How to Stop Botrytis

Botrytis, also called grey mould, is a disease caused by a fungus which gets into wounds or cuts in plants and infects them. It can also infect healthy plants as well, especially under humid conditions. Grey mould canaffects lots of types of plants, particularly apples, strawberries, blackberries, beans, cucumbers, courgettes, lettuce and tomatoes. It's particularly prevalent for plants grown under glass (ie in a greenhouse or cold frame) due to humid, often overcrowded conditions.Botrytis can also affect Chrysanthemum, Cyclamen, Pelargonium, Primula and more. 

What does Botrytis look like? How do I know if my plants have Botrytis?

Botrytis resembles a fuzzy grey-brown mould, and appears on decaying buds, leaves, flowers or fruit. You may also notice a few other symptoms.

  • If humidity is low, infections may be contained within discrete spots, but if it is high they can spread rapidly
  • Above-ground parts of plants, particularly buds and flowers, may shrivel and die
  • On soft fruit, particularly gooseberries, Botrytis infection kills the plant's branches, but the fuzzy grey mould is seldom evident
  • On strawberries, grapes and sometimes other fruits, Botrytis infection leads to a soft brown rot, often as the fruit is ripening

How to Avoid Botrytis - Avoiding grey mould - botrytis on grapes

How to avoid Botrytis

Prevention is key - if you can avoid the conditions that grey mould will thrive in, your plants have a better chance of survival.

Botrytis likes humid, overcrowded conditions, especially greenhouses. Make sure you have adequate ventilation - installing a Greenhouse Autovent (£34.99) is a great way of maintaining an even temperature in your greenhouse - built with durable metal, this auto vent will automatically open and close with temperature changes. It's also worth looking at a greenhouse fan - these will heat your greenhouse during winter and spring and can be used as a fan during the summer, circulating the air to prevent fungus and mould. 

Keep plants dry to avoid a humidity, using a solution such as our self watering planters or Click & Drip watering systems will help to stop overwatering your plants. 

Another tip for avoiding Botrytis is hygiene - it's so important especially in greenhouses. Remove dead and dying leaves, buds and flowers from plants promptly all year round, and get rid of them to a compost heap or green bin - don't leave dead plant material lying around. Clean between your plants and give your whole greenhouse a good scrub and clean between seasons. 

 Clean your greenhouse and keep it tidy of plant debris to avoid botrytis

How to treat botrytis

If your plants have succumbed to Botrytis, you'll need to work quickly to treat it. There's no real cure for the grey mould, and no there's no fungicide or chemical control currently available to control botrytis. It's really a case of acting quickly and maintaining healthy conditions for your plants. 

  1. Remove the diseased parts of the plant as soon as you spot them, including any leaves or fruit you see lying on the ground.
  2. Burn or dispose of the prunings completely to avoid spreading the disease.
  3. Disinfect your cutting tools.
  4. Ensure there’s sufficient ventilation and enough breathing space between plants, whether you're growing outside or in a greenhouse. If your plants are in a greenhouse or cold frame, open doors, roof or side vents to encourage air flow. If your plants are too crowded, consider digging up and replanting a couple to allow more room.

How to treat Botrytis in your greenhouse

You May Like:

Anti-Leaf Disease Kit - £10.00

Essence is a brew of friendly bacteria which prevents and cures botrytis, mildew and other leaf diseases.

The friendly bacteria out-compete the leaf diseases and colonise the surface of the plant so there’s no room for new leaf diseases to take up residency.

Automatically opens and closes with temperature changes to release humidity in your greenhouse.

This 2KW electric heater and fan in one has winter heating and summer cooling modes.

It has very low running costs and distributes air quickly and evenly, so you can maintain the temperature of your greenhouse or polytunnel without spending a fortune on energy bills. The heater has a cable length of 1.9m.

Quadgrow Self Watering Planter - £46.00

This planter waters plants from the roots with no overwatering, avoiding damp soil which could encourage all sorts of diseases. Harvests are 2x bigger when grown in a Quadgrow planter compared with grow bags or pots because it automatically waters your plants for 14 days at a time.