GrowingHQ

Growing methods

Where you grow changes what will grow. Every plant in the catalogue is assessed per method, and each method here says how much of that assessment actually exists.

Container size and the root space it actually providesThree containers drawn to the same scale with their root systems shown inside. A 3 litre pot, about 20 centimetres across, suits herbs, salad leaves and spring onions. A 10 litre pot suits chard, dwarf beans or a single pepper plant. A 30 litre pot suits a blueberry, a crop of potatoes or a small fruit tree. Beneath, a note explains that the commonest container failure is a pot two sizes too small, because the constraint is underground and therefore invisible until the plant stops growing or dries out within a day of watering.3 litres

Herbs, salad leaves, spring onions

10 litres

Chard, dwarf beans, a single pepper

30 litres

Blueberry, potatoes, a small fruit tree

A container that dries out within a day of watering is usually too small rather than under-watered. The constraint is invisible, which is why it is so often missed.

Outdoors

Where the weather decides, and the soil is what it is.

Open groundGrowing directly in the soil where it lies, with no built structure around it. The default for allotments and vegetable plots.Assessed across the catalogue179 plants suitedTraditional dug bedA cultivated bed at ground level, worked and improved each season, usually laid out in rows with paths between.Assessed across the catalogue162 plants suitedRaised bedA contained bed of soil or compost above the surrounding ground level, typically 15–45 cm deep and narrow enough to reach across.Assessed across the catalogue166 plants suitedContainerPots, troughs, tubs and grow bags outdoors. Rooting volume is fixed and small, which changes almost everything about watering and feeding.Assessed across the catalogue177 plants suitedVertical growingStacked or wall-mounted planting, indoors or out, used where floor area is the scarce resource rather than light or soil.Partly assessed29 plants suited

Under cover

Structures that buy warmth and shelter, and bring their own humidity and ventilation problems.

Cold frameA low, unheated glazed box over a bed or over pots. Used to start plants earlier, to harden them off, and to carry hardy salads through winter.Partly assessed13 plants suitedGreenhouseA glazed structure a person can work in, heated or unheated, used to extend the season at both ends and to grow crops that will not ripen outdoors.Assessed across the catalogue86 plants suitedPolytunnelA hooped frame covered in polythene. Cheaper per square metre than glass and covering more ground, at the cost of less light and a cover that needs replacing.Assessed across the catalogue72 plants suited

Indoors and controlled environment

Where the grower supplies the light, and often the nutrients too.

WindowsillA pot on an indoor sill. The most common indoor growing situation, and the one most often misjudged.Assessed across the catalogue55 plants suitedIndoor potA pot indoors away from a window, generally needing supplementary light to grow anything productive.Partly assessed38 plants suitedGrow tentAn enclosed, reflective indoor space with controlled lighting, ventilation and often humidity. Everything the plant receives is supplied by the grower.Partly assessed3 plants suitedHydroponicsGrowing in a nutrient solution with no soil, whether in flowing film, deep water or an inert medium. Covers several distinct techniques that share one constraint: the grower supplies every nutrient.Partly assessed61 plants suitedAquaponicsHydroponics coupled to a fish system, where the fish waste is nitrified into plant nutrition and the plants clean the water.Modelled, not yet assessed13 plants suitedAeroponicsRoots suspended in air and misted with nutrient solution. The highest-maintenance soilless method and the least forgiving of interruption.Modelled, not yet assessed0 plants suited