Deadheading or Cutting Back of Perennials and Annual Flowers
Why cut back flowers? To promote flowering, improve shape and form, make bushier plants, keep perennials compact, prevent plants from becoming leggy and to prevent pests.
Check the borders regularly and remove any flowerheads that have faded. This also prevents the plant wasting energy on seed production. Water and feed your plants to encourage a second flush of flowers. Certain plants such as Geraniums and Delphiniums can be cut back to ground level for them to flower again. Phlox can be cut to a lower set of clean leaves. With plants like Sedums and Asters you can pinch out the growing tips when they are one third of their final height. This will produce a more sturdy plant and is less prone to collapse without support.
Herbaceous perennials can be cut back from the autumn onwards. You could wait until late winter because much of the dead foliage will be well rotted and there will be less to remove than if the borders are cut back in the autumn. The cutting back of dead foliage of tender plants should be left until Spring, for example Kniphofia and Agapanthus. The old foliage protects the plant against the cold over winter. The flowering stems of Penstemons can also be reduced in Spring. Fully hardy perennials like Hostas can be cut back from the Autumn and mulched with bark or manure.
Plants with lovely seedheads such as Stipa turn a lovely brown in the Autumn. Try to retain these as long as possible, they can be cut down in Spring just before the new growth starts.
With annual plants it’s important to feed, water and deadhead them regularly. By dead-heading them you are going to get a much longer flowering period from them and your annual beds and containers will look much tidier. With Sweet Peas that have been planted from October onwards, let them over winter in cooler conditions such as a cold frame before planting out in the Spring. Then pinch out the growing point once the second pair of leaves has opened. By doing that you are encouraging more flowering stems.
Deadheading and cutting back has many benefits, the main one being bushier, healthier plants that when combined with regular feeding will give a great display of flowers. Call up to see us for more advice,
Monica Schmidt, Horticulturalist at Powerscourt Garden Pavilion
Herbaceous perennials can be cut back from the autumn onwards. You could wait until late winter because much of the dead foliage will be well rotted and there will be less to remove than if the borders are cut back in the autumn. The cutting back of dead foliage of tender plants should be left until Spring, for example Kniphofia and Agapanthus. The old foliage protects the plant against the cold over winter. The flowering stems of Penstemons can also be reduced in Spring. Fully hardy perennials like Hostas can be cut back from the Autumn and mulched with bark or manure.
Plants with lovely seedheads such as Stipa turn a lovely brown in the Autumn. Try to retain these as long as possible, they can be cut down in Spring just before the new growth starts.
With annual plants it’s important to feed, water and deadhead them regularly. By dead-heading them you are going to get a much longer flowering period from them and your annual beds and containers will look much tidier. With Sweet Peas that have been planted from October onwards, let them over winter in cooler conditions such as a cold frame before planting out in the Spring. Then pinch out the growing point once the second pair of leaves has opened. By doing that you are encouraging more flowering stems.
