With spring finally on the way, it’s a great time to thin your borders and get some plants for free. Katherine Watson divides and conquers.
Winter has been remarkably tame this year, with only a few frosty mornings. The days are lengthening, but March always seems to be a long time coming. Maybe our eager anticipation and desire for light and green lengthen the time before spring is sprung and we can enjoy the delights of an emerging garden.
Spring is a great time to really get to grips with the borders. Many perennials are beginning to show now and their roots are becoming more vigorous. Weeds are taking hold too, so be ruthless for a morning and focus on making one bed beautifully weed-free.
You can divide some of your established perennials and grasses now. I remember feeling guilty one year that I hadn’t divided a congested clump of poppies in the autumn. I knew that if I did it in the spring (when I got round to that bed), it could reduce their flowering considerably. Soon after, I read a fantastic, guilt-free piece of advice from the gardener Christopher Lloyd who said: “The time to do a job is when you are in the mood to do it. The calendar is of less importance. If you wait until the ‘right time’, the chances are you’ll be thinking of other matters when that time arrives…”.
Since then I have felt less worried about moving things about and splitting things up, knowing that by-and-large, my plants will come back, albeit the following year.
Having said that, quite a few perennials and grasses can happily be divided at this time of year, redoubling favourite plants with a few swaps to spare and giving existing clumps room to breathe and regenerate. Anything that flowers after mid-June can be divided now, including the later kniphofias, asters and hemerocallis. Many ornamental grasses that have become too big for their space will also benefit. The silvery-blue oat grass Helictotrichon sempervirens is a clump-forming, spiny hummock of a grass that can grow to a metre in height if you have the space. To divide or rejuvenate, you can lift the whole thing and split it several times to re-plant. The same goes for Stipa gigantea, a delightful grass that gives height to the border.
My crocosmia are as rampant as weeds, so dividing them every other year is a must. Crocosmia make ‘chains’ of corms each year, with the later ones being dormant until divided. This is a very giving plant with a long season of interest through the different varieties. C. crocosmiiflora ‘George Davison’ flowers in early July; C. ‘Lucifer’ (pictured above) occupies August and September, and the smaller varieties – C. crocosmiiflora ‘Emily McKenzie’ and ‘Carmin Brillant’ – carry on into October. They look excellent in drifts, so you can bulk up the border through division in no time.
Inspired? Katherine’s new, six-week garden design course starts in April 2017.