Better to Burn Bud than to Bud Rot

Bud rot, also known as gray mold or botrytis is a mold that thrives in cool, moist conditions. The spores are mostly transmitted by wind and like to attack weak areas of plants like a break or a bend in a stem.

The really terrible thing about bud rot is that it always seems to attack your biggest and best flower growing. This discussion will focus on prevention, identification and remedies.


Indoor gardens can benefit from managing temperature (over 70F) and humidity (<50rH). Outdoors we cant adjust those factors but we can manage by:

Growing in well lit areas, pruning to allow more air and light and watering early in the day to allow moisture to dry up through the daylight hours. If possible, give plants more spacing.

  • Rain can become trapped in your flowers so either covering your flowers during rain, or shaking your plants after a rain can be beneficial. Leaf blowers can also be used.

  • Keeping the growing area free of plant debris and disinfecting tools should be part of your everyday procedure especially this time of year.

  • Fungicides should be avoided in flower. However some stressor reducers like Harvest Miracle can help your plant resist attack and can be used up to 7 days before harvest. Potassium silicate in your nutrient solution is also thought to help plants by thickening the cells walls and making it difficult for mold to take hold


If you search online you will find bud rot can manifest in a number of different ways all over the plant. However, what you will most likely find is bud rot that is inside your flower. So the cola can appear to be drying up, the edges of leaves may brown.

The biggest tell tale is a leaf coming out from your flower that is entirely brown and might be soft and wilted. Where that leaf is bend the flower to open it up and take a look. Mold growing inside the bud will be easy to identify as an ugly gray moldly mass.


There really is no remedy other than to remove and destroy any parts of a flower that are growing mold.


  • Once you identify mold in the flower cut off the affected bud and discard (do not compost). It may be beneficial to use a q-tip to clean the remaining flower at the cut site with isopropyl. Use gloves and disinfect your tools.

  • If you are finding the mold is spreading quickly through your garden it is best to harvest early and dry quickly.

  • When you dry, separate the buds and put into a dry rack (vs hanging branches) to get as much air as possible. Ideally dry at 80F and 45 rH.

October 01, 2020 — TREVOR WILKINSON