Tomato plant cover and blight

Updated: October 2026

A tomato plant cover does not stop blight. In a wet UK summer the question is narrower: can a ventilated film cover keep rain off the leaves for long enough to reduce the pressure, and what happens if you shut it. Late blight is Phytophthora infestans, the same organism as potato blight. The Products Compared editorial team is following the RHS and Gardeners' World accounts, checked for this page on 16 October 2026, not a product trial. The tomato plant cover comparison is where the covers are listed. If you buy through our links, we may earn a commission at no extra cost to you.

Our top picks

Badge	Product	Rain cover	Vents	Type	Note	Price	Offer
Best overall	VOUNOT VOUNOT tomato grow house, white	Yes, PE claimed waterproof	Not stated	Film growhouse	9.0	about £23.49	View offer
Best value	DIVCHI DIVCHI tomato growhouse	Yes, film cover	Not stated	Film growhouse	8.2	about £15.47	View offer
Alternative	Tierra Garden Haxnicks pop-up tomato cloche	Yes, polypropylene cover	Yes, adjustable vents	Pop-up tomato cloche	7.8	about £20.99	View offer

Best overall

VOUNOT VOUNOT tomato grow house, white

9.0/10about £23.49

View offer

Best value

DIVCHI DIVCHI tomato growhouse

8.2/10about £15.47

View offer

Alternative

Tierra Garden Haxnicks pop-up tomato cloche

7.8/10about £20.99

View offer

On this page

1.What late blight needs
2.What a film cover can and cannot do
3.Mesh, and a cover you leave shut
4.Potatoes, disposal, and when to stop guessing

What late blight needs

Blight needs living tissue, spores, and leaves that stay wet. The spores move on the wind. Gardeners' World and the RHS both treat prolonged wetness on the leaf as the condition that lets an infection take in a warm, wet British summer. Outdoor tomatoes get that wetness from rain. A plant under cover is watered at the roots, so the leaves can stay dry when the path is soaked. Keeping leaves dry is the only mechanism a cover can borrow. If you are unsure, and you have potatoes to store, use the RHS tomato blight page rather than guessing from a sentence.

What a film cover can and cannot do

A well-ventilated cloche can reduce tomato blight by reducing wetting by rain. That is the RHS sentence: a reduction, with a condition, not a guarantee. Spores that get in through doors or vents can be just as damaging, and high humidity inside usually speeds the symptoms. Gardeners' World says a bad year can still reach plants if doors and vents stay open, because open is how the spores enter, and shut is how the humidity builds. A film house or a polypropylene cloche can put a skin between the shower and the leaf. You still open it to water, to stop the air going stale, and to let insects at the flowers. A cover left shut after a warm afternoon trades rain-wet leaves for condensation. How to open the door is on how to use a tomato plant cover. A maker line that says a cloche will protect against blight is not a finding. This comparison includes no blight trial.

Testsieger

VOUNOT VOUNOT tomato grow house, white

9.0/10about £23.49

View offer

Mesh, and a cover you leave shut

Mesh lets rain through. The RHS treats insect mesh as adding little warmth, and these listings describe breathable netting, not a waterproof skin. A bird bag can be the right tool when blackbirds are taking fruit. It does not keep the leaf dry, so it is not a blight cover. The film-versus-mesh choice is on the tomato plant cover buying guide. A film cover you leave shut is a different mistake. The RHS says soft growth under cloches encourages Botrytis, grey mould, unless ventilation is very efficient. Grey mould is not late blight, and it will still ruin trusses. Open the door or the vent. If the only way to water is to lift the cloche, lift it, water the compost, and put it back with a vent cracked on a warm day.

Potatoes, disposal, and when to stop guessing

If the plants have late blight, do not put them on the home compost heap. Gardeners' World points to council green waste, where the heap runs hotter, and says not to reuse that soil for tomatoes or potatoes for at least four years. The RHS options are to bury infected material deeply, to use the council green waste, or to burn it where local rules allow. Do not light a bonfire because a forum said to. On the RHS account, councils do not take polythene from a spent cover in ordinary home recycling, so reuse a sound sheet. That is not a reason to keep a mouldy cover over a sick plant. This page will not invent a spray programme. Ventilated film can keep rain off the leaves. It does not stop blight.

Common questions

Does a tomato plant cover stop blight?

No. The RHS says a well-ventilated cloche can reduce tomato blight by reducing rain on the leaves. Spores can still enter a door or a vent. No listing here was trialled against blight.

Why does rain on the leaves matter?

Late blight infection is tied to leaves that stay wet. A film cover can keep the shower on the plastic while you water the compost. Mesh does not do this.

Can blight still get into a growhouse?

Yes. Spores entering through doors or vents can be just as damaging, and high humidity usually speeds symptoms. You still open the house, because a shut one brings grey mould. You close it for the rain, not for the whole summer.

Is mesh any help against blight?

Not as a rain cover. Mesh is for birds and insects, and rain passes through it. If the worry is a wet July, you want film you can vent.

What happens if I keep the film shut in humid weather?

You raise the chance of grey mould. The RHS links soft, humid growth under cloches to Botrytis when ventilation is poor. That is a different disease from late blight. Open a door or a vent on warm days, and drop the cover when rain is due.

Should I grow tomatoes next to potatoes?

It is a bad pairing. Both are hosts of Phytophthora infestans, and spores move on the wind from one to the other. A cover on the tomatoes does not protect the potato leaves. Give them separate ground.

Tomato greenhouse or cloche