GrowingHQ

Vegetables for a shallow container

A window box, a trough on a wall or a grow bag on a balcony gives about twenty centimetres of soil, and that single number decides more than anything else about the plant. Leaves, salads and the shallow-rooted alliums are completely unbothered by it; anything grown for a long root or a big fruiting frame is not, and no amount of feeding compensates. This is the list that separates them, and it is deliberately narrower than the general container question — which returned nine vegetables in ten and told nobody anything.

How this list was built

Generated from the catalogue by the same engine that powers What can I grow? — 14 of the 47 vegetables qualify. It is published because it names a question people ask, returns enough plants to be useful, does not return most of the group it is about, and rests on fields that are actually populated. Lists that fail any of those are on the coverage page instead.

14 plants
PlantTypeLightSpacingMin. pot depthIn a container
BeetrootBeta vulgarisVegetableStraightforwardFull sun, Partial shade10 cm20–25 cmwell suited
Chilli pepperCapsicum annuumVegetableSome care neededFull sun40–45 cm20 cmwell suited
Lamb's lettuceValerianella locustaVegetableStraightforwardFull sun, Partial shade10–15 cm12 cmwell suited
Land cressBarbarea vernaVegetableStraightforwardPartial shade, Dappled shade, Full sun15–20 cm15 cmwell suited
LettuceLactuca sativaVegetableStraightforwardFull sun, Partial shade15–30 cm15 cmwell suited
Pak choiBrassica rapaVegetableStraightforwardFull sun, Partial shade20–25 cm20 cmwell suited
RadishRaphanus sativusVegetableStraightforwardFull sun, Partial shade2.5–5 cm15 cmwell suited
RocketEruca vesicariaVegetableStraightforwardFull sun, Partial shade10–15 cm15 cmwell suited
ShallotAllium cepa var. aggregatumVegetableStraightforwardFull sun15–20 cm20 cmwell suited
SpinachSpinacia oleraceaVegetableSome care neededFull sun, Partial shade15 cm20 cmwell suited
Spring onionAllium cepaVegetableStraightforwardFull sun, Partial shade2–5 cm15 cmwell suited
EndiveCichorium endiviaVegetableSome care neededFull sun, Partial shade25–30 cm20 cmworkable
GarlicAllium sativumVegetableStraightforwardFull sun15 cm20 cmworkable
OnionAllium cepaVegetableStraightforwardFull sun10 cm20 cmmarginal

This is one cut through the vegetables, which compares every one of them on foliage, size and container suitability — including the ones this list rules out, and why.