How to control weeds
Weeding is one of the most maligned jobs in the garden, but it’s one of the most important. Weeds compete for nutrients and can hugely impact the health of your plants and crops but there are many ways that we can make life easier for ourselves and cut down on the amount of work needed to keep the garden weed-free.
Prepare new ground thoroughly before planting
Make sure that any perennial weed roots such as Dock Leaves, Dandelions and Thistles are removed as new areas are prepared for planting. These should not be composted but put out with your household waste or dried out and added to the bonfire. Composting them or chopping them up will only make new plants when the compost is spread.
Hoeing is a very useful form of weed control in the vegetable garden. Regular hoeing between rows will kill annual weeds and keep on top of perennial weeds as they regrow. Choose a dry day when the soil surface is dry and hoe as often as you can.
Use a ground cover material
Areas that are to be newly planted can be covered with a permeable membrane to act as ground cover material, once the ground has been thoroughly prepared. This will allow water in but keep the light out and stop the majority of weeds from growing. Planting can be done through the membrane by cutting a cross in it and to finish, the area can be covered with bark or gravel.
Cover unwanted ground on the vegetable garden
Large areas of ground that are not needed on the allotment can be covered with black polythene sheeting, old carpet or ground cover material. This will smother weeds and stop them growing until you are ready to cultivate the ground. If you rent an allotment, be sure to seek permission before doing this – some groups don’t allow it.
Mulching acts as a weed suppressant and, due to the crumbly texture that it creates on the soil surface, makes any weeds much easier to remove, but it has a number of other benefits too:
- It acts as a soil conditioner. The worms and weather will take the mulch into the soil, adding to the amount of organic matter and nutrients available to your plants.
- If applied after large amounts of rain, for example in spring, mulch will help to keep moisture in the soil for longer and cut down on watering through any dry weather.
- It’s a great way of recycling if you make your own compost or have a good supply of well-rotted farm yard or stable manure.
Use ground cover plants
There are many plants that can be used to cover the ground and act as weed suppressants in areas that you may not want to garden often. These are perennials and shrubs that form an attractive carpet which suppress germination and development of weed seeds and eliminate the need for weed control measures. Examples of these include Hebe ‘Pagei’; variegated Euphorbia; dark purple-flowered Vinca (Periwinkle) and Bergenia (Elephant’s Ears) ‘Silberlicht’.
Start a compost heap
By starting a compost heap, you will be able to make your own rotted compost to use as mulch on your borders. It’s also a great way to recycle garden waste and saves taking it to your local ‘green skip’. Remember not to add flowering weeds to your heap, as the seeds may germinate in the compost when it has been spread on the garden.
Options for an organic garden
If you have an organic garden, weeds can be controlled without resorting to chemicals. Some deeply rooted weeds might be more difficult to eradicate but not impossible. All of the above methods are suitable for use in an organic garden but other options include:
- Hand pulling or weeding with a fork
- Using a weed knife (which has a hooked end) between paving slabs and along paths edges
- Repeated cutting will weaken and can kill some weeds, but this might take several years in large weedy areas
- Using a flame gun to scorch of weeds between paving slabs and on driveways
Weed killer (herbicide) can be used with care in your garden. There are different types of herbicides for use in different situations.
- Selective weed killers, such as lawn weed killer, are used to control broad leaved weeds on lawns without harming the grass.
- Contact weed killers will kill all plants that they are applied to. In ideal conditions, results can be seen within a day but they may not kill weed roots so perennial weeds such as Docks and Dandelions may regrow.
- Systemic weed killers will also kill all plants that they are applied to. Usually, they are slower acting than contact weed killers but will kill roots as well as top growth. Roundup is a systemic herbicide.
- You can use a residual weedkiller, such as Pathclear, on drives, gravelled areas, paths and waste ground where you do not want to replant. Residual weed killer usually contains a contact weed killer as well as a residual one which will prevent new weeds from germinating. They usually stay active for three months in the soil.
Weed killers that are available as ‘ready to use’ (RTU) have been diluted and can be used straight away, or for larger areas concentrates can be purchased to dilute with water in a sprayer or watering can.
Tips for using weed killers
- Choose a dry day with no wind. Make sure that the weeds are dry before you spray so that the solution sticks to the leaves.
- Try to spray early in the day or last thing in the evening when there are fewer insects on the wing.
- Choose the right spray for the job.
- There is no need to drench the weeds – just spray a little on each one and it will work. Drenching the weeds or using ‘double strength’ is a waste of money!
- If you have a large area to spray, invest in a small sprayer so that the correct amount can be applied. Using a watering can is less economical.
- Make sure you mark your sprayer or watering can ‘WEED KILLER ONLY’ to prevent them being used for pesticides or to water plants.
- Buy little and often and always store herbicides responsibly.