Bud rot, or Botrytis Cinerea, is a common fungus that many cannabis growers will come across in their lifetime. The fungus can grow when people are unfamiliar with the techniques of humidity control and air circulation. The fungus causes the nutrient and water delivery system in the plant to become compromised. This can result can be so bad that it can kill off the entire plant. How fast does bud rot spread? How to keep your weed save? What spray can you use? We help you out!

Cannabis plants that have contracted bud rot need to be dealt with quickly and safely. Depending upon how many plants you are growing, bud rot can completely wipe out your harvest in a matter of a week.

Cannabis Flowering Bud

Bud rot affects the buds and the leaves of cannabis plants. The fungus starts close to the stem and then moves to the rest of the plant. It will then spread quickly to the flowers and leaves. It will ruin all of your hard work.

How Do I Identify Bud Rot?

When it first appears, bud rot attacks the stem of your cannabis plant. The stem will appear mushy and gray. As the infection spreads, the leaves will appear wilted, yellow, and burnt. It is hard to spot it at first because the fungus takes hold of the inside of the plant, where it is difficult to spot. By the time you do spot it, it is usually already spreading.

While looking for bud rot it is important to check between the leaves of the buds. Check to see if the core is rotting. If it is, you will need to quarantine that plant. You will need to bag it and remove it from all other plants. Then move on to the next plant and do the same thing. If it is infected, it has to go. Keep repeating this until you have checked every plant.

Some plants with botrytis will develop grey webbing or white spores. The spores are a really big concern as they can spread easily through the air, water, or on you. To help to reduce the chance of infection by spores, you should change clothes between rooms. You should also have clothing set aside for each room.

What Causes Bud Rot?

Bud rot is a gray mold. It develops in places that have poor circulation and are high in humidity. Both of these conditions allow the mold to flourish. Bud rot takes root slowly in this environment. But, once it does take root, it can spread very quickly.

Cannabis Plant Flower

Botrytis is common with larger, dense buds and plants. The reason for this is that the denser, bigger plants and buds trap moisture inside them. Also, because they are dense, they inhibit air from freely flowing through them. This creates the perfect environment for fungus to grow in. What causes bud rot in cannabis plants?

The best way to avoid bud rot is to have an understanding of what causes it to thrive in the first place. The following is a list of factors that can help bud rot to form, and to thrive: High humidity, mild to warm temperatures, poor ventilation, dense leaves, and dense buds .

Cannabis Leaf

You want to make sure to plant your plants with some distance between them. Plants that are in close quarters are in more danger from the spread of bud rot than plants that have a healthy distance between them.

How Do I Treat Bud Rot

After Botrytis has set in, it is very difficult to treat the plants and reverse the infection. If more than one plant has bud rot, it is possible that your entire grow area is infected. If you wish to stop the spread, remove all infected plants immediately. It is possible that you can save some of your cannabis plants. Now, many growers will choose to harvest their uninfected plants, in order to try to save some of their yield.

If you catch your plants at the very first sign of bud rot, you can try to remove the infected buds. You do not want to expose any other plants to them. Wear gloves while removing the infected buds and leaves. Put them into a sealed container. You want to stop any potential spores from spreading. Sanitize anything used on the plants, or throw them out.

If your plants are flowering, don’t use any fungicides. This will change the buds drastically. They will have altered taste, smell, and look.

Outdoor Grows

Outdoor Growing Cannabis

Because of the unique challenges of growing outdoors, outdoor cannabis plants can be saturated by rain or dew. Controlling humidity outside can be a real issue. Because of the lack of humidity control around their cannabis plants, outdoor growers can be plagued by bud rot. Using an air blower of some sort can help to dry out your plants and introduce air circulation.

Prevention of Bud Rot

Controlling the environment where your cannabis plants are growing is the primary method to preventing bud rot.  The following list will help to curb the appearance of bud rot on your plants. Always remember that prevention of something is better than curing something. 

Control the Humidity

Circulating air will help to remove some moisture from the plants (see below). But if you want to really assist in getting rid of the moisture in the air, try a dehumidifier. There are plenty of them on the market. Just remember to get a decent to a good one. They will help to reduce the conditions that fungi love to grow in.

Circulate Air

Fan

Clean, fresh air should be constantly moved through the room you are growing in. This will help to prevent the spread of spores. If you are able to vent the room, this is better. This will assist in removing any spores from your room altogether.

Space Those Plants Apart

Your cannabis plants are like people. They require a little space. If your plants are crowded together, this can create a situation in which the fungus will grow quickly. The closeness of the plants will restrict airflow. This will allow the fungus to spread along with the plant it is on and to the plants next to it. On top of this, the moisture on the plants will have a harder time evaporating. Plants should not be touching. This is asking for an issue.

Inspect Your Cannabis

Check your plants daily. If you are really worried, check them twice a day. Get rid of any standing water. Remove any unnecessary plant material. Really give the plants a good inspection. If you do this, you may be able to catch the infection early on. If you are really good, you may even stop any before they get a foothold.

Final Words

Bud Rot can be deadly to your cannabis crop. Following the guide above, you may be able to stop it in its tracks or prevent it entirely. Just remember to stay vigilant and act quickly if you discover any bud rot on your cannabis. I hope this guide has helped you with some questions about bud rot.

Besides bud rot, it is also important to make sure your plants don't experience any root rot. We also have an article on how to avoid that here.

Happy Growing!