Should I remove the leaves from my tomato plants?

Two beliefs drive most tomato defoliation and only one of them is right. Removing lower leaves genuinely improves airflow and reduces disease. Removing leaves to "let the sun get at the fruit" is based on a misunderstanding of how a tomato ripens, and taken far enough it costs you the crop, because the leaves are what make the sugar the fruit fills with.

Step by step

1. Start from the bottom, not the top.The leaves nearest the soil are the ones that catch splash-borne spores, stay wet longest and contribute least. Those are the ones worth taking.
2. Remove leaves below the lowest truss you are actively picking.Once a truss is ripening, the leaves below it are past their useful life. Taking them opens the base of the plant to air and light and makes watering at the base easier.
3. Take any leaf that touches the soil or the compost surface.Blight, botrytis and leaf spot all arrive from the ground upwards in rain splash. Breaking that first contact is the cheapest disease control there is.
4. Remove diseased and yellowing leaves whenever you see them.A yellowing lower leaf on a fruiting plant is normal senescence — the plant is withdrawing nitrogen for the fruit. Remove it. A leaf with brown blotches or grey fuzz goes in the bin, not the compost heap.
5. Stop at the leaves above the ripening truss.Those leaves are feeding the fruit that is swelling now. Leave them. A useful working rule is to keep at least three or four healthy leaves above the highest truss you want to fill.
6. Thin rather than strip if a greenhouse is congested.Where plants are close together, take individual leaves that overlap a neighbour rather than clearing whole sections. You want air moving between plants, not a bare stem.
7. Do it on a dry morning, a few leaves at a time.Snap the leaf downwards and outwards close to the stem so it comes away cleanly. Removing a lot at once is a real shock to a fruiting plant — spread it over a week or two.
8. Late in the season, prioritise airflow over foliage.From about September in most of the UK, cool damp nights make botrytis the bigger risk than losing photosynthesis. That is the point to be more aggressive with lower and inner leaves.

Tips

• If a leaf is shading a truss you are impatient about, bend it aside and tuck it behind a string rather than removing it — the fruit gets light and the plant keeps the leaf.
• Do not remove leaves and take the growing tip out on the same day. Both are checks to the plant and together they can stall it for a week.
• Bin or burn diseased tomato foliage. Blight-infected material on a compost heap is how the same problem arrives earlier next year.
• Outdoor plants under a rain shelter benefit more from lower-leaf removal than greenhouse plants, because the splash risk is higher.

Common mistakes

• Stripping the plant to expose the fruit to sun — Ripening is driven by temperature, not light. Bare fruit in full sun scalds — it develops pale, papery, sunken patches — and the plant loses the leaves that were making its sugars.
• Taking every leaf off below the top truss in one session — The plant loses most of its photosynthetic capacity at once. Growth stops, the remaining fruit stays small, and flavour suffers.
• Composting blighted leaves — It survives on living tissue and infected tubers, and a heap that never heats through gives it somewhere to sit until next year's plants go out.

Questions people ask