Alys Fowler

Getting the best out of your flowering plants

Summer is here and she’s being kind so far and everything is growing fast. A well-timed chop back now can persuade Spring flowering species to have another go.

Plants like lungwort, pulmonaria, siberian bugloss, brunnera macrophylla, lady’s mantle, alchemilla mollis, bergenias and heucheras can all be treated this way. With all but bergenia and heuchera you can cut back heavily, safe in the knowledge that they will flourish with healthy new foliage and if the weather is kind and they are watered well, they often re-flower.

The key is to not let the plants set seed before you cut back the foliage and flowers. Denying the plant the ability to do this means it will try its hardest to bloom again.

Bergenias and heucheras don’t like being cut back to the ground, instead remove any spent foliage and tired leaves, water well, mulch and you’ll find you get a whole new burst of life.

The same treatment works very well for perennial wallflowers such as bowles’ mauve, again, give a hard, but kind haircut so that you remove spent flowers and cut back a little into the foliage so that it remains bushy.

You may end up chopping off a few flowers that are unopened in the process, but it’s better to cut back the whole thing now, rather than wait till all the flowers are finished. This way you’ll get a nice compact plant and I promise, more flowers, otherwise the whole plant can become a little unsightly.

It’s also worth giving any of your perennial herbs a chop now. Mint, rosemary, thyme, sage and Winter and Summer savoury will all try and start to flower from now into the rest of Summer. 

In many ways, this is a good thing because the bees and other pollinators love their flowers, however once the plant flowers the leaves grow smaller and tougher making them less good to cook with. A gentle hair cut now, just trimming off an inch or so will force the plant to bush out with new foliage and maintain the overall shape. They will still flower, but later in the Summer and you’ll get extra tender leaves to harvest and store.

On the whole, cutting back into the woody parts is not great because they often don’t respond with new growth or take a long time to do so. Instead you are aiming to just take a light trim off the soft green growth. Of course, if you regularly pick your herbs you are doing this naturally, but with stuff like sage and rosemary you often don’t pick enough at any one point to do this.

You can also chop back late flowering perennials now by a third to maintain their shape. Plants like sedums, rudbeckias, heleniums, asters, eupatorium and phlox can all have a bit of hair cut now. This will mean that they flower slightly later however because you are forcing them to become bushier plants you’ll not have to do nearly so much staking.

The ice plant, sedum spectabile is very liable to fall about showing its unsightly centre. You can use shears if you want, particularly if you have a large space to work with. After a week or so, you often can’t choose between carefully snipping through with secateurs or going at it with the shears. A useful trick is to cut the front half of the plant and leave the back half unpruned, a layering if you like, which effectively makes the plant stake itself.