, and pruning will give a brighter display of leaves because they will be held on vigorous young stems. Cut each stem back to 30cm from ground level as the plant begins to show signs of life in early spring.
Lavender
Although ideally pruned after flowering in summer, you can give lavenders a trim in spring to tidy them up if you didn’t get around to it last year. Snip off any old flower stems that were missed last autumn and snip back any broken stems, and shoots that were soft and damaged by frost. Use very sharp shears or secateurs to trim back last year’s growth, snipping off up to 2.5cm (19in) of the stem. Take more off the bottom than the top to give a rounded shape.
The Chelsea chop
It might seem strange to cut back perennial plants in spring when they have laid dormant for so long in winter but it can greatly improve their look and result in more flowers. Snipping back the new growth on herbaceous plants will encourage more sideshoots, resulting in a greater number of smaller flowers.
This pruning gets its name from often being done at the end of spring, during Chelsea Flower Show week (nothing to do with football managers being sacked!) but it can be done much earlier to make your plants bushier and more compact, and you can do it more than once too, if required. Flowering will be a bit later than if you hadn’t chopped but this is a handy trick for lengthening the flowering period, if you just cut half of the plant back, this chopped half will start and, crucially, finish flowering later than the unchopped half. This cutting back is especially useful if your garden is exposed and young growth on perennials are prone to flopping over. Stake them well too though! Try it for achillea, phlox, asters, echinacea, penstemon, monarda, verbena, helenium.
Thrifty tip
If you need a new pair of secateurs or pruning saw and can afford it, investing in a good quality pair is likely to work out as better value for money than buying the cheapest ones.
A good quality pair of sharp secateurs will also be beneficial for the health of your plants, potentially leading to fewer casualties. If the blades don’t cut cleanly and stems are squashed, it can be an entry point for disease, resulting in plants lacking vigour and potentially needing replacing.
Disinfecting secateur blades in between pruning different plants will also help reduce the risk of disease spreading from one plant to another.