Modern Ring Culture with Growbags

At one time ring culture was a popular greenhouse growing method for tomatoes, cucumbers, peppers and melons. The idea was that water was supplied to the plants through a trench filled with aggregate and the plants were fed via the compost held in bottomless pots placed onto the aggregate.

At the end of the season the plants and the small amount of compost would be recycled into the garden and the aggregate removed and cleaned. This was less work than digging out and replacing border soil each year but still fairly time consuming.

Modern Ring Culture

Nowadays we're more pressed for time than ever before so anything that saves time is welcome. The grow-bag seemed an ideal solution but as competitive pressure forced down the price, the size and quality of the compost inside the grow-bag has generally declined.

There are various solutions to the problems but one technique enjoying a resurgence is ring culture utilising the grow-bag. To this end you can buy special double pots that are fitted into the grow-bag.

The plants go into the inner pot which is filled with a good quality compost. The plants are fed as normal with a liquid feed, either a proprietary tomato fertiliser or a home-made liquid fertiliser such as comfrey tea.

Watering takes place through the outer pot that surrounds the compost filled centre. The grow-bag itself merely serves as a water store once its nutrients are exhausted. This method is really a sort of hybrid between conventional growing and hydroponics.

Recycle the Grow Bags

At the end of the season the grow-bags can be used as a soil conditioner. Removing the grow-bags will mean that any pests or diseases are not left in the greenhouse to build up pests and disease problems for future seasons.

The method can be accomplished by using ordinary plastic plant pots, an old eight inch pot(20 cm) is ideal, just cut away the base and cut into the growing bag's top. The plant will be fed through this pot.

In-between the plants, insert 7.5 cm pots into the grow-bag. Water is introduced via these pots and held in the grow-bag just as water is introduced via the outer pot with the special double pots.

At the end of the year the grow-bags are used in the garden just as described above.

This modern variant on the old ring-culture method is easy to set up and cheap. It's also a good way to give a greenhouse border a rest for a year and starve any pests out.