The Problem: Ground clutter and saturated walls
Small paved yards quickly become obstacle courses of ceramic pots that bake dry in three hours and crack at the first hard freeze. Moving plants onto a boundary wall solves the floor-space shortage, but screwing wooden boxes straight onto brick mortar creates a permanently wet poultice. Within two seasons, algae stains the wall and the back board of the planter rots away while full of heavy wet compost.
Our vertical ladder frame separates the structural wall rails from the soil troughs. Two vertical stiles bolt to the masonry on 15mm vulcanised rubber standoffs. Individual cedar troughs hook onto angled 45-degree French cleats, cascading slightly forward so overflow irrigation drips into the trough below rather than streaking down the brickwork.
Material & Hardware Schedule
Wet soil weighs roughly 1.4 kilograms per litre. A single 750mm trough holds 18 litres of saturated compost, meaning each tier must safely carry 25kg without pulling out of weathered mortar.
| Component | Qty | Dimensions (mm) | Material Specification |
|---|---|---|---|
| Vertical Wall Stiles | 2 | 38 × 63 × 1400 | UC4 treated CLS or Western Red Cedar; drilled for M8 masonry anchors. |
| Wall Cleat Rails | 3 | 22 × 95 × 760 | Ripped lengthwise at 45° bevel to yield both wall and trough cleat halves. |
| Trough Side & Base Boards | 9 | 19 × 145 × 750 | Untreated larch or cedar (safe for edible culinary herbs). |
| Trough End Cheeks | 6 | 25 × 145 × 180 | Thicker stock to accept stainless screw threads without splitting. |
| Breathable Liner | 3 | 450 × 900 sheet | Non-woven geotextile landscape fleece fastened with monel staples. |
Assembly & Mounting Sequence
- Rip the 45-degree cleat pairs: Tilt your circular saw shoe to 45 degrees and rip each 22×95mm rail down its centreline. One half screws to the vertical wall stiles (bevel facing up and toward the wall); the matching half screws to the back of each planter box.
- Assemble the free-draining troughs: Screw the front and back boards to the 25mm end cheeks. Leave a deliberate 8mm drainage gap down the middle of the bottom boards, then line the interior with permeable geotextile fleece so soil stays in while excess water escapes immediately.
- Fix stiles into solid brick—never mortar joints: Hold the vertical stiles against the wall with a spirit level. Mark four fixing points into the middle of sound bricks (avoiding crumbling lime mortar courses). Drill 10mm holes, blow out brick dust, and fix with M8 Fischer Duopower plugs and stainless coach screws over 15mm rubber spacer washers.
- Stagger the cleat offsets: Pack the bottom cleat rail out by 20mm using timber blocks so the lowest trough sits slightly proud of the upper tiers. This gives trailing thyme and strawberries extra skylight and catches top-tier drips.
"Line edible herb troughs with permeable woven landscape fabric rather than black polythene rubble sacks. Polythene turns wet compost anaerobic; woven fleece lets roots breathe and prevents stave rot." — Fieldnote #09: Root Zone Drainage
Seasonal Care & Soil Refresh
Shallow wall troughs dry out faster in July winds than ground beds. Mix 20% horticultural grit and 15% composted bark fines into peat-free multi-purpose compost to hold moisture without waterlogging. In late November, unhook the top tier and move frost-tender rosemary or lemon verbena under the eaves or beside your garden storage locker.