raised soil means better drainage and increased temperatures
Garden beds operate best when they’re raised. 200mm high is ideal (400mm is fine but you just need more soil which can be expensive and you’ll probably need to water more often).
But even if you can get them up to 100mm that will work well. Rob’s beds are only 100mm high. The reason is that the soil is warmer when raised, and it doesn’t get compacted and water-logged in the winter.
If you’re raising a bed, you need to contain it somehow. It doesn’t matter what with, except if you use tanalised timber (treated timber) you’ll need to line the timber with polythene to stop the chemicals from leaching into your soil. You can use any old bits of wood or corrugated iron or rubber you might have lying around, or you can buy kitset beds for reasonable prices if you don’t have a set of tools at the ready.
It’s good to make beds out of something continuous, so the slugs and snails can’t get in so easily.
If you’re creating a few raised garden beds, you’ll naturally create pathways in between each. 600mm is a good width for paths. You can get a wheelbarrow up a 600mm width. Many people just lay sawdust or straw on their pathways, but if you’re laying gravel or shells, it’s quite good to put weed matting down first. Lay your weed matting down as a big sheet and put your raised bed on top of it, then, leaving a 100-200mm strip on the inside of the bed, cut away the rest of the weed matting, so you access the soil again. Gravel and shell pathways heat up nicely and help to keep the soil of garden beds warm.
Macrocarpa is our raised-garden-bed wood of choice, because it’s local and forested sustainably. It’ll last about 10 years before rotting down, but then you just make new ones. Planks are best about 40-50mm thick. And you wouldn’t want to make your beds more than about 1200mm wide because you’ve got to be able to reach into the bed. Remember to bang in pegs in each corner so the bed stays square and doesn’t move.
Before adding soil, you need to think about irrigation. Veges need constant watering in the summer and you don’t want it to be a hassle. If you’re thinking of installing a sprinkler system, now’s the time to do it running it back to your hose, especially if you want to put a timer on it. Other options include a drip system or a soaker hose, both of which work well because they get to the roots of plants, which sometimes sprinklers don’t. And then there’s the good old watering can. I was once told you water in the morning for growth and in the evening for recovery (if plants have become a bit dry).
Garden beds need to get around 6 hours of sun a day (when it’s sunny!) for optimal growth. But summer veges like lettuces and rocket actually like a bit of shade at the beginning or end of the day.
It’s important not to worry about how big a garden to make. Just get started. If you live in an apartment, get yourself some containers for the balcony. If you’ve got a bit of land, make one or two beds about 1200x200x2700mm (that’s the size in our video) and see how you go with that. Start with what you think you have time for. Aim for success!
Production: Ollie Logan, Vince McMillan and James Watson