how to stop weeds growing through decking

How to stop weeds growing through decking

Just on the glyphosate vs vinegar question: acetic acid is a herbicide. Household vinegar is usually a fairly weak solution of acetic acid. Glyphosate is thought to be potentially carcinogenic but in tests it is LESS toxic to animals than acetic acid (less likely to kill you immediately if you drink a glass of it). Vinegar is less effective as a herbicide, therefore to get the same effect you will have to use more of it and anyway, it’s effectiveness against a perennial weed such as couch grass is doubtful. I don’t know whether vinegar or glyphosate is more harmful to bees and pollinators but to your soil and it’s ecosystem, by the time you’ve actually had an impact on the couch grass, the vinegar is likely to do more harm.

raisingirl East Devon, on the Edge of Exmoor. Posts: 5,022

I’m spending today digging out the roots of couch grass, ground elder and an invasive euphorbia from one of my bordersd, B3. It’s the only way to be rid of them completely and safely (both for myself and the environment.) Not so easy to do that under decking though.

wild edges The north west of south east Wales Posts: 6,807

The weed killer was used as the garden was completely ‘reset’ last year. It was a complete removal of unkept raised beds with numerous bad plants in, and a plethora of weeds, old lumps of concrete patio/pathway, 10 different types of grass, and about a 12 inch slope taken out.

All replaced, with a new decking area built on weed netting, plastic grids, shingle stone and a wooden support beams, and a new shed. The weed netting/grids/shingle stone is to improve rain soakaway, and these are all permeable materials for rainwater, which concrete and polythene weed barriers are not.

From what I’ve read on weed killers, most of them don’t work well against grass, but I have read several suggestions on using Vinegar, which is much more friendly to the environment. I hope to raid a nearby supermarket later to try this out

wild edges The north west of south east Wales Posts: 6,807

Either way, couch grass is one of those weeds that WILL come back, unless you can eradicate it entirely from your own and your neighbours’ borders. So you either need to accept you are going to have to kill all the invertebrates and soil bacteria in the vicinity every year in perpetuity, or bite the bullet and take up enough of the decking to rake out the shingle and lay some heavy duty black polythene instead.

How to stop weeds growing through decking

You can also use rocks, bricks or anything heavy to keep everything close to the ground. Sand is heavy and offers drainage so you will not get puddles and a lot of runoff when it rains.

Not many people think about weeds when they install their decking only to discover a few months later that green shoots start to pop up.

Using salt or strong weed killer can harm the local wildlife, ruin your soil and could make your pet sick if they digest it.

Like all weed solutions, there is the chemical version that will slowly destroy the soil around your decking project or the safer methods.

Fitting Your Weed Barrier

You must not use plastic sheeting because you will find that rainwater puddles and becomes stagnant.

You can remove a section of the boards and gently spread it underneath.

Some installers will cover the area in a salt mix or use enough weed killer to destroy the soil for many years.

Installing A Weed Barrier

I then cover the weed barrier with sharp sand so there is no room for weeds to grow and take hold underneath the weed barrier.

If your decking has already been installed then you can still use a weed barrier.