MAKING LOW-COST LARGE WICKING BEDS
Initially we made the sides of the wicking beds out of chicken wire and straw to save cost as we were still proving the concept. After five years rust became a problem and we had to rebuild the beds. We now use premium fencing cloth and 750 mm pegs
The long bed shown below is an old design, we now use shorter ones. These give more flexibility to adjust watering and plant nutrition to a particular crop.
Click here to see 'Our current lay-out'
· hardwood pegs, pointed, 750mm long,
· fencing or scaffolding cloth, premium, 1.8m wide,
· builders plastic, 200um,
· 90mm PVC storm-drain pipe,
· a 90 degree PVC bend,
· duct-tape to close one end,
· clouts for nailing the cloth to the top of the pegs.
· a shovel and a rake to level the soil,
· a spirit level,
· a measuring tape,
· a heavy hammer to drive the pegs in,
· chalk for marking cloth and plastic,
· a pair of heavy duty scissors,
· a lighter hammer to nail the clouts,
· an industrial staple to staple the cloth to the
outside of the pegs.
· a drill with 40mm and 100mm hole-cutting
BUILDING SEQUENCE IN DETAIL
1. Cut a plastic liner at least 800 mm wider and longer than
the length and width of the bed.
2. Fold 800mm in length-wise at both sides and at the ends
to make it easier to place.
3. Place it in the bed ensuring that the sides can be
extended upwards evenly.
1. Cut a length of 90 mm PVC storm-drain pipe about 30 mm shorter than the length of the bed.
2. Cut large (100mm) holes at regular intervals of 30 - 50cm to make sure the water spreads. These holes are to be placed face-down, facing towards the bottom.
3. Cover one end with duct-tape.
The fill pipe
1. Cut a 600 mm length of 90 mm PVC pipe, longer if desired
2. Attach this to the open end of the pipe with a 90 degree PVC bend. This allows easy inspection of water levels.
3. Place the combined PVC pipe and fill pipe on the liner.
1. Start filling the bed with your soil mix working from the middle towards the sides while gently pushing the plastic up along the sides as you go. Take special care in the corners that all the plastic is folded up and none is horizontal and forming small channels through which water drains out. We learned that the hard way.
2. Only half fill the beds.
3. Push the plastic liner down over a length of about 30 cm to the desired level. Pick a position furthest away from the fill pipe and on the side from which the bed will be worked.
4. If you use an in-bed worm/composter place it in the centre of the bed at the right depth.
5. Then fill the bed to the top with your soil mix.
The first crop
1. Spread an organic mineral supplement and the pre-planting fertiliser or compost over the surface and work it in.
2. Fill the reservoir with water.
3. Soak the bed from the top till water starts draining through the overflow. (Only soak the bed when new or when it has dried out completely.)
4. Plant the crop.
1. Cover the surface with good mulch or grass clippings.
This will become food for worms and for the micro-flora in the soil.
1. We now prefer the plastic to go to about 5-10 cm from the surface to reduce evaporation through the sides. It also keeps tree roots out.
We had tree roots come up between the beds, grow through the cloth, over the top of the liner and into beds. The crops started to fail. Tree roots easily travel twice or more the height of a tree.
We dug a trench around the shade-house and check that once a year. It is less work than redoing all the beds.
2. We use a mixture of 40% clay, 50% sand and 10% wormcast or other organic matter.
1. Mark-out the bed; we suggest making it 0.85 m wide or
less for shorter arms. This allows 1.8 m wide fencing cloth
to cover the width and the two sides of the bed, and have
5-10 cm on either side to fold over the pegs.
2. Level the bed!! This is critical. Beds can be staggered
down a slope, but each individual bed must be level both
ways to prevent water-logging at a low side.
3. Hammer in 750 mm long stakes evenly spaced at 50 - 60
cm apart, leaving them 40cm above ground.
Use longer stakes in soft soil.
4. Cut a length of fencing cloth equal to the length of the bed
plus twice its height plus 20 cm to fold over the pegs.
5. Place it on the inside of the bed, spread it along the
bottom between the pegs, up the sides and over the
pegs. It is better to have it a bit tight than too loose to
avoid excessive bulging.
6. Nail the cloth to the top of the pegs while stretching it
tightly length-wise along the top. Fold the extra cloth in
the corners in and, if possible, nail that extra to the top
of the middle pegs of the short sides to reduce bulging.
7. Staple the cloth to the outside of the pegs for a tidy
EASY GROW VEGETABLES . NET