• Do you need help identifying a 🌶?
    Is your plant suffering from an unknown issue? 🤧
    Then ask in Identification and Diagnosis.

Flower Drop (no pollen) solved with Humidity

Hey guys, thought I would share how I solved my issue of flowers dropping. For months my indoor Pepper plants have been flowering but have never set any fruit which left me feeling pretty disappointed. I narrowed down the issue to pollen production since the plants were failing to produce any pollen at all. After weeks of varying my feeding, light, temperature, etc. I found out that my humidity was at the 35-40% mark by chance when I found an old hygrometer thermometer combo and put it in my grow chamber. No wonder the plants didn't have any pollen! The flowers were getting desiccated before they could produce.   
 
So I busted out a 9 head mister humidifier and RH controller that I had from an attempt at growing mushrooms. I've gotten the humidity up to 65-70% which seems to be good, any higher and I'm risking mold I think. It bathes my plants in a foggy mist every 15 mins or so for 10 seconds which keeps them hydrated but not wet. It's only been a day since I setup the humidifier and I can already smell the pollen again and see fruit setting on my Caribbean Red and White Fatalii.
 
I'm happy that I'll now have some indoor pods going and I can reliably grow pepper plants through their complete life cycle from Seed to Pods. 
 
It cuts both ways.  Too much humidity, and you get sticky pollen, which doesn't travel well.
.
One more reason why success in growing often boils down to conditions, more than grower skill.  In your case, it's going to fall back on skill, because you've assumed control of all the parameters.
.
Thanks for posting your observation.
 
solid7 said:
It cuts both ways.  Too much humidity, and you get sticky pollen, which doesn't travel well.
.
One more reason why success in growing often boils down to conditions, more than grower skill.  In your case, it's going to fall back on skill, because you've assumed control of all the parameters.
.
Thanks for posting your observation.
I might experiment with lowering the humidity to 60-65% if I don't notice a ton of pollen coming off them. 

I found out that having three levels of plants instead of two, and a soggy floor from a water leak is what gave me the humidity needed for pollen before I moved the the grow chamber. Once it had been moved the plants stopped producing and I couldn't connect the dots. I was baffled since the plants look extremely healthy despite the flower drop. I'd even put two of my LST plants outside and they immediately started to set fruit. Which really made me start to think about why things weren't working indoors. 
 
"Assumed control of all the parameters" is right, I was just thinking about that yesterday. It's been a learning experience figuring out what plants really need to grow and thrive. Now I feel like I finally have full control over the conditions my plants are in. 
 
I live in a really warm and dry climate and don't have any issues with setting fruit.. I do have a pool in my backyard though so maybe that helps with relative humidity..
 
Edmick said:
I live in a really warm and dry climate and don't have any issues with setting fruit.. I do have a pool in my backyard though so maybe that helps with relative humidity..
 
True, but you also have the benefit of unrestricted pollinators.
 
solid7 said:
 
True, but you also have the benefit of unrestricted pollinators.
In which case, I would just hand pollinate instead of spending money on fancy equipment to tweak with humidity control that may not be needed. Peppers grow in a wide range of environments from humid to dry. I guess what I'm say is, I'm not sold on the whole humidity argument. I think it's usually a different underlying cause.
 
Edmick said:
In which case, I would just hand pollinate instead of spending money on fancy equipment to tweak with humidity control that may not be needed. Peppers grow in a wide range of environments from humid to dry. I guess what I'm say is, I'm not sold on the whole humidity argument. I think it's usually a different underlying cause.
 
I've not had to deal with dry climates, but it's definitely an accepted notion in commercial agriculture, that both hot, dry weather, and hot, and humid (or excessively rainy) weather, can affect pollination.
.
For peppers, certainly they're one of less fussy plants.  I have a lot of problems with tomatoes pollinating in summer, relative to humidity.  I've also had problems with other flowering plants getting moldy. (presumably related to pollen not being displaced)
.
It would be interesting to play around with humidity depravation, and see what's real, and what's not.
 
My Peruvian red rocoto set tons of fruit indoors over the winter in pretty low humidity conditions.
I had to diddle all the flowers myself...tons of pollen tho
 
Maybe my plants are spoiled with humidity? We often get rains that will raise the humidity and these plants were in high humidity for most of their life from fall of last year through to this spring. 

I've had months of no pollen on my plants at all. If conditions are right there should be clouds of pollen or at least something I can see on my finger when I touch them.
 
 
I'm fairly convinced that it was a humidity issue. My Scotch brain has as set a fruit since increasing humidity in the grow chamber. Over the last three months it has dropped all its flowers and not set a single pod. I've seriously changed nothing else but the humidity and now it's setting. 
 
Back
Top