Last Updated on 08/07/2023 by Barney
Laying slate chippings in your garden is not a skilled job, it just requires planning, a bit of muscle power and the right ground preparation. Once complete, they will provide that low maintenance garden we all dream of!
As a professional garden with over 20 years experience I have moved and laid many tonnes of slate chippings and decorative aggregates (just ask my back).
Follow my guide for step by step instructions to lay slate chippings in the garden. Be it for a decorative topping, a path, around attractive focal points, free standing water features and planting areas.
Hopefully you’ll find a few tips of the trade that have helped me discover how to make this landscaping project hassle free and easy to do.
Time needed: 4 hours
Laying Slate Chippings in 6 Easy Steps
- Have the right tools
A wheelbarrow, weed membrane & shovel
- Clear the ground of weeds and debris
Before laying the weed membrane and chippings clear all perennial weeds and large stones
- Calculate the quantity of slate chippings needed
To estimate the quantity needed (length x width x depth)
- Choose the chippings size & colour
- Install a weed membrane
Use a decent heavy duty membrane and fix with pegs before laying the chippings
- Lay the slate chippings
Use the back of a shovel or a rake to level the slate
1. ) Tools needed for the perfect finish
Heavy Duty Wheelbarrow
Lugging around 25kg bags of slate chippings can be back breaking work. Use a sturdy wheelbarrow, your back will thank you for it.
If having a large bulk bag of slate chippings delivered then a wheelbarrow is an must when moving the chippings from the front to the rear of the house (see my top tip on bulk bags further down)
Useful for cutting open the heavy duty polythene bags or the bulk bag
Wide mouthed shovel
Extremely useful for shoveling garden slate chippings from a wheelbarrow or hard base. A garden spade will not fit many slate chippings on it and about as useful as a chocolate teapot!
Slate chippings and other quarried stones often arrive covered in stone dust from the quarry, so for that professional finish, give them a rinse once laid (or wait for a heavy downpour).
Weeds will want to grow up through slate chippings so installing a quality weed membrane from the beginning will prevent this from happening.
String Line & Pegs
Useful for creating straight lines when constructing a slate chipping path.
2.) Ground preparation
Slate is great when used as a mulch around planting and beneath vegetation. It also works wonderfully at retaining moisture.
Step 1. If the flower bed is empty simply remove all weeds. Level as much as possible with a soil rake.
Step 2. Install a tough , water permeable weed membrane and peg down.
Step 3.) Carry out new planting through the weed membrane by cutting X’s with a sharp knife and folding back the membrane.
Step 4.) Shovel the slate chippings into place and level with a rake.
Laying the membrane on an already planted bed is going to require extra time as the membrane is tricky to cut around plants. However, do spend the time on doing this. Not doing so could leave you with dirty slate chippings and unwanted weeds (no one wants that)
Laying a slate chippings path
Laying a slate chipping path that will last requires muscle power.
Step 1. To make perfect straight edged use string and pegs to mark out the new path.
Step 2. Excavate to a depth of approx 12cm.
Step 3. Install edging of choice to retain the slate chipping. This can be pre treated timber, steel edging, decorative brick, concrete or a discreet plastic edging
Step 4. Lay approx 100mm of MOT Type 1 and compact down with a hired ‘whacker plate’ or other flattening tool (back of a sledge hammer works well for small paths)
Step 5. Tip slate chippings directly onto the prepared base and rake level.
3.) Calculate quantity of slate chipping to buy
Slate chippings are best when laid to a approx depth of 5 – 6cm. Getting the correct quantity from the start is straight forward.
To calculate :
Length to be covered 2 metres x width 1 metre x depth of slate chippings
2 x 1 x 0.06 = 0.12 cubic metres.
If buying from a DIY or garden centre in individual bags, it should state the coverage each bag will give.
If buying in bulk bags (1 tonne) ask the supplier what coverage you will get.
4.) Choosing Slate Chippings
Not all slate chippings are equal and can be purchased in colourful shades and sizes.
Years ago it was only plum coloured slate chippings, however, there is now grey, green, plum and blue slate.
Sizes range from slate mini mulch chippings (fine grained type 5 – 14mm in size), this size works great as a flower bed mulch, to 40mm. Larger sizes are also available, sold as paddle stones. Paddle stones are great to create attractive focal points around water features and water gardens.
20mm slate chippings being the most common.
If placing around a freestanding water feature I would recommend the larger sizes. This makes it easier to access the pump etc
Consider the colour slate chipping turn when wet. Does this colour go with your outdoor landscaping project? For instance, something like a charcoal slate chippings in your garden turn a wonderful darker shade when wet but is this too dark for a shaded corner?
Online suppliers and garden centres are happy to provide samples to take away to help in choosing the best for your garden.
5.) Lay a Weed Resistant Membrane
I strongly advise a weed suppressing membrane is laid beneath slate chippings anytime the slate chippings are going to be in direct contact with garden soil.
This prevents weed germination from happening (no one wants more weeds)
Laying the membrane is as simple as cutting to size and securing down with pegs.
More info on this can be found on our best weed membranes page.
6.) Laying the Slate Chippings
Once the weed membrane is in place and held down securely with pegs tip the wheelbarrow, or empty the bags directly onto the area.
Finally spread & level with a soil rake or end of a wide mouth shovel.
Frequently asked Questions
Yes . Garden slate chippings are environmentally friendly as they are recycled material from the roofing and slate industry .
Slate will not change the soils pH and will not damage lime hating plants.
Edging slate chippings depends on the situation.If creating a path then yes a retaining edge is advised.
If using on a flower bed then consider what will retain the chippings. Remember, ideally they need to be 5 – 6cm deep. Not retaining them could mean your chippings spill over onto the lawn & patio etc.
Yes. There are plenty of low maintenance plants that look fab when planted in slate.
Yes. Using this decorative aggregate on plant pots will perform 2 functions. Not only will it make pots look ‘posh’ but also help in cooling soil in hot weather, reducing evaporation. Less watering! You can not argue with that.
A light grey will go along way to lightening darker areas of the garden. Using a lighter tone of slate will turn a dingy backyard into one that feels light, spacey and modern.
To reduce weed germination a highly durable membrane is essential to prevent weeds, even if laying over block paving.
A couple of methods I have used in the past.
Garden Sieve and Hose Method:
This works best if there is a relatively small quantity of chippings to be cleaned.
Old Wheel Barrow and Hose Method.
If there is a large quantity to be cleaned then I recommend this method. Simply make some holes in the bottom of and old wheelbarrow to let the water drain and use a hosepipe to wash them down
The Bottom Line
As you can see, there is nothing to laying slate chippings & decorative aggregates in the garden. Just a bit of planning and the right tools. Pick a good day with no adverse weather due.
This is a physical landscaping project and better done with fresh legs & arms. Not great to attempt after a 40 minute spin session.
Not convinced? If you are looking for a lighter to handle mulch then you could consider bark chippings as an attractive alternative.