Raised beds are a great way to start your first veggie garden, to expand your garden or add fertility to an existing bed. Other names for this style include ‘the layer method’ and ‘the lasagne garden’. One of the earliest advocates of the no-dig system is Esther Deans with her famous book ‘No-Dig Gardening and Leaves of Life’.
Advantages of a raised bed:
We can build and plant veggies today
It’s a fantastic way of getting a whole lot of goodies for your plants in one place
There is next-to-no weeding in the first couple of years
It’s great when you have poor soil quality or no soil.
It’s easy and there’s no digging
How to Build Your Raised Bed
Gather the materials
The more varied your materials, the better. You need a good mix of nitrogen and carbon, which can include:
Nitrogen: food scraps, animal manures (not dog or cat poo), fresh grass clippings, weeds (no seeds or rhizome roots), a filled bokashi bin, blood and bone.
Carbon: cardboard, newspaper, brown leaves, dry grass clippings, straw (lucerne is the ultimate, others will do fine).
Compost
Prep the site
If the site isn’t flat, flatten out to desired measurements. Otherwise you can put your raised bed directly onto the lawn. Completely cover the area with cardboard or newspaper. This kills off any grass or weeds on the site.
Use standard brown cardboard, not the glossy ink-covered variety. Watering every layer ensures interaction between layers and helps them all break down.
Contain the bed
Build a simple wooden frame to hold our bed. Choose untreated timber – pine will last five to 10 years before it starts breaking down, macrocarpa will last longer but is more expensive. Other options are rocks, tin, straw bales, concrete blocks or bricks. The yard at Wanaka Wastebusters can be a good source of reused materials. You can just build your bed with no walls, this works best if you’re no-digging a larger area.
Layer the carbon and nitrogen
After the cardboard comes a layer of straw about 10cm deep. This is a carbon layer.
Follow the carbon layer with a nitrogen layer. Here we are using horse manure, but any manure or other source of nitrogen is fine. We’re looking for roughly a 10cm layer here too.
Remember to water each layer before adding the next. The process we are following here is very similar to making a hot compost heap.
Keep layering
Follow on with another carbon layer. You could use any of the carbon layers listed above. Next a nitrogen layer. You can use grass clippings, but be sure not to use any clippings from a chemically managed lawn. Again remember to water each layer before adding the next. You can add a layer of compost at any time. Keep adding layers until you run out of materials or bust out of the bed.
Firm the bed
We have finally reached the top of our raised bed. If you want to plant right away, finish with a final layer of straw slightly higher than the edge of your bed. Water the final layer, then firm all the edges and corners, tucking them into the timber sides. You are now ready to plant your seedlings!
If you are prepared to wait, you can keep layering (another 20cm to 45cm) . Leave for a month till the top has dropped down and then plant seedlings into the bed.
Planting your seedlings
Make a hole in the bed, fill with a handful or two of compost. Pop in the seedling and water in. Done. You can now plant out the whole bed with seedlings. Hey presto one fantastico No-Dig Raised Bed Veggie Garden!
Next year you can sow your seeds straight into the raised bed. If you enjoy not having to weed your veggie garden, every autumn you can add a couple more layers of manure, grass, bokashi scraps, garden weeds and straw.
Wastebusters delivers the Dr Compost home-composting programme in Queenstown and Wānaka under contract to Queenstown Lakes District Council. Check the Dr Compost Facebook page to see if there are any veggie growing or composting workshops scheduled soon.
Dr Compost can also solve any composting dilemmas for Queenstown Lakes residents, and give you personalised advice to get your composting system humming. Email him your questions to: drcompost@wastebusters.co.nz
