Pruning in March with Frances Tophill
As new shoots appear, it’s time to cut out the old growth of ornamental grasses, says Frances Tophill
The spring season really begins to unfurl in March. Daffodils are fully flowering and shoots are breaking through the warming soil. Slugs and snails that have been hibernating are beginning to emerge, so protecting young shoots from them will be paramount – as well as giving everything a good mulch and sowing seeds indoors.
It’s also a period of watching and waiting. At some point this month you can really get underway with spring tasks, but some jobs will have to wait, for example, soil may still be waterlogged, so will become compacted when walked on. Equally, the nights will still be too cold for planting any of your tender plants outside. The birds have now built their nests and, with emerging insects and flowers, there is food aplenty, so the ornamental grasses and herbaceous perennials you’ve been leaving for birds to feed on throughout winter can now be removed. It is also the perfect time to rejuvenate shrubs with a prune, so now is your last chance to get blackcurrants, gooseberry bushes and roses into shape.
Plants to prune now:
March pruning is varied. Evergreen plants become safe to prune as the frost risk lowers and climbers such as late-flowering clematis or honeysuckle can be tidied. Many March prunes are optional, for example, changing a plant’s habit, increasing foliage size or ensuring a compact plant through summer.
Cut back forsythia once the flowers have finished, to strong, new, leafy sideshoots. You can also cut out one or two old stems completely.
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Hebe can be trimmed to achieve neat, compact growth. Cut off any old flower heads from last year at the same time.
- Philadelphus or any other spring-flowering shrub that hasn’t flowered yet, such as ceanothus, escallonia, kerria (see below), lilac, osmanthus or flowering currants. Instead, prune these after flowering in the late spring or summer. Doing so now will remove the flower buds.
- Kerria japonica produces flowers on last year’s growth and shoots from the base. Prune a third of the stems to ground level when it has finished blooming.
- Any shrub, hedge or tree that has nesting birds. It is illegal to knowingly do so – pruning causes huge disruption to breeding and can destroy the eggs of any birds already nesting.
Step-by-step: Trimming deciduous ornamental grasses
Grasses have become a garden mainstay, and each species has its own requirements. The family Poaceae, which encompasses bamboo, meadow grasses, ornamentals and sweetcorn, is vast and varied, with over 12,000 species. Many are annual so need growing from seed each year. Others, like bamboo, carex, Festuca glauca, ophiopogon and pampas grass, are evergreen and should not be pruned unless to control their size. The foliage of deciduous grasses, which has been so useful for overwintering creatures, now needs removing, otherwise, things quickly look messy.
Cut back last year’s growth to no lower than the shoots that are growing up from the base. Wear gloves if you need to as grasses can be serrated. Give each grass a preliminary ruffle to scare off any froglets, insects or small mammals.
Remove any clippings you have taken. These make a really good alternative to wood chips on a pathway, but can also be added to compost heaps. Remember, though, that these tough blades will count as brown matter, not green.
The finished grass will look like a small, neat tuft. Don’t worry if you think this looks a little bare, as grasses quickly put on growth, and soon they’ll be standing tall and you won’t see where you have made your cuts.
Pruning tipAlthough secateurs are indispensable, shears, hedgetrimmers and even strimmers can be used to cut back a large area of deciduous grasses. Of course, you must wear the right protective clothing, and make sure you do not damage the crown and central growth points. The pruning of any plant, no matter what, should always be carried out with clean, sharp tools to avoid pathogen transfer. Maintaining your tools well is key to ensuring that pruning is as safe as possible.
Other plants to prune this way:
Herbaceous perennials with single, strappy leaves resemble deciduous grasses at this time of year. Like grasses, they are monocots and some will look better if pruned the same way, such as varieties of: hemerocallis, iris, sisyrinchium. Other herbaceous perennials left for winter can now be cut back, too. With evergreen grasses, simply pull a gloved hand through the leaves, removing any brown blades.