Weed Control

Weeds are quite possibly the biggest irritation for gardeners, and whilst some have learned to embrace the wilder aspects of the outdoors – even incorporate them into their garden designs – for most of us, the never-ending chore of keeping the pesky – and often robust – intruders from spoiling our borders and lawns, patios and paths, is tiresome. Hoeing can be effective if weeds are caught early; if not, removing them by hand is necessary before they flower, and whilst it may be laborious, it works very well with persistence and the right tools so long as you remove the entire plant, including the roots. Even if you have the time, you may find your back and knees are less enthused by the prospect, but fortunately, some very clever and determined people have devised an array of solutions for us, some manufactured, some home-made, and some organic, so we’ve taken a look at what’s available.

Whilst killing weeds with chemicals may sound easy, doing so without harming your prized plants or, indeed, harming wildlife and pets is not so straightforward, but it’s something that has been honed by most manufacturers. If you’re looking to buy something off the shelf, you need to consider the weeds troubling you and where they are. Here are the five main types of chemical weed-killers:

Systemic Weed-killers:
These herbicides are absorbed by the leaves of the weed and travel through the entire plant, right through to the roots, killing the whole thing. They will generally take a little longer than other methods, but they are very effective and don’t linger in the soil, so any future planting will not be affected.

Contact Weed-killers:
Similar to those above, contact weed killers will generally only destroy the part of the plant they come into contact with; they may be absorbed by the entire weed but not always. Once again, the process takes time, but the soil will remain safe for further planting.

Non-selective Weed-killers:
As the name suggests, these won’t just kill weeds but everything else too, and they’ll also have an impact on the soil, so they’re not recommended for borders or lawns, but they will work well on paths and patios, and they act fast too.

Selective Weed-killers:
Predominantly used for lawns, these herbicides are a little less aggressive, designed to tackle specific plants that may spoil your cherished grass, leaving it untouched. They can be used in borders too with care.

Residual Weed-killers:
These will attack the weeds from the root as they’re designed to affect the soil, rendering it inhospitable for anything growing. Whilst they work well, their effects can last for more than a year, so planting may not be possible for quite a while. Once again, they’re ideal for patios and paths.

Whichever you choose, care should always be taken, and gloves would generally be recommended. The product instructions should be considered carefully and will advise whether further equipment is needed – watering can or sprayer – and whether the product needs to be diluted. Always check the weather forecast too, as winds may blow the product onto surrounding plants, and rain will wash it away. Catching weeds in the spring will help prevent unwanted growth in the summer, and again in autumn to capture any hardcore offenders and minimise regrowth in spring. Whilst some products start working within twenty-four hours, others can take a week or more, so patience may be needed as reapplying is not advisable until after the recommended time.

If chemical weed-killers are not for you, there are many other ways to rid yourself of the invaders if you have the right ingredients:

Lemons – covering weeds with the juice of lemons works very well, but other plants can be affected so be sure you don’t spray it around.

Vodka – ideal for broad-leaf weeds, it needs to be at least 25% proof… but if you’re a vodka drinker, don’t use your best tipple; cheap varieties will work just as well.

Sodium Tetraborate Decahydrate (better known as Borax) – very effective, but on all plants, so be careful not to go too far; it may also cause irritation to the skin, so care is needed all round.

Newspaper Mulch – when you’re done with current affairs, put your newspapers to good use by layering them in borders.

Straw – a great way to keep weeds at bay, safe to use, and it’ll also fertilise the soil as it breaks down.

Vinegar – not technically organic, but it is cheap and environmentally safe even in high concentrations.

Boiling Water – a swift option, but it will affect all plants it comes into contact with so take care not to pour on or near anything you’re wanting to survive.

Cornmeal/Polenta Gluten – several weeds including crabgrass, dandelions and chickweed, can be prevented with the use of Cornmeal gluten. Cornmeal is generally known as Polenta in the UK, but obtaining the gluten from it in this country is questionable.

Surgical Spirit – if you happen to have a bottle in your medicine cabinet, mix 2 tablespoons with 1 quart water and pour into a spray bottle; the alcohol will starve many weeds of the water they need to survive.

Baking Soda – great for weeds growing in cracks in paths and driveways; elsewhere, it may effect plants and grass you’d rather not lose.

Clove Oil – use on young weeds for best results; can also be used to repel many other garden pests without damaging your plants.

Salt – mixed with 3 parts water and sprayed directly onto the offending plants, it’ll work well without killing the inoffensive ones.

Where possible, prevention is surely better than cure, so if you’re planting a new border, you may be able to avoid the issue altogether by considering a weed-suppressant fabric. They work well if used on freshly cleared soil and will inhibit regrowth from existing weeds whilst preventing new weeds taking root. As always, there are several options, each with a number of advantages and disadvantages; are you ready?

Spun Materials: Made, usually, from plastic fibres that are bonded together to form sheets, they’re ideal long and short term but will really need a protective mulch of bark or gravel, and whilst they’re lightweight and easy to cut, cheaper versions don’t last long; tougher versions, however, can be expensive. They don’t usually fray along the cut edges, but they can fold, allowing soil to accumulate and weeds to grow. As they’re porous, they allow water through, ensuring plants survive.

Woven Materials: Plastic strands are woven into sheets and can be used temporarily or long-term on beds, borders and paths. They’re available in various grades, toughness, weight and durability, which can make them heavier than the spun materials fabrics, and any cut edges can be susceptible to fraying. Whilst they don’t require a covering of mulch or gravel, it may be preferable to the appearance of the fabric.

Plastic Sheeting: Black sheeting works well for short periods or when the appearance is less important. It’s cheap and easy to cut, but it doesn’t allow water through so rain will create puddles on the surface and the ground below will remain dry. Pricking holes will help to alleviate the problem but can also allow weeds the opportunity to grow.

Biodegradable Mulch Film: Black plastic mulch that’s made from corn starch so it’s compostable and will degrade naturally in the soil. It works well for annual weeds, but a heavier grade may be necessary to prevent perennial weeds growing. It’s not particularly durable and can degrade in 2-4 months, although heavier grades will be less fragile.

Paper Mulch and Cardboard: Ideal short-term as they’re biodegradable – paper, in particular, will degrade very quickly once in contact with the soil – but will need to be replaced frequently. Both lightweight, they’re fairly easy to use, but cardboard will need a covering of bark or compost to keep it from blowing away.

As well as the weed-suppressant fabrics, there are a few more tricks to win the weed war:

Mulching: Bark or wood chippings can be used alone or with the fabrics listed above. They will degrade naturally, so be sure to keep the mulch at a minimum depth of 10-15cm / 4-6”, and annual weeds shouldn’t cause a problem. Be mindful of woody stems as they may root too if bark or chippings are too close.

Edging Boards or Strips: Ideal for preventing grass intruding on your borders, especially the more invasive varieties like Couch Grass.

Root Barriers: Can be used to prevent the spread of invasive plans in general, not just perennial weeds. Paving slabs or corrugated sheets are great but tough fabrics can be used if you want a little flexibility.

With so many solutions available, there should come a time when weeds are just a distant memory, and we’ll look forward to the day when those pigs flap their wings… Good luck!