Recycling Green Waste into Garden Compost

Why Coastal Soil Needs Every Bit of Compost You Can Make

If you garden within a mile or two of the sea, you already know the problem. That lovely light soil drains beautifully in February and turns to dust by July. Nutrients wash straight through it, salt spray scorches tender leaves, and the wind strips moisture from the surface faster than any hosepipe can replace it. Sandy coastal ground is generous with drainage and mean with everything else.

The answer is organic matter, and lots of it. Compost does two jobs at once on sandy beds: it holds water in the root zone and it holds on to nutrients that would otherwise leach away with the next downpour. Buy it by the bag and you will spend a fortune. Make it yourself from the green waste your garden already produces and you will have a free, steady supply of crumbly, dark, sweet-smelling compost that your coastal beds will adore.

Here is how to do it properly, from the first soft cutting to the last forkful.

What Goes In: Soft Cuttings, Cardboard and Kitchen Scraps

The secret to good compost is balance. You need roughly equal volumes of soft, sappy "green" material and dry, woody "brown" material. Get that ratio right and the bin will heat up, break down quickly and never smell.

From the garden, collect:

• Soft cuttings — grass clippings, spent annuals, annual weed tops, vegetable trimmings, hedge clippings that are still green and pliable.
• Old bedding plants and the leafy tops of perennials cut back in autumn.
• Seaweed in small quantities if you garden right on the coast — rinse it first to wash off excess salt, and never take it from a protected shore.

From the kitchen, add fruit and vegetable peelings, tea leaves, coffee grounds, eggshells crushed up, and the paper bags they arrived in. Avoid cooked food, meat, fish and dairy, which attract rats and foxes — a particular nuisance in seaside towns where bin day is a weekly battle.

For browns, keep a stash of cardboard next to the bin. Torn-up delivery boxes, egg cartons, toilet roll tubes — all excellent. Avoid glossy printed card, and never compost perennial weed roots such as couch grass or bindweed. On the coast those spread like wildfire, and a compost bin is a perfect nursery for them.

Siting and Building a Covered Bin

A covered bin is essential in a coastal garden. Without a lid, driving rain and salt-laden spray soak the contents, the heap turns sour and anaerobic, and you end up with a slimy mess rather than crumbly compost.

Choose a spot that is sheltered from the prevailing wind — behind a hedge, a shed or a windbreak — but still gets some sun. A wooden bin made from four pallets wired together, with a lid of old corrugated sheet or marine ply weighted down with a brick, works superbly and costs very little. A lidded plastic bin is fine too, though the wooden version is easier to turn and gives you better access with a fork.

Site it on bare soil if you can, not on concrete. Worms and beneficial fungi will migrate up from the ground and speed everything along. If you must stand it on paving, put a layer of rough twigs or broken branches in the base first.

Layering, Turning and Keeping It Sweet

Build the heap in layers roughly 15cm deep: a layer of soft green cuttings, a layer of torn cardboard, a scattering of kitchen scraps, then repeat. Water each brown layer lightly as you go — the whole heap should feel like a wrung-out sponge, not dripping and not bone dry.

Turning is where most people give up, and it is exactly where the magic happens. Fork the contents from one side into an empty space or second bin every fortnight or so during the growing season. This reintroduces air, mixes the greens and browns, and gets the heap cooking again.

If it is working, the middle will be noticeably warm and you may spot a thread of white fungal growth. If it smells sour, add more cardboard and turn it. If it is dry and doing nothing, water it and add grass clippings. If fruit flies gather, bury the kitchen scraps deeper in the middle.

Using Crumbly Compost on Sandy Beds

Your compost is ready when it is dark, crumbly, smells earthy and you can no longer recognise what went in. In a mild coastal climate with a warm summer, that can take as little as three months; in a cold, windswept spot, allow six.

Use it in three ways:

• As a mulch — spread a 5cm layer over the soil surface in spring. It feeds the soil slowly and, crucially, shields sandy ground from drying winds and rain splash.
• Dug in — fork it into the top 20cm before planting. This is the fastest way to improve water retention on hungry sand.
• As a planting pocket — mix a couple of handfuls into the hole when putting in lavender, sea thrift, eryngium or other coastal favourites. They will establish far faster.

Keep feeding the bin all year round. Every barrowful you spread is a barrowful of water and nutrients that stays in your soil instead of draining away to the sea.