Tomato

Cordon or bush: the choice that shapes the whole summer

Before the variety, before the colour of the fruit, one question decides everything: is the plant indeterminate or determinate? An indeterminate keeps growing from a terminal bud — it climbs, it produces over a long season, and it needs serious support plus the regular removal of side-shoots, those growths that appear in the angle above each leaf. A determinate stops itself at a set size, fruits in a more concentrated flush, and is not side-shooted at all.

Behaviour, mechanism and limits

The tomato is generous but legible: nearly all of its troubles trace back to the same cause, irregularity. Split fruit follows heavy rain or watering after a dry spell — the flesh swells faster than the skin can stretch, and it tears. Blossom end rot has the same root. So, often, does flower drop. A mulchA layer of material (bark, straw…) laid on soil to retain moisture and limit weeds. and steady watering solve more problems than any product.

One planting detail is worth knowing: tomatoes are planted deeply, with part of the stem buried. Unlike most vegetables, they produce adventitious roots all along that buried stem — a bigger root system, therefore better access to water, which serves the consistency you are after.

The limits are real. No hardiness at all: the crop ends with the first cold. And in Britain late blight (Phytophthora infestans) is the dominant outdoor threat in humid weather. It marks the leaves with yellow then brown patches before reaching stems and fruit, and once it is on a plant there is no garden cure — everything is decided beforehand, by air movement, watering at the base and rotation. It is precisely why so many British gardeners move tomatoes under glass.

Two observations that contradict the literature

Our plot lies within the Bellet appellation area, on the Nice terraces above the left bank of the Var. This terroir has a documented peculiarity: the Var valley channels the movement of air, and that windiness is credited with limiting humidity and fungal disease. We experience it daily as a near-constant light wind.

First consequence, and it runs counter to everything above: we only get blight under glass. Never outdoors. That is the reverse of the usual framing, which makes blight the outdoor grower’s problem in humid weather — a framing that comes largely from wetter climates, Britain among them. The mechanism is simple enough: outside, wind dries the foliage and shortens the leaf-wetness period; under cover, the air is still. Here it is the protection that creates the risk, and ventilating the greenhouse becomes the first plant-health task of the week.

Second consequence: our real pest is not a disease but the brown marmorated stink bug (Halyomorpha halys), recognisable by its mottled brown shield-shaped body and the white bands on its antennae. Its puncture injects digestive enzymes that necrotise the flesh around the point of impact: a punctured fruit is lost.

Our practice, with no embellishment: watching and hand-picking, insect netting — the fine-mesh physical barrier remains the most satisfactory documented protection — and, when we are overwhelmed, early harvest. There is no simple answer, and claiming otherwise would be a lie. For British readers the point is different but worth keeping: the insect is not yet established in your country, and recording a sighting is currently more useful than treating one.

We grow mainly large slicing tomatoes and heritage varieties, saving our own seed wherever we can, on black plastic mulch with drip irrigation on a timer. That mechanised consistency is not a luxury: it is what keeps blossom end rot and splitting at bay.