Divide and Conquer – rejuvenating perennials and bulbs

Divide the clump
Divide the clump. Photo: The English Garden

The perennial problem.
As perennial plants mature they can start to look congested and tatty, fighting for space with their neighbours and dying out in the centre whilst all the healthy growth is around the outside.   Most perennials benefit from being lifted and divided every three or four years.  As well as rejuvenating the plants it’s a great way to increase your stock.

Divide the clump
Divide the clump 2. Photo: Caseys Outdoor

When to divide
The old-fashioned rule is if it flowers before Midsummer’s Day you should divide it in autumn, and if it flowers after Midsummer’s Day you should divide in spring.  There are exceptions, but generally you need to divide when there are clusters of new leaves pushing through the soil (if you wait until the leaves have opened out there’s a bigger area for water loss and your new plants are more likely to wilt and take longer to establish)

How to divide

  • Arm yourself with a couple of garden forks, a spade and a plastic sheet
  • Carefully dig out the clump you want to divide and lift it onto the plastic sheet. If the clump is too heavy to lift use the spade to slice sections out of it
  • Split the clump into several pieces. You might be able to pull the clump apart with your hands or with the garden forks, but woody rootstocks will require a knife or saw. Each piece needs its own shoots and roots
  • Replant the best bits at the same depth as they were before, after working some compost and slow-release fertiliser into the ground.Water well and remember to keep watering until the roots are well-established
Dividing bulbs
Dividing bulbs. Photo: The English Garden

Dividing bulbs
Bulbs need to be divided for similar reasons. Many are excellent at multiplying themselves and, over time, clumps become overcrowded and flowering declines because of the heavy competition for nutrients.  Snowdrops and Winter Aconites in particular must be divided ‘in the green’ – straight after flowering, and most other bulbs can also be dealt with whilst the leaves are still growing vigorously.  CrocusDaffodils and Grape Hyacinths will all divide well in March.

  • Lever the clump out and gently rock and twist the bulbs back and forth until they separate.
  • Don’t allow the bulbs to dry out during transplantation – cover them with wet newspaper while you work
  • Replant clumps into well-prepared and fertilised soil at the appropriate depth.
  • Mulch and water

Beautiful bulbs for spring colour

Bulbs are amongst the easiest and most rewarding garden plants to grow. Get them in the ground or in pots now so you can enjoy a cheerful parade of flowers going through from January to late spring.

Planting Bulbs
Photo: Wyevale Garden Centres

Most bulbs can be planted now – Snowdrops, Daffodils, Hyacinths, Crocuses, Fritillaries, Iris, Muscari, Anemones, Scillas, Lillies, Alliums and Crocosmias, – but leave tulips until November. Hardy bulbs can be left undisturbed in the ground and will multiply over time. Only plant non-frost-hardy types if you can face the bother of lifting and storing them, or you’re happy to risk some losses.

The main rule with bulbs is to think big and plant for impact – if you think you need 20, plant 40!  And in pots squeeze as many as you can get in without them touching. Plant in groups rather than in straight rows, and if planting a small number of bulbs choose an odd number for a more natural look. You’re unlikely to spend much time sitting out in the garden in February, so make sure you site them where you can see them from your window.

Try planting drifts in the border, or under deciduous trees for a carpet of colour in spring before the trees comes into leaf. Bulbs grown in the lawn will have to be mown around until 6 weeks after flowering. Bulbs in large containers can be planted in layers for a succession of blooms – Snowdrops in January give way to Daffodils and Tulips in March and April, followed by purple Alliums in May.

Bulbs in pot
Photo: https://bulbsandbeyond.com

It’s important to bury them deeply enough – if you aim for three times their own depth you won’t go far wrong. Too shallow and they’re more likely to get eaten by pests. Too deep and they may not reach the surface. A bulb-planting tool and a good garden kneeler are worth their weight in gold if you have lots to plant.