Daisy, common daisy

(Bellis perennis) Daisies, or common daisies, are perennial plants regarded as weeds when they take over the garden. They are usually more of a problem when growing in the lawn.

What are Daisies?

The daisy family (Asteraceae or Compositae as it used to be named) is a huge family of flowering plants, including artichokes, Calendula (pot marigold), chamomile, Echinacea, Michaelmas daisy and sunflower.

The common daisy or English daisy (Bellis perennis), usually just referred to as “daisy”, is available as relatively large-flowered varieties grown as winter and spring bedding plants. The species is a British native wildflower, and many people will remember making daisy chains of its flowers when young. But when it seeds itself and grows all over the garden, it is regarded as a weed.

Daisies are perennial plants that will grow in just about any part of the garden. They usually become more of a problem when they establish in the lawn – their low-growing rosettes of leaves covering and smothering the surrounding grass, causing bare patches.

These evergreens remain throughout the year and each plant is capable of producing numerous seeds. These can remain dormant in the ground for several years. And as “One year’s seeding means seven years weeding”, allowing plants to flower and produce seeds, means several years of trying to control and remove it.

Where do they grow?

Beds
Borders
Lawns
Gravel paths
Between paving slabs
Waste or uncultivated ground

Appearance

The common daisy is an evergreen perennial plants, producing rosettes of small, deep or medium green, rounded or spoon-shaped leaves.

The typical white daisy flowers with a yellow centre are produced mainly in summer, but they can have a very long flowering period and can even produce a few flowers in winter. Plants can produce numerous seeds, helping to spread it further afield.

How to control daisies

As with most perennial weeds, don’t allow daisies to become established, and certainly don’t allow them to flower and produce seeds. This will make it more difficult, and more time consuming, to fully control. Early identification and eradication is important to stop them taking over the garden.

Natural control

Digging out the plants is a relatively quick – although not necessarily easy – way of getting rid of daisies. A fork and hand fork are usually better tools than a spade and trowel.

Regularly hoeing seedlings and young plants as soon as you see them is the quickest and easiest method of control. The aim of hoeing is to sever the weed stems at or just below ground level, cutting the top growth from its roots. A sharp hoe blade will make this even quicker and easier, so always sharpen the hoe blade before using it. Hoeing on a warm and/or windy day will mean plants quickly dehydrate and die.

Digging out the plants when they are more established is more time consuming and more difficult – especially where they’re growing among wanted plants.

Flame guns and weeders that use an electric current are also effective in some locations.

Covering bare soil with weed-control membrane (landscape fabric) or even thick black polythene will exclude light and prevent seeds germinating. As will mulching the soil with organic matter, such as a bark mulch. For mulches to work properly, they need to be a minimum of 5cm (2in) thick, but 7.5cm (3in) deep works better.

In lawns, daisies will need digging out before they start spreading, and smothering and killing the surrounding grass. A trowel is the best tool to use in this situation.

Weedkillers

There are a number of weed control options available to treat sow thistles. In addition to traditional weedkillers there are now also a range of more natural alternatives.

Any weedkiller can be used to control and kill daisies in beds, borders, waste ground and on paths. Those marketed as “fast acting” are contact weedkillers – killing or damaging the plant tissue they are sprayed onto or make contact with. These tend to be based on “naturally-occurring” active ingredients, such as acetic acid and natural fatty acids. Systemic weedkillers that also kill the roots can also be used. To ensure the weedkiller works effectively:

Spray the leaves when the daisies are growing actively; this is mainly from March/April to September/October. Contact weedkillers will have some effect if used during the colder weather in winter.
The larger the leaf area present, the greater the amount of weedkiller that can be absorbed. So don’t bother spraying when the growth first emerges through the soil – wait until the leaves grow larger.
Use a fine spray to thoroughly coat the leaves in small droplets.
During the summer, spray in the evening to prevent the spray evaporating and to give maximum time for the spray to be absorbed. In spring or if overnight dew is forecast, spray earlier in the day to allow the spray to dry before dew falls.

Most contact weedkillers are total weedkillers – that is they will damage or kill any plants whose leaves they are sprayed on. Make sure you keep the spray off wanted plants – including lawns – and, if necessary protect plants by covering with polythene or similar when spraying. Gel products, which is dabbed onto, and sticks to, the weed leaves, may be a better option when trying to treat daisies growing close to wanted plants, where drift of the spray would damage them. In lawns, spray plants with a good lawn weedkiller. Not all weedkillers are as effective as others. Those containing clopyralid are usually most effective. Make sure the lawn is well fed and not cut too short to help the grass out-compete daisies and other lawn weeds.

Use weedkillers safely. Always read the label and product information before use.

Prevention

Don’t allow plants to flower and set seed. Although this is pretty easy in your garden, it’s more difficult to stop the seeds blowing in from a neighbour’s garden, any surrounding fields and waste ground and even further afield.

Plants arising from seeds of ornamental varieties of daisies used as winter and spring bedding plants will also revert back to the common species, so deadhead plants to prevent them setting seeds.