I'm sure that all are aware of the benefits of growing your own potatoes, as well as the space-saving of growing them in containers. This year, as I had come across a few old car tyres, I decided to try the suggested method.

Firstly growing potatoes in containers, requires multiple soil filling as the plant grows, so a supply of enough good well prepared soil, a must. Start by stockpiling this soil, so that the plant is not receiving differing soil structures. What is the soil requirements for potatoes? A good compost, sandy soil mix that will not compact.

This year I experimented with two soil types, one, a good quality topsoil, mixed with chicken manure and mushroom mix, and one with a topsoil, compost and sand mix. The first, topped up with the same original mix and the second with a seedling mix. Watering, was probably too much, as every time I watered we received good rain, totally over supplying the water requirements. This however did no damage as the soil drained well and the plants seemed to thrive on it.

In hindsight I think the chicken manure was not the best fertilising method in the one, as the immediate requirements for nitrogen where not met and a chemical addition needed. However I would recommend an organic fertiliser be used, as the long-term release of nutrients is more beneficial than continuous applications of chemicals, that can cause burning.

What was also discovered, the first mix tended to compact more than the second mix, avoid this as the potato root that forms the tuber you eat, needs place to develop. The less compaction, the better formation of the tuber. My first mix supplied lass potatoes than the second.

A further consideration is light. If you're within the tropics, drums and deep pots work well, as sunlight reaches the lower areas of the container. However, beyond the tropics, the deep pots create trees from plants and not bushes, and the light requirements of the plant are not met, this is where using old tyres is helpful.

So how to plant potatoes in old tyres.

1. The first tyre placed on plastic, half filled with good compost, sandy soil mix.
2. The plant, or eye from a potato planted half depth in the mix.
3. When the plant shoots and grows beyond the height of the tyre fill up to the first tyre height.
4. When the plant is the height of two tyres, add a second tyre on top of the first and half fill with soil.
5. Again when the plant bush is above the level of a third tyre add more soil. (allow for growth at this stage). The plant must reach the level of three tyres before you top the second tyre to full.
6. When the plant flowers, a third tyre added and it filled with soil to the top of the tyre.
7. Now stand back and let the plant grow.

When the plant dies back completely and the bush is no longer green you can think of cropping. The top tyre removed and the potatoes in that tyre harvested. The others can stay in the soil if wished, but then the soil needs to stay dry, otherwise regrowth can begin. Obviously if there is enough storage for your crop, harvest the container, storing the soil for reuse.

What to avoid when growing potatoes in containers.

1. Heavy soils that compact. (Soil should have 25% moisture, 25% air, 45% mineral particles, and of the remaining 5%; 80% humus 10% roots and 10% micro organisms).
2. Over fertilisation, avoid elongated tree like plants, rather a good bush with lots of leaves.
3. Continue filling as the plant grows, but do not smother it, a plant needs leaves for life.
4. Lack of sunlight, photosynthesis a major need in potatoes for good production.
5. Over watering, ensure good drainage.

A tyre planted potato can easily produce two or three pockets at harvesting, so stagger planting not to have too many potatoes at one time.