Creating a Beautiful Tiered Garden From a Boring New Build Slope

In early 2021 myself and my wife bought our first (and hopefully only) house. It was a new build on a private cul-de-sac of 7 other houses. New Build houses, especially in the UK, have a reputation for poor quality gardens and our house was no exception. Instead of settling for less though and with both of us very much into gardening we challenged ourselves to turn this blank canvas of uneven, sloping, clay soil into a very personal inspired landscaped garden.

I'll cover the other parts of our garden at the end, but this Instructable is on our favourite part of the garden that's been transformed from boring slope to a two tier with a retaining wall and finished off with lots of interesting plants!

See pictures for what we started with!

Supplies

Lots of tools required for this mammoth task, we tried to do it on a budget though, with the Micro Digger only hired for 3 days, a skip for a week, borrowing tools and a LOT of manual labour, with help from friends too!

Tools required:

Building Spray Marker Can

Shovel (more the better)

Flat Spade

Pickaxe/Mattock

Wheelbarrow

Mallet

Soil Rake

Stanley Knife

Handheld Drill/Screwdriver

Rubble tub (Flexible bucket with handles)

Builders String

Spirit Level

Hand Clamps

Adjustable Spanner

Heavy Duty Scissors

Materials:

Postcrete 20KG x 5 (around 10KG per post)

Fence Posts

M8 Coach Bolts

Felt Nails/Tacks

Wood Boards

Building Sand

Stepping Stones (of your choice)

Patio Slabs (of same type/colour if extending patio)

Broken up patio slabs (for fence post bases)

Grass Seed (We chose a slow grow lazy variety)

Weed Membrane Roll

Wood Protection Oil

Solar Powered Strip Lighting (Optional)

Step 1: Digging Out the Lower Tier

Fast forward to June 2022, we had an idea in our head what we wanted to do to create the tiered part of our garden using the last 3rd of our Garden. Our first born son was also 7 months old and we wanted to get the garden into a good place for when he was walking (turns out that was only 3 months later!). We hired a 'Micro Digger' for 3 days (Friday morning delivery for Monday Morning collection) at a cost of around £350. I'm not qualified in any shape or form to use a Micro Digger (all you need is a driving licence), I'm a Senior IT Engineer by trade, but our friendly neighbor, Billy, had done similar to his garden recently, so was willing to teach me on the Friday evening and Saturday Morning, as well as give me a hand operating it, without him it may have taken a lot longer to get to grips! See videos..

We also hired a skip for a week (friday to friday) at a cost of around £265. Weird how skips cost the same for a month as they do for a day..! This was purely to put all the unwanted clay soil into, we literally maxed it out and it was so heavy the skip collection Truck struggled to lift it back on!

Before you even start digging though, exciting as Micro Diggers are, make sure you have a plan and have marked out where you want to dig with a spray marker can. This doesn't have to be exact, ours did change a little, but roughly so that the digger is doing the most part of the dirt removal and not you with a spade/pickaxe. Making a dent in clay soil by hand is VERY hard work as I found out before even ordering the Micro Digger, it's heavy, dense and sticky.

The technique of what to dig first was more difficult than I first envisioned but basically required me to dig from the lowest point by the fence first, then work backwards towards the house so the digger always had a platform to dig from.

Despite the Micro Digger doing 90% of the work, there was still parts that could only be done by hand, such as leveling the ground and making the wall edges straight, this was mostly done with the Flat Spade & Pickaxe. This just gave a nicer finish to the overall look of the area before beginning on the retaining wall.

Step 2: Building the Retaining Wall

Again I enlisted help for building this retaining wall, my neighbour, Billy, pointed out before we even started that having right angles to make the wall a U shape would drastically improve its strength. This sounded logical to me and then my dad helped me actually build the retaining wall with the following steps:

1) Mark out and then dig out holes for each fence post with a Flat Spade, allowing at least 5-10cm gap on each side of post. This part was surprisingly easy, as one benefit of clay soil is that it holds its shape after you've dug in. Make sure you leave enough of a gap behind the post holes/between the posts and the dirt, for your Wood Boards to fit afterwards.

2) Probably the most important step, but do note this is not how the professionals do it, but it worked well for us. Using broken pieces of patio slabs we had lying around, lay a piece flat in the hole you just made and then put fence post in on top. Tap down on top of fence post lightly with a mallet. Test your post is level on top and sides with a spirit level, if it is not, remove fence post and adjust slab in bottom of hole appropriately. This process is time consuming, but important. Once you're happy it's as level as it can be, fill hole with more excess rubble/slabs to support the post pre-postcrete.

3) Once your fence post is in place in the hole, water the bottom with a watering can/hose pipe with FRESH water (not rainwater). Now add enough postcrete (about half a 20KG bag for us) to fill the hole then water in thoroughly. Drying time is around 10 minutes, but we left them for at least 30 minutes before touching the post. Again, this is best done on a warm day.

4) Repeat Step 2-3 for every post, 9 times in our case. Don't worry about the finish height of each post, we came to the conclusion it was a lot easier to cut down the size afterwards. See pictures for the process, I've ordered them best I can!

5) Cut your Wood Boards to size for where they're going, then use hand clamp(s) to temporarily hold in place against the posts.

6) Drill through the post and into the board with a wood drill bit that is exactly M8 (same as coach bolts), if any smaller or larger than the coach bolts, this won't work.

7) Tap coach bolts through the hole you just made with a mallet, then screw in the nut on the other side with a spanner. The coach bolt won't spin on its own whilst you tighten, if you used the right size drill bit.

8) Repeat Steps 5-7 until your retaining wall is fully populated. See pictures.

9) Chop excess wood off fence posts with a hand saw. See Pictures.

10) If you want to, like us, use a sharp hand saw to cut the boards into a curve, going with the slope for a nice effect. See Pictures.

11) This step is optional but recommended for longevity, oil your entire retaining wall with 2 or 3 layers of wood protection oil. Again, this is best done on a warm day, allow 30 mins drying time between layers.

12) Before filling the dirt in the gaps between the back of your retaining wall, it's important to line it with polythene sheeting (aka dust sheets) to stop the wood rotting. Do this by cutting the sheets to size with scissors. Attach to the back of the retaining wall with tacks and to the top of the fence posts (reason why in next step).

13) Cut your coping wood to size then lay flat on top of desired fence posts, making sure your polythene sheeting, from previous step, is tucked in between. Screw in wood screws from the top with your drill with Phillips bit. See Pictures.

14) Fill in gaps behind your retaining wall with 20mm gravel and or rubble first, to improve drainage. Then fill the rest with dirt leftover from your digging, up to desired level. Top tip, plants that require deep roots, such as Geraniums, will love this spot.

Your retaining wall should be done now, but the above steps were time consuming, even with three of us, it took most of a weekend and that was with my dad's experience (built a lot of decks in his time).

Step 3: Patio Extension & Stepping Stones

We decided to slightly increase the size of our patio to make our path down the eventual stepping stones flow nicer. We only needed ten paving slabs to do this and some concrete so total cost was only around £200. I'd never done concrete mixing before so enlisted my dad's help and mixer for this task. Before the mixing and placing could begin though, I had to use the pickaxe to dig a shallow hole twice the depth of the paving slabs.

We didn't want to concrete in our stepping stones, reasoning being to be more eco-friendly but also future proofing. Make sure you always have a spare or two of your chosen stepping stone for future replacements. As seen in the photos, I just dug shallow holes where each stepping stone was going and filled with building sand.

This method took a fair amount of adjustment to get the stepping stones stable, around 10-15 minutes per stepping stone, but will be easy to fix issues in future.

Almost a year later, even after a harsh winter, none of the stepping stones have moved, if anything they've sunk in and become more solid.

After all the stepping stones were in, I bought lots of big bags of Multi Purpose Compost to spread around the area. This would introduce nutrients to the soil and make it easier for seeds (mainly grass seed, using the soil rake) or young plants to establish.

Step 4: Planting

The part my wife, Natasha, was most looking forward to, I left her to mostly pick what she wanted for this part of the garden, with lots of visits to different garden centres at weekends!

Down the sloping side by the deck, we wanted to create a natural screen that would provide privacy and shelter when using the lower tier. My wife was also keen to create some sensory elements to stimulate interest in plants for our little boy so for this area we used grasses. Miscanthus grass would provide the height for the screen element and dotted in between we used Stipa Tenuissima, commonly known as ponytail grass, to bring softness to the lines of the wall and add touchable texture. We also planted a couple of pink Echinacea to encourage the bees and bring some colour to that area. At the very bottom we have a Choisya, or orange blossom shrub, which sits directly behind our bench and once fully grown will fill the air with a natural orange scent.

For the wall area alongside the patio, we focused on low growing plants that would soften the harsh edges of the wall. Dwarf Japanese Anenome's and Geraniums were the key feature here, ranging in different shades of pinks and purples. These all have beautiful green foliage and flower at different points throughout spring, summer and some (in the case of the anemone's) even into autumn.

As we near the path down into the lower tier, the garden turns into a more woodland feel as this area gets mostly shade during the day. We planted some deep red Heucheras and a few varieties of ferns as more shade loving plants. My wife is a big fan of flowers though, so we didn't leave this area without some floral elements. We included later flowering tall anemones in white and light purple and some woodland anemone's which are more low growing. Another great splash of colour in spring is the Brunnera which has beautiful dainty blue flowers and really pops next to the green of the ferns. As you can see in the pictures we also scattered some logs in amongst the plants to enhance the woodland feel and provide areas for nature to create their homes. All of this planting was based on making the most of texture and almost creating a little adventure down the path for our little boy.

Finally as we get to the end of the path and into the lower tier we have two stunning climbing Hydrangeas against the fence which are a great feature and provide shelter for the birds. We have also just added a Japanese snowball shrub which is fairly rare but creates glorious white globes of flowers, so this will be a real focal point of the garden.

As a final note, you may notice we've mainly chosen hardy perennial plants, what with UK winters being extreme cold of late (-14C last December) and Summers much hotter recently (41C last July!), we wanted plants we didn't have to worry about, that only need watering once a week in dry spells and can just be cut/pruned back and left in the winter.

Step 5: Finishing Touches

After the first lot of planting was done, we decided to put our Pallet bench, that we built ourselves years ago, down the bottom as it matched the retaining wall wood aesthetic. To do this and keep it weed free around the bench, I put down Weed membrane in a triangle shape and then covered in decorative bark to keep the natural look of the area.

Step 6: Rest of the Garden

The rest of the garden is split up into two sections, a big deck and a grassy area with a weeping Cherry blossom tree in the middle.

My dad built the deck, with digging help from myself and a friend, and laid out a small turf area adjacent, in September 2021. Initially he built us a raised flower bed along our fence line at the back of the decking, using some of the leftover dirt to fill.

Unfortunately, around a year after it was all built, we noticed the sheer weight of the soil (half clay) and the fact it was all built on a slope, was actually pushing against our fence posts significantly and the longer we left it, the worse it would get. Subsidence is annoying. After a lot of thinking/panic I decided to turn a negative into a positive. All the soil had to come out, but for a while I'd been wanting to increase my vegetable growing capacity, so I bought three deep raised beds, 180cm x 90cm x 45cm, (did some rough volumetric math to figure out how much soil there was to move into them) and built them in a U shape on the grass area so as not to disturb our Weeping Cherry Blossom tree. I lined them with some polythene sheeting and some large head nails/tacks then began the arduous task of shifting all the dirt into them from the falling apart flower bed. Fast forward to start of June 2023, last image in this set, already growing early potatoes, white onions and carrots!

After almost the entirety of January 2023 (not much spare time when you have a 1 year old) and a lot of swearing, I'd moved ~3,000L of soil, a 50/50 mix of clay & mixed compost, into the raised vegetable beds. My Wife, Natasha, had come up with a solution as to what to put in the now empty gap along the fence line, Red Robin Photinia Shrubs. From ground level to the top of our fence was around 2m but we found 4 Red Robins at a local nursery at 1.8m for £50 each. Before putting them in the ground, we sealed up (not air tight) the gap between the end of the deck and the ground with some leftover wood planks from the retaining wall build. This was purely to deter rodents from living under the deck. We then planted the Red Robin's with some shrub compost to give them an initial boost in their new home! After just a few months they've already gained 20-30cm in height and spread their width a lot too, they look beautiful and I wish we'd just done it from the start!

Finally just for a nice effect, I ordered some solar powered strip lighting to go around the top of the retaining wall. It came with a weatherproof solar panel that you can stake into the ground and 10m of adhesive strip lighting but we had excess so cut it to size. See picture of the finished article!

Step 7: Enjoy the New Garden

With 2023 being the first year with not much to do in the Garden, we are finally able to just enjoy and relax! The Grass seed we bought still hasn't fully established after two months, but we purposely bought a lazy slow grow mix to make the area less maintenance. As the years go on and everything grows more and more, we can't wait to see how the area evolves!

Step 8: Latest Update - June 25th 2023

Thought I'd just upload a picture of what the Garden now looks like a month after I initially finished writing this Instructable, the grass is now very close to being fully established and the flowers are out!