Frequently Asked Questions

Is 30% shade enough?

YES. While it may not feel much to us, plants feel the effect much more than we do. People from Darwin, Townsville, Northern NSW and places further south have confirmed that 50% shade is too heavy. They replaced heavier shade with 30%, as we had to do. Our plants grew elongated and weak because they did not get enough light.

And please note: building a shade-house under overhanging trees also can reduce light too much.

What to grow in shade-houses?

Within our shade-houses we have grown intensive small crops, as these give the best returns per square meter: lettuce, various spinaches and Chinese vegetables, cucumbers, peas, beans, carrots, parsley, shallots, leeks, garlic, etc. And also crops that need on-going protection against insects: tomatoes, sweet corn, capsicum, broccoli, cabbage and cauliflower.

Larger crops such as sweet potatoes, pumpkins, water melons etc that spread and need space are better grown outside the shade-house.

Why use wicking-beds in the open air?

This summer (2009 -10) we tried to use raised beds but without the plastic liner and water storage for those larger crops. We had no rain from May to late December and temperatures got to 40 C. Once the weather warmed up, it became next to impossible to keep the water up. The crops wilted severely, even while a drip system was going. But the crops in a wicking-bed next to them, also out in the open, never looked stressed. So from now on we will only use wicking-beds even outside the shade-houses. They will have pleny of water storage and space around them to spread their vines.

How important is drainage?

VERY. Early on, some friends used large tubs with small drain holes. These holes quickly clogged up, partly due to worm activity. During heavy rain the tubs filled to the top with water and became soggy, water-logged swamps. The soil had to be dug out, large drains installed and new soil put in.

Wicking-beds with unlimited drainage or large diameter drains do not suffer this fate. Beds made from fencing cloth with plastic folded down have unlimited drainage. Metal or wooden beds with several 25mm diameter pipes would have good enough drainage. The bed in photos 3, 8 and 9 on page WICKING BEDS performed well. After nearly eight months without rain we had 884 mm of rain during three months of warm steamy weather. The wicking-beds in the shade-houses also remained well-drained even though the paths between the beds were often ankle-deep in water. The soil retained its structure and the plants coped well. (The paths became over-grown with weeds, which was not pleasant to work in. So they are now covered with strips of old carpet to stop that.)

Is plant nutrition needed?

Yes. Wicking-beds can produce large amounts of plant material year-round. To get the best and the most from them, good plant nutrition is very important. Traditional growers can follow traditional fertiliser recommendations. However, residual salts can build up rapidly and regular flushing of the beds may be needed.

Some of our organically inclined friends are good at composting and feed their crops largely with that, but even that may not be enough. Fortunately organic growers can now also buy good organic plant food: blood and bone manure, various animal manures, and organic minerals can be used before planting. Liquid organic fertilizer, seaweed-based or carp-based, can be spread on the surface when transplanting and while the plants are small. Once the plants are established, they can be mixed in with the water when filling the beds.

Can insects get in?

Yes, small ones still can get in. Aphids, white fly and small green grass-hoppers have made serious nuisances of themselves. Occasionally we find larger ones, following us in through the door. Others can lay their eggs through the shade cloth, if the leaves touch that. So some control is necessary.

How can they be controlled?

We use only organically approved sprays and have been getting good success with a mixed spray of Neem and Pyrethrum oils. For caterpillars we have used sprays containing spinosad, based on naturally occurring soil bacteria. We let marigolds, the small yellow and orange ones, grow and seed amongst our crops to suppress nematodes.

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