Weed-busting: Protecting Your Garden Gravel & Slate Chippings

Friday 20 April 2018 15:00

Gravel and slate surfaces are a popular component for any garden and, when applied and maintained correctly, result in a beautiful, versatile and low-maintenance solution. The popularity of these surfaces continues to grow thanks to the host of benefits it provides.

What are the main benefits of Slate & Gravel surfaces?

  • With the correct installation and preparations, slate and gravel are very low-maintenance and can last for years – there is no trimming, watering or cutting required.
  • A massive variety of shapes, colours and textures are available, meaning you can be as adventurous as you like with your installation.
  • Slate and gravel gardens are highly durable and are rarely affected by rain, snow or other adverse weather conditions – with the unpredictability of British weather, gravel and slate can be huge time and money savers.

Are weeds a big problem with slate and gravel gardens?

Due to the porous and naturally laying surface of a gravel or slate garden, weeds can unfortunately find their way through and spoil your pristine surface. This is not uncommon and will affect most gravel or slate gardens without adequate preparation or maintenance.

Weeding gravel gardens

Simply follow this weed-busting guide and those pesky weeds will be a thing of the past.

How can you remove weeds from your slate and gravel surfaces?

If you are already finding weeds growing out of your gravel or slate surface, your surface may have some vulnerabilities (preventing these vulnerabilities will come later). Don’t panic, though – there are a number of easy and very affordable ways to rid your surface of weeds.

Is it okay to use weed killing chemicals on gravel or slate?

Weed killers (or Herbicides) containing glyphosate will see off the entire weed, right down to the root. These are perfectly fine to use on gravel or slate, providing the following conditions are considered:

  • Protect nearby plant life: Weed killers will see off both annual and deep-rooted garden weeds, but also nearby grass.
  • Consistent concentration: A higher concentration does not make it more effective – if your first go has been unsuccessful, try again but do not increase the concentration.
  • Children & Pets: Be aware of the potential hazards to any pets or children that may have access to your garden.
  • Allow time: Weed killers may take time to work properly. This will vary depending on weed type and what chemicals your product contains.
  • Ready-to-use or Concentrate: Some weed killers are ready to use when purchased, others come as a concentrate which require mixing at home. Consider whether convenience is worth the extra cost of ready-to-use varieties.
  • Re-application: Weed killers are not permanent and may need to be re-applied every 3-4 months if new weeds grow in place of dead ones.

Does salt scattering work with gravel and slate?

Cheaper and potentially easier than a herbicide solution is the use of salt. Salt is inexpensive and readily available at your local supermarket – when applied to plants it dehydrates them, disrupting the internal water balance, and very much kills them.

Salt, of course, doesn’t care what it kills, so be very careful when applying. We recommend using a funnel to carefully apply the solution to the areas you wish to affect. 

With gravel and slate, you are less to have desirable plants sharing the same space as the weed in your firing line, which is another benefit of the surface type.

How to use salt as a weed killer

Avoid simply scattering salt over a whole area you wish to clear out; this can easily damage surrounding vegetation and soil for a long time. Dry salt can also be redistributed by wind or rain.

Dissolve the salt in water to create a solution. Aim for a starting concentration ratio of about 3:1 in favour of water. You can then increase the salt levels as required. 

Remember to water all surrounding garden plants thoroughly afterwards, even if they seem far enough away from your gravel or slate surface.

Does boiling water work on gravel or slate? 

It probably won’t surprise you to learn boiling water will kill almost any garden plant it touches, including weeds. This is a particularly popular method because it is completely non-toxic and has no lasting chemical effects on the area where it is applied.

Killing weeds with boiling water

The method here is simple: Boil your kettle and take it outside then and carefully pour the water onto the weed from a fairly close distance. If the weed has longer roots, you may need to remove the top of the weed manually to make sure the boiling water scalds the whole plant, therefore preventing re-growth.

This is a highly cost-effective and easy-to-apply solution with far fewer chemical risks for the other plants in your garden, but if your gravel or slate area is particularly large, you may need to look at a larger scale solution like weed killers or salt.


Weeding by hand

The old-fashioned, tried and tested method of weed-busting is by hand. It can be effective in some areas, but not others. Unfortunately, manual methods are likely to disturb your gravel or slate surface, leaving it uneven or in need of additional maintenance and levelling.

Unless you’re happy with the subsequent work involved, we recommend alternative options, especially if your gravel or slate area is fairly large.

Prevent weeds from breaking out with a weed control membrane or fabric

If you are about to lay a new gravel or slate surface in your garden, the most useful method for preventing weeds is the use of a specially designed weed membrane.

What is a weed membrane?

Weed membranes are a practical, clean and easy to install, and can be very helpful for suppressing weeds of all varieties. A weed membrane is a sheet or cover that is laid over the top of the topsoil and beneath your slate, gravel or chippings, thereby blocking the emergence of weeds.

This solution is ideal for a gravel or slate surface where long-term, minimal maintenance may have been a key factor in your decision to lay such a surface in the first place.

There are some factors that should be considered when using weed membrane for weed prevention:

  • Does your gravel or slate surface include plants? It may be awkward to use weed membrane on a surface where you would like to have flowering plants requiring nutrients – you will need to create gaps to allow these through.
  • It blocks organic materials: While many weed membranes are porous and allow moisture and nutrients to penetrate, it will reduce the organic material reaching the soil for enrichment, including dead leaves.
  • It blocks sunlight: This can inhibit future plant growth
  • It can harden the surface beneath: This can also make it harder to grow plants on this surface in the future.

If you have chosen gravel or slate as a garden surface, you are probably looking at a long-term solution. If the potential effects on the surface beneath your membrane aren’t a major concern, then weed membrane is an excellent option.

Is it possible to eradicate weeds from gravel forever?

Weeds are renowned for their perseverance and it may be impossible to totally eradicate them. Some weeds can always find a way sneak through any measures you put in place; however, these measures should certainly see your weed problems greatly reduced on a long-term basis. 

We hope this has been a helpful guide for making weed-busting easy and hassle, and we wish you the best of luck and success in your weed-busting endeavours.

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