If you haven't made huge quantities of compost, and you’re thinking of buying in compost or topsoil, consider instead a straw-bale garden. This is also a good way to start off new raised bed gardens.
Straw bale gardens can be built inside raised bed frames- especially useful when, as here, filling the bed with soil would involve a lot of barrowing.
Straw is not cheap, but it’s cheaper than soil and much easier to cart around.
Straw bales take at least two weeks to prepare before they are ready for planting – they need to be kept thoroughly saturated, with manure or blood-and-bone added to begin the rotting process. By the end of the season they’ll have broken down into good quality compost.
1. Choose your spot: sunny is best. A straw bale garden can be on top of concrete or soil but use weed mat/carpet underneath if building on weeds or kikuyu. Bales can also be placed inside raised bed frames.
2. Place bales upright (strings on side), leaving strings in place.
3. Stake or support them with bricks- you’ll be glad of this later.
4. Water thoroughly – this can take a while. They need to be wet to the core. Make small pockets in the top and add compost/ manure/worm casts, then water that in too.
5. Liquid feed: Every day, water on some liquid feed: seaweed or comfrey tea, liquid blood-n-bone, worm tea… If you want to grow fruiting plants like tomatoes, make sure to also add something with potassium (eg wood ash).
6: Keep them moist and keep an eye on your bales. When they heat up and the insides start to break down, they are ready.
7. Plant: Plant seedlings into a hole, adding sterile compost or potting mix. To sow seeds, make a 5cm layer of potting mix on the surface. The sides of the bale can also be planted into.