DIY Mist propagator. Work in progress

There has been a request for instructions on duplicating a mist propagator. Here is my version.

Tools. Harbor freight Rotary tool (poor mans dremel) $9.49
Harbor Freight hole saw $9.99
Sterilite 6 quart $1.00 x2
pond mister
any of these will due. LED not required. Quality is variable. I had one fail on me in two weeks. Amazon return policy was no hassle but I am spending a little more for one with better reviews.

cycle Timer 30 minutes off 60 minutes on $9

or Programmable timer $14.80

3.2cm 32mm net pots $5
You can also get them on Amazon you might need to use different size cutout hole.

1/2" drill bit and smaller to create pilot wholes.
Glue, I am using gorilla glue. Contact cement should work just as well.

Using the cutout tool. Flip the lid over and cut out the center of the lid. Leave the cross bars and corners uncut. They provide structure support

I used the 1 1/4" (32mm) cut out tool on the other lid.
Sand the top of both lids. If your using gorilla glue you need moister to create the bond.

Start with a pilot whole and move up 2 or 3 times till you reach 1/2" hole.

Set the lid on the base the top of the lids together and a weight on the top box.

To be completed.

I need to cut vent holes in the top container and use the left over white lid plastic to make them adjustable.


One tip here, when using the hole saw bits, once the pilot hole is drilled run them backwards to prevent the teeth from catching and ripping the plastic. This generates heat and basically melts the holes in the plastic lid.


Thinking about a similar project myself. I am planning on using a big plastic (I think 24ct) egg holder instead of a lid with cutouts. The target will be blueberry cuttings.

Has anyone used a humidity sensor in lieu of the timer? It is far less expensive to use a timer ($10-$15) vs the humidity sensor (~$40) but I’m wondering if results are better either way… I’m almost leaning towards just buying 2 timers assuming one will break and have a backup ready to go.

Also- pond mister vs. humidifier vs essential oil diffuser? I have a humidifier already that I am planning to set up underneath the cuttings but an essential oil diffuser could be a cheap choice if you don’t have a humidifier.

I’ll post pictures once I get started. How did your cuttings go the first time around @lordkiwi?

Is that cut baby bottle lids I see you put the cuttings in for the gooseberry thread? How did that go with removing them?

Links? what sensor are you thinking about?
I think the problem with selecting a humidity sensor is you need to find one that will work with a small volume of air or build a larger system so there is more air space to read.

The baby bottle nipples, lol. I improvised with what I had at the time. They were a terrible idea. I mean it would have worked better if I split them down the side but removing air roots though a hole just doesn’t work.

In the end in just couldn’t transfer these cuttings from air roots to soil. Thats why I plan to use bigger cups with soil free medium like Diotomatious earth and perlite.

I’m surprised there’s a humidity-controlled power switch for that little, tbh. Can you share the link to the product you’re considering? I’m using a Raspberry Pi Zero W to turn on heat lamps for pet cages in my greenhouse, and the sensor chip does also have a humidity sensor, though I’m not using that part. Here are the components I’m using for this sensor-based power switch:

Raspberry pi zero w to control it all ($10, but currently out of stock):

Temperature and humidity sensor (the one I use is discontinued but here’s a similar one for $9):

Controllable switch ($33 but currently out of stock):

I guese the 2 Raspberry pie’s i have had sitting on the shelf for 7 years could be put to use for something.

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Inkbird Humidity Controller IHC200 Humidistat Mushroom Greenhouse Pre Wired Outlet Dual Stage Humidifier Dehumidifier

This is what I found. Seems like a good product if it actually works.

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Yup! Looks like mostly good reviews, though here’s one issue raised in the top review that could be problematic for using it where the goal is very high humidity, like in a misting chamber:

The problem with this sensor is that the plastic casing of the sensor allows moisture to bead up on its surface and stay there, falsely giving you a reading for near 90% humidity or even above. It’s not an easy fix because the only thing I’ve found to try and correct this issue is wiping the sensor casing down with a dry, sterilized towel twice a day.

I know many standalone humidity sensors include onboard heaters to periodically dry the sensor off, like this one:

The sensor also has an on-board heater that can be controlled on and off to help evaporate condensation on the sensing element. Of course, temperature sensing will not be accurate with the heater on.

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I never got into the building my own electronics thing, although I’ve replaced my own phone screens successfully in the past and am not afraid to try new things if it will save me some money. I’m not sure that it would be worth the time commitment on this one for me personally if an existing solution is only 40 bucks, or even the timer option for much less. It would be fun though as a hobby project and probably more customizable too.

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Yeah, this was not my first pi project, and I don’t recommend the hobby to anyone who isn’t already caught in its grip. In my case I already had everything but the $32 switch left over from other failed tinkering projects, so it was an excuse to buy a new tinker toy.

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After some further research and asking around (thanks for the lead @Drew51), I found that @Bradybb has already succeeded in the blueberry propagation quest. Some blueberry variety talk mainly Sweetcrisp and Springhigh my favorites - #208 by Bradybb

I also found these cheap little misters from aliexpress for 4 bucks each US $2.38 44%OFF | Portable Mini UFO Negative Ion Humidifier USB Air Humidifier Purifier Aroma Diffuser Steam for Home Purifier Diffuser Steam

I figure buying a bunch of those is cheap enough that some are bound to last awhile…


Interesting design.I might get some.

Anyone know of a readymade mister set up that would work for blueberries or honeyberries?

Brady I placed an order for 10. You can’t beat the price, I found a different listing for around 2.50 each including shipping. Replacement parts are available too very cheap, but I expect 10 to last awhile.

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Limited-time deal: Inkbird Humidity Controller IHC200 Humidistat Mushroom Greenhouse Pre Wired Outlet Dual Stage Humidifier Dehumidifier

Lightening deal, almost claimed @Bradybb @lordkiwi @northwoodswis4

The Inkbird controller is on sale again. Will go fast.

pass for now. To many other projects.