I was asked “I’m thinking about growing tomatoes peppers and chillies using hydroponics“, no doubt it crosses the mind of others too – either as a Project (I have no argument with that!) and perhaps in part to save labour.
Back in the 70’s I ran a project to build 2,500 sq.m. of greenhouses using Nutrient Film Technique (NFT) hydroponics to grow Tomatoes, Peppers and Lettuces, and nowadays lots of those products bought from supermarkets are grown by hydroponics. But I wonder how good an idea it is for an amateur project?
I have a 10′ x 30′ (30 sq.m.) “cropping” greenhouse, so somewhat bigger than a regular garden greenhouse, and any time saving would certainly be worthwhile, and whilst I have considered hydroponics for now I am sticking with my method.
I grow my greenhouse crops direct into the greenhouse border “soil” which I change annually. I have leaky hose along each plant rows down the greenhouse, gravity fed from a water butt with a timer. So the only labour I have is to feed via a watering can which I do when I remember, generally between once a week and once a fortnight.
My greenhouse “soil” is 50:50 well rotted manure (stacked for a year) and my homemade compost … well … I say “made”! I just pile up all the garden waste, I don’t turn it or add chemical activators, and after 12 months whatever is there is what I use. It is still pretty rough, but when it comes out of the greenhouse borders a year later it is beautifully friable, and I use that for various potting and mulching tasks. The compost / manure combination is much lighter than my regular clay soil and as such I don’t find it hard work to change each year, but changing it annually is overkill and every other year, or three, would do. I change it annually as much to have a steady supply of the nice fine friable compost that the process produces. An alternative would be to use grafted plants as they are much more tolerant of soils that have disease buildup / nutrient deficiency from mono-cropping.
Plants still need attention with hydroponics of course – picking fruit, training up strings, side-shoot removal, and those jobs still need doing if you go away from a prolonged time, or work long shifts, so the only labour saving is irrigation and feeding. You might get significantly higher yields with hydroponics, but some would say that hydroponics fruits taste watery. Many supermarket tomatoes are grown by hydroponics, and folk will base their experience on those – but supermarkets’ growers choose varieties that suit the commercial process – disease resistant, thick skins so they don’t bruise in transit, and so on – whereas home growers choose on flavour and tolerate lower yields and so on – so I doubt anyone has trialled best-flavour varieties in a side-by-side test of both soil grown & hydroponics to be able to say if they can taste the difference. However, gardeners “grow Tomatoes mean” for flavour, and you can’t do that with hydroponics because the plants will have everything they want “just so”, in particular water.
If you want a project then don’t let me stop you!! but if you want minimal maintenance cropping then soil-based (rather than container or bag) saves the fairly significant start-up cost of hydroponics, and negligable risk of crop-loss due to equipment failure / power outage