Recognize budrot (blossom end rot): Signs, causes & tips

Budrot is every grower's nightmare. At first everything looks perfect, but suddenly the buds start to rot from the inside - and often you only realize it when it's already too late. This invisible enemy can destroy your entire harvest in just a few days! 😱

But don't panic: In this guide, you will learn how to recognize, avoid and combat bud rot at an early stage. From the first warning signs to typical mistakes and effective countermeasures - here you'll find everything you need to know to protect your plants. 🌱🔥

What is bud rot (blossom end rot)?

Bud rot, also known as blossom end rot, is every grower's nemesis. Once it creeps in, this nasty mold spreads rapidly and can ruin an entire harvest. The culprit is the fungus Botrytis cinerea, which feels particularly at home in damp, warm and poorly ventilated conditions.

❌ The main causes of Budrot

• High humidity - damp buds are a paradise for mold
• Too little air circulation - stagnant air promotes the formation of spores
• Densely grown buds - little air inside = perfect climate for fungi
• Sudden temperature changes - condensation on the flowers can be fatal

Particularly dangerous: Budrot eats its way through the buds from the inside out. It is often only noticed when it is too late. That's why it's so important to recognize the first signs early on - and that's exactly what the next section is all about. 👀

Recognizing budrot - the first signs

Budrot is insidious. It starts invisibly, spreads silently and by the time you discover it, it has often already eaten deep into the flower. The problem: the fungus grows from the inside out. From the outside, the plant often still looks healthy, while a putrid process of decay is already underway on the inside.

So that you don't notice that something is wrong when it's already too late, you should regularly take a close look at your plants. It's not enough to just glance over them - you really need to touch the buds , smell them and pull them apart carefully. Sounds drastic? It is! But this is exactly how you can recognize bud rot at an early stage and prevent it from spreading to other plants.

🔍 Typical signs of budrot:

• Color changes on the flowers or sugar leaves
  At first everything looks normal, but suddenly gray, brown or even black spots appear. Particularly treacherous: these discolorations are often not on the surface, but hidden inside the buds.

• A strange, musty smell
  Depending on the strain, healthy cannabis smells fruity, earthy or spicy - but never musty or sweetly rotten. If your plant suddenly emits an unpleasant, muffled odor, you should listen up.

• Soft, mushy spots on the buds
  Buds affected by bud rot lose their compact structure. If you press them gently between two fingers and they feel soft, spongy or moist, this could be an indication of rot.

• Crumbly, dry areas in the flower
  Another warning sign is when certain parts of the flower become brittle and dry, even though the rest of the plant still looks normal. This is a sign that the fungus has already decomposed and hollowed out the plant material.

• Dusty mold coating and spore flight
  If you touch an infested area and suddenly a fine cloud of dust rises from the flower - congratulations, these are mold spores! This means that the fungus has already moved on to the next phase and is continuing to spread.

❗ Important: Budrot spreads quickly! As soon as you notice the first signs, you must act immediately. Cut away affected areas generously and remove them far away from your plants - preferably outside to prevent spores from spreading in the grow environment.

In the next section, we will discuss gray mold - a common confusion with budrot. Because not everything that looks gray is really Botrytis. 👀

Grey mould vs. budrot - recognizing the differences

Many growers confuse bud rot with gray mold, as both types of fungus occur under similar conditions and look quite similar at first glance. However, there are clear differences that determine how you treat the problem.

Here is a practical overview:

🔍 How to recognize whether your plant has budrot or grey mould:

• Is the flower rotten on the inside? → Budrot
• Can you see a fine, gray coating of mold? → Gray mold
• Is the fabric crumbling? → Budrot
• Does a dusty film come off when touched? → Gray mold

While gray mold often only remains on the surface and is easier to remove, budrot can destroy an entire harvest if it is not discovered in time. That's why it's so important to act quickly. In the next section, we'll look at how to spot budrot under a microscope - especially helpful if you're not sure! 🔬

Recognizing budrot under the microscope - A look into the invisible danger

Sometimes it's not so easy to identify budrot with the naked eye - especially in the early stages. This is where a microscope or a good magnifying glass can make all the difference. If you're not sure whether your plant is infested with budrot, it's worth taking a closer look.

🔬 What can you see under the microscope?

• Fungal threads (hyphae) - fine, thread-like structures that run through the plant material
• Spore carriers - Small, roundish structures that contain the dangerous spores
• Spore dust - Tiny, granular particles that are released and dispersed by movement

While healthy flowers show clear trichomes with milky or amber-colored heads under the microscope, infested plant material appears frayed, discolored and often "dusty". As soon as you discover such signs, you should be on high alert!

🧐 When is a microscopic examination worthwhile?

• If you have initial suspicions but do not yet see any clear symptoms
• If you notice discolored or strange smelling spots on the buds
• To make sure that it is not harmless trichome loss or other deposits

💡 Tip: If you don't have a microscope, a strong magnifying glass (at least 60x magnification) is often enough to spot the first signs. An inexpensive USB microscope camera can also help you get a clear picture of the situation.

In the next section, we'll look at why cannabis is particularly susceptible to bud rot and how to avoid typical growing mistakes. 🌱🚨

Cannabis and bud rot - Why are plants so susceptible?

Bud rot can affect many plants, but cannabis is particularly at risk. This is mainly due to the dense, resinous structure of the flowers. If moisture is trapped and there is insufficient air circulation, this creates a perfect climate for the fungus. But there are other factors that increase the risk.

🚨 Typical mistakes that favor Budrot

1. Excessively high humidity in the grow room
   Humidity above 50 % can be problematic, especially in the late flowering phase. It often rises at night because the temperature drops - which is exactly when bud rot likes to strike.

2. Poor ventilation between the buds
   Densely grown plants with large, compact flowers are a paradise for mold. Without sufficient airflow, moisture remains trapped and the fungus can spread undisturbed.

3. Sudden temperature changes
   When warm air meets cold surfaces, condensation forms - exactly what Budrot needs. Particularly dangerous: temperature drops at night.

4. Plants that are too wet due to watering or rain
   In outdoor growing, rain can have fatal consequences if the flowers do not dry quickly enough. Indoors, incorrect watering can also be problematic - never water directly over the flowers!

5. Late harvest with overripe buds
   The longer the plant stands, the higher the risk of bud rot. If you wait too long, you run the risk of the dense flowers starting to rot.

🔥 What can you do?

• Keep the humidity under control - use a hygrometer and keep an eye on it at night
• Good air circulation - position fans so that air flows through the plants
• Thin out plants susceptible to mould - remove lower leaves and superfluous shoots
• Dry immediately after rain - outdoor grows are best provided with rain protection
• Don't harvest too late - the riper the buds, the higher the risk

The next section is about how you can avoid and combat bud rot - because prevention is always better than cure! 🚀

Avoiding and combating budrot - how to save your harvest

Budrot is like the uninvited guest at a party: once it's there, it spreads rapidly and ruins everything. So the best strategy is not to let it in in the first place! But don't worry - with the right measures, you can significantly reduce the risk. And if it does sneak in, there are ways to limit the damage.

🛡 How to prevent budrot

👉 Keep humidity under control
Budrot loves humid conditions. Keep the humidity below 50 %, especially in the late flowering phase. A hygrometer will help you keep an eye on this. If it gets too humid, a dehumidifier or additional airflow can work wonders.

👉 Ensure good ventilation
Stagnant air is mold's best friend. Make sure there is always a gentle breeze blowing through your plants - but not so strong that they are in a storm. Several fans on a low setting are better than one at full power.

👉 Thin out plants regularly
Tightly grown plants = poor air circulation. Remove excess leaves and shoots so that air can circulate better between the buds. This not only helps against mold, but also promotes growth.

👉 Water properly - but not too much!
Avoid watering directly over the buds. Wet buds + warmth = perfect conditions for bud rot. Instead, water directly on the roots and reduce the amount of water a little in the final flowering phase.

👉 Outdoors? Then shelter from the rain!
Rain is the mortal enemy of outdoor grows. If the weather changes, you should either put the plants under a roof or protect them with a transparent tarpaulin. After rain, a gentle flow of air will help them dry out.

Help, Budrot is here! What to do? 😱

If you do discover an infested bud, you should act immediately! Bud rot spreads at lightning speed and can destroy the entire harvest in just a few days.

✅ Remove infested areas generously - Cut off the affected buds with a clean, disinfected tool. Better a little more than too little!
✅ Dispose of the remains safely - Don't just throw them into the room! Take the infested parts out of the grow room or garden immediately, preferably in a sealed bag.
✅ Disinfect the grow room - If the mold was inside, you should clean the entire area with hydrogen peroxide or alcohol to kill spores.
✅ Lower humidity further - If one bud was infested, the others are at risk. Keep lowering the humidity to prevent them from spreading.

💡 Extra tip: Some growers try to save lightly infested buds by drying or even baking them to kill the spores. But honestly? Better not! Inhaling mold spores is extremely unhealthy - get rid of anything that looks suspicious.

Budrot is a real nuisance, but with the right prevention you can save your harvest. Take good care of your plants and prevent mold infestation before it can even start!