I don’t like to dwell too much on the economics of growing vegetables in containers mostly because I do it as a hobby and not a way to save money. The second reason is that it is incredibly difficult to quantify the costs going in or coming out of this sort of project. However, I thought I might share a few thoughts on the subject in case people are interested.
I realise that many people cannot afford to live in a house with a nice garden and often live in apartments with little or no private outdoor space. I am aware how difficult it is to find private outdoor space in London apartments because we spent two months looking before we found the apartment we are now renting. I had been really stubborn about it and by the time we found this lovely flat I was really ready to compromise and take something I did not like which had a very small balcony. Thank goodness we did not give in to the estate agents who told us a balcony was a pipe dream on our budget!
So, how much does it cost to grow your own food in containers? I will attempt a very approximate calculation just to give a feel. As with any project; the larger the scale of your operation the more efficient the costs per unit. Here is my calculation:
Pots: Including postage £1.40 each (£13.95 total)
I recently bought 10 second hand pots online for this year’s crops. I thought it was a great buy because all the pots are the same size and shape so they stack together neatly for storage or moving. They are also square shaped in plan so they are space efficient on the terrace, which is very important!
Soil: £1 each
These pots can hold 11litres of soil. Assuming I do not fill them to the brim they will probably need closer to 10l each. I have to buy my own compost for the terrace and a 70l bag costs from £5 to £8 depending on quality.
Seeds: £0.80 each
Next up is seeds. Most people will not grow one variety of vegetable exclusively. If you have less space you are likely to try out many things with only one or two of each plant. A packet of seeds is approximately £1.60 so if you grow two of each you can spend 80p per plant. Of course you can also save your own seeds or try seed swaps, but initially I think most beginners will start by buying some seeds.
Miscellaneous covers all the extra things you may need to buy. Last year we purchased tomato food, a spray bottle for spraying milk on powdery mildew, canes and twine, vermiculite, secateurs and magazines. There is always something miscellaneous to buy, every year. From seed starting trays to watering cans, labels to insect repellents, fleece to cloches I suspect that even very experienced gardeners still need to buy something every year. Depending on the size of your space the cost per container can vary a lot so I have given 50p as an estimate. The smaller the space the more you can get away with (use scissors instead of secateurs, water from a glass instead of a watering can etc.)
Total: £3.70 per pot (for the first year).
The cost should go down over the years as you should not need to buy more containers unless you are expanding the operation as we are this year. Seeds can keep for a few years and you can learn to save your own over time too.
Now, the million dollar question? How much can you reap from one pot over one year? This depends on luck, conditions and the specific vegetable types and varieties you plant. I would guess that last year we got 12-18kgs of tomatoes from four pots but we only got 3 or 4 courgettes before they got powdery mildew and died. The tomatoes were followed by swiss chard which is now ripe and we might harvest enough chard for 10-20 meals if we are lucky. The courgettes, on the other hand, were followed by carrots which are still alive but are quite small so I would be surprised to get more than 1-2 kgs from the two containers. So the tomato containers (with swiss chard) have given us 2-4.5kgs of tomatoes plus 2.5-5 side dishes of chard per container. Whereas the courgette containers have given 1-2 courgettes and at most one kilo of carrots each in the same time frame. The lesson is, choose your containers crops wisely. Think about disease resistance, cost at the supermarket and yield per plant.
I hope this has been of some help to anybody considering growing their own. Don’t forget that it is worth it for the enjoyment of growing and the freshness of your home grown food. Naysayers might tell you that the cost of your labour alone would make even the most thrifty vegetable growing scheme a loss maker!