DIY hydroponic gardens

How to grow plants without using soil

Some would say digging around in the dirt is all part of the fun when it comes to gardening but soil isn’t essential for growing plants. In fact, hydroponics (the technical name for soil-free gardening) has been around for thousands of years – and is as relevant and useful today as ever. Here’s the lowdown on how it works and why you should think about going soil free.

What is hydroponics?

Hydroponics is a method of growing plants using a mineral nutrient solution in water and an inert medium such as pertile or gravel, instead of soil.

Why go soil free?

Hydroponics is cheap, eco-friendly and a sustainable way to grow plants and crops, so saying so long to soil could help save your pennies and the planet (not to mention that manicure, of course). It’s also ideal for green-fingered city dwellers that don’t have the space for soil beds.

A practical advantage of hydroponics is that the strength and pH of the nutrient solution can be controlled so the plant receives just the right amount of food.

How to build your own hydroponic garden

You can build your own hydroponic garden using recycled materials or by buying a specially designed kit.

For urbanites with a lack of outdoor space, this DIY version by designer Antonio Scarponi makes clever use of Ikea products.

Or for a simple low-cost alternative using polystyrene containers, why not try this version adapted from an original idea by Arizona University professor and director of the Controlled Environment agriculture center Dr Gene Giacomelli.

What you’ll need:

  • Heavy-duty bin liner
  • Polystyrene cool box with deep lid
  • 6 polystyrene cups
  • 6 gallons distilled water
  • Marker pen
  • Craft knife
  • Perlite
  • Sphagnum moss
  • Plant(s) of choice  
  • Plant nutrient mix

What to do:

  1. Line cool box with bin liner and fill with filtered water.
  2. Using the top of a cup as a template, trace six evenly spaced circles on the box lid. With a craft knife, cut out circles 1/4 inch smaller than the cup lid circles.
  3. Using the craft knife, cut a small hole in the bottom of the cups. Place Sphagnum moss in the cups and top with perlite, filling to just under the rim of the cups.
  4. Insert plant into the perlite, and fill in with more perlite around it.
  5. Place the lid upside-down on the box. Place the cups in the holes of the lid.
  6. Water the plant each day with nutrient mix, making sure that the water level in the container is not too high: There should be about an inch of room between the water line and the bottom of the cups.
  7. After a week to 10 days, roots from the plant should begin entering the container. As the plants grow, pick leaves as desired.