by Wally Richards

NEW SEASON… GARDENING WITHOUT SOIL

There is more than one way to grow plants besides in the soil or in containers with growing medium.

The most obvious one of these is hydroponics where a solution of nutrients is pumped into channels then it is gravity feed along the channel, past the roots of plants growing there, to return to the holding tank.

This is a constant flow (CF) of nutrients which the plants take up and in doing so the solution becomes weaker and more nutrients have to be added.

The amount of nutrient is measured by a CF meter and depending on what crop is grown the CF level is increased or reduced. (The conductivity factor (CF) of dissolved salts in a given solution is a measurement of conductivity. Using the electrical conductivity between two electrodes in a water solution, the level of dissolved solids in that solution can be measured.)

The nutrient flow needs to be aerated and this is often achieved by it dropping from the channel back into the holding tank otherwise a air pump and air stone are used to keep the oxygen level up and prevent the water from becoming stagnant or dead.

The reason is that plants need oxygen around their roots to prevent them from rotting.

That is why in wet times when the drainage is poor and plants are sitting in waterlogged soils, the roots rot and the plant dies. Mulches on the soil in wet times are deadly as they prevent the soil from breathing.

In dry times mulches are great to help conserve moisture in the soil.

Another hydroponic method is called ‘Flood & Drain’ This is when you have a bed say 20cm deep filled with sand or perlite and plants are growing in the bed.

Every, say 20 minutes, the bed is flooded with nutrient and the surplus is drained back to the holding tank. A bed like this allows one to grow root crops such as carrots, onions and yams.

In both these cases a nutrient is made up from what is called A & B powders which are added to water separately and then combined when placed into the holding tank.

Because the CF level is dropping as plants take up the food, more of A & B need to be added to reach and maintain the ideal CF level for the crop grown.

Another factor occurs over time and that is the pH level which is a measurement defining the acidity or alkalinity or the nutrient.

Once again depending on what is being grown the pH should be at a level that the crop needs to be able to absorb the nutrient. A pH level too high or too low will inhibit good plant growth.

In more recent times a new method of growing was promoted called Auto Pots.

The system is very interesting and containers sit in a individual or twin pot tray that has a mechanical value device that is connected to a holding tank.

The value opens and floods the tray and then shuts off the flow into the tray till such time as the tray becomes dry. Then the value opens again allowing a fresh lot of nutrient to flood the tray.

All the nutrient is used and there is no return to the holding tank so you are not adjusting CF or pH.

The container sitting in the tray has Coco Choir fibre or similar and your seedling is planted into that. Nutrient rises and plants roots go down and the plant grows. It is best suited for tomatoes, capsicum, chili, cucumber and eggplants (aubergines). All of which are heavy feeders.

We used to sell the containers and systems when they first appeared in NZ and a few keen gardeners purchased and enjoyed the easy and different way of obtaining great results.

Along with the grow pots we sold a liquid hydroponics solution originally called Matrix, named as such because until added to water for diluting the Matrix held the A & B aspects apart. Later when we re labelled the nutrient we called it Wallys Plant Food.

It is a very powerful nutrient that with auto pots you can grow capsicums as good as the hydroponically grown ones you see in the supermarket.

Wallys Plant Food is not cheap with a litre selling retail for $30.00.

What makes matters worse with the Grow Pot growing, is things can sometimes go wrong with a value not shutting down (sometimes a slug has got into the value area) and if the tray becomes too full, nutrient will flow out of where the tube comes into the value and then a siphoning action takes place and you lose a lot of expensive food.

So having auto pots in both my glasshouses I have decided that I will use the system this season to water the plants that I am growing which will be sitting in the auto pot trays with non chlorinated water to look after their watering requirements.

If any thing goes wrong I will only loose water till I fix it.

So it’s an excellent automatic watering system.

Now for food I intend to put Wallys Secret Tomato Food with Neem Powder in the tray which the pots sit in and also when I fill the containers with coco choir, halfway up I will place other goodies such as The Secret Tomato food with Neem, a little Ocean Solids, a bit of Unlocking Your soil and BioPhos; then fill the pot up with the coco choir and plant a tomato seedling, cucumber or what ever into each pot.

I can then add a little Magic Botanic Liquid (MBL) to the holding tanks for some extra minerals and elements.

I will make up some molasses and MBL into one litre Trigger sprayers and have that handy so when I am checking the system, I can give the foliage a spray.

That will help the plants grow better, healthier and faster even if there is not much direct sunlight.

This system is ideal in glasshouses but there is no reason that you cant use auto pots in the same way outside in a sunny sheltered area, on a porch etc.

For the holding tank of water use a 20 litre jerry can that you can screw a three quarter inch (about 19 mm) threaded irrigation off take into. A short length of 13-mm irrigation pipe with an end stop and the off take connector to the value with the smaller feeder tube.

Just fill the 20-litre can when it gets low and that takes care of your watering.

My article, Future Proof‘ was sent out by e-mail yesterday to all those that requested it (several hundred) I know it took me about 2 hours to send each one individually. There were a couple of hiccups while doing it as the computer had problems keeping up so if you asked and never received, please email me and I will send, but I think I got everyone covered. It ended up 78 pages, so a long read, hopefully it will give readers some ideas you can use in case of disasters, natural or man-made.

Any one wanting a copy, which I send as a pdf file, just e-mail me wallyjr@gardenews.co.nz put in the subject line, Future Proof.

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