Safely recognize and contain Bud Red in cannabis

## Introduction

**Botrytis cinerea** causes the dreaded flower rot in cannabis, often referred to as **bud rot** or **grey mold**. The fungus mainly attacks dense, moist flowers and can spread unnoticed from the inside to the outside. This is particularly critical in the **flowering phase**, because compact buds, high plant mass and local moisture nests come together there. This guide focuses exclusively on **detection, containment and prevention of Botrytis**.

## Typical symptoms of Botrytis

Early signs are often difficult to see because the infestation starts **inside the flower**.

### Common signs

- Individual **sugar leaves suddenly wilt** and appear gray-brown or dry

- Small leaf parts can be **easily pulled out of the flower**

- Inside the buds, **grey to brownish, dead plant tissue** appears

- Later, a **gray fluffy spore coating** develops

- Infested flowers lose firmness and appear **muddy or crumbly**

### Differentiation from other problems

- Powdery mildew** usually appears as a white, powdery coating on the surface of leaves or flowers, not primarily deep in the bud.

- Nutrient problems** do not cause the typical gray, putrid decomposition inside the flower.

- Mechanical damage** can cause brown spots, but does not form the characteristic mold spot with spore mass.

## Why botrytis develops

Botrytis is mainly favored by **high humidity, poor air circulation and long periods of dampness**. The fungus exploits damaged or densely packed plant tissue particularly easily.

### Important risk factors

- Too high relative humidity** in the flower

- Stagnant air** within dense plant stands

- Very **compact flower structure**

- Condensation or permanently damp flower surfaces

- Dead plant material in the crop

- Injuries due to handling, pests or unclean pruning

## Immediate measures in case of infestation

If you discover Botrytis, the most important thing is to act quickly and cleanly**. The aim is not to cure the infested blossom, but to **stop the spread**.

### 1. remove infested flowers

- Cut affected buds **generously back into the healthy tissue with a safe distance**.

- Remove not only the visible core, but also adjacent material if discoloration or soft spots are visible.

- Work carefully so that as few spores as possible are stirred up.

### 2. treat plants in isolation

- Treat infested plants **last**, not first.

- Do not touch healthy flowers after contact with infested material until you have changed gloves or cleaned your hands.

### 3. dispose of infested material safely

- Do **not reuse** mold-infested blossoms.

- Place directly in a bag and remove from the grow area.

- Do not leave open in the room, as spores are easily spread.

## Correct climate specifically

The most important countermeasure is an environment in which Botrytis germinates less easily and spreads more slowly.

### Particularly important in the flowering phase

- **Reduce relative humidity**, especially with dense flower masses

- **Improve air exchange** through sufficiently dimensioned exhaust air

- **Create gentle air movement** in and under the canopy without permanently blowing strongly on flowers

- Avoid temperature peaks and strong fluctuations, as they can promote localized humidity

### Practical measures

- Do not place plants too close together

- Remove dense, dead or clearly moldy plant material immediately

- Identify damp zones in the room, such as corners without air movement

- Use hygrometers at flower height instead of just on the room floor or in the supply air

## Hygiene after the procedure

After removing infested buds, the **spore load** must be reduced as much as possible.

### Important

- Disinfect scissors and tools after each cut on infested material

- Change gloves regularly

- Completely remove plant debris, fallen leaves and mold material

- Clean work surfaces in the grow room

## What you should not do

- **Do not** try to save heavily infested buds

- **Do not** consume or process moldy buds

- **Don't** spread spores unnecessarily through hectic shaking or rough handling

- **Do not** assume that the infestation is only superficially visible

## Prevention against renewed infestation

Botrytis prevention is above all **climate and stock management**.

### Preventive basic rules

- Ensure controlled humidity in the **flowering phase**

- Ensure even air circulation between and within the plants

- Check plants regularly for wilted sugar leaves and suspicious spots inside the bud

- Avoid injuries to flowers as far as possible

- Maintain clean working practices and consistent removal of dead plant parts

## Conclusion

Botrytis is one of the most dangerous fungal diseases in cannabis cultivation because it can quickly render flowers unusable. Early detection, immediate removal of infected areas, clean hygiene and a dry, well-ventilated flowering climate** are crucial. The earlier you intervene, the greater the chance of protecting the rest of the crop.

## Pro Tips

- Always check dense buds from the inside as well.

- Withered sugar leaves are often an early warning sign.

- Disinfect scissors after every infested cut.

- Always treat diseased plants last.

- Never consume mold-infested buds.