Get the best from your borders
For many gardeners, their carefully planned herbaceous borders are the climax of gardening achievement — with height, flower power, scent and colour vying for attention. Bees, butterflies and moths are busy foraging for nectar among the blossoms. It adds up to a beautiful sight — the epitome of flower gardening — but one that requires constant help and intervention, even in mid-performance.
Happily, most midsummer tasks are enjoyable and allow us to appreciate our achievements while tending to the border’s requirements; ensuring that it doesn’t run out of steam before season’s end and planning ahead for next year.
Many herbaceous plants have a healthy appetite. When preparing a border, you should add an undersoil seam of well-rotted manure to the space, deep enough so that it doesn’t burn the roots of the newbies.
Then, each spring, a good feed with chicken manure or slow-release pellets will ensure they have supplementary feed for the summer display.
If they look a bit listless even with all of that, give them a boost with a mid-performance liquid feed. This could be a seaweed feed or a high potash feed, such as tomato feed to boost flowering.
Regular watering during dry weather is essential.
There are lots of plants vying for a drink and, while they won’t dry out as quickly as potted plants, they can still suffer, especially less mature plants.
A daily patrol to deadhead can reap huge rewards.
And while you’re at it, foxglove spikes and poppies can be cut down (unless you are saving them for seed). Earlier flowering plants such as lupins can have finished flowering stems removed.
If you’ve planted extremely densely, your border won’t need much weeding. However, keep an eye on rogue plants — a weekly tugging out of unwanted weeds is part of the plan.
Some taller plants, such as Meadow Rue (thalictrum) and dahlias, may need a bit of support.
It’s common to stake at the beginning of the season but I tend to adopt a wait-andsee approach. If I can get them to stand tall without any support, all the better.
However, there are some plants — such as the valerian — which now need something to lean on.
Observation is key: what’s working, what’s not? Some plants are natural invaders and will take over if allowed — lysimachia is one such offender. Is she elbowing out her neighbours?
It’s a good time to tag plants that will need lifting and dividing in autumn or spring.
You might want to do this to increase stock of a favourite plant or to rejuvenate an older one.
Very mature herbaceous plants tend to start to grow outwards in concentric circles — like ripples in a pond — leaving a bare centre.
Leave a marker in the ground beside these specimens so that, come autumn, you’ll remember which ones need doing.
Since my visit to the Botanics, I’ve been spending time gazing at my herbaceous planting at home and analysing what I’ll change next year.
I have lots of purples and yellows, but I think that red astilbe in the shady corner is jarring with the colour scheme. I can also see where it’s going to be a bit dull later in the summer, so I might get some late summer colour such as asters, heleniums and rudbeckias to keep the showing going until early autumn.
It’s a time to imagine other possibilities. Maybe is it time to tear up your own rule book?
Have you spotted something in other gardens that you’d like? Take photographs now — it’s all to easy to forget once it dies down. Already I’ve made a note to add some zing! To start with I’ll use geums such as ‘Totally Tangerine’ which will go to work early in the season.
Tall eremurus ‘Pinocchio’ bursting through the sedate planting will add excitement. I’m going to include some orange Turk’s Cap lilies for mid-summer madness and maybe finish the season with some vivid crocosmia ‘Emily McKenzie’. Never stop dreaming!
SUMMER COLOUR: Turk’s Cap lilies will brighten things up as we move into July and August