DIY misting sensor for cuttings

[Oldhilly51]

Well, went to Bunnings this AM with a shopping list for the cover for the misting box. I had this great design using square tube and plastic corners. Things were going OK until I looked at the prices and lengths of tube available. I needed 14 lengths @ 1M long. These were $8.80 each and the 14 corner brackets were over $2.50 each.
Needless to say, my finances remain in tact and Bunnings are no richer. I just have to work on a different design. Perhaps plastic conduit will do the job?
Do you use gravel/scoria for bedding for the pots to sit on and is this bedding material sitting in a water filled trough? This would keep the humidity up and save on water a little bit but would it keep things a bit on the cool side?
I will post some pictures when I get something near completion provided I can work out how to do the posting pictures thing.

[shibui]

Do you use gravel/scoria for bedding for the pots to sit on and is this bedding material sitting in a water filled trough? This would keep the humidity up and save on water a little bit but would it keep things a bit on the cool side?

See previous pictures for a look at the bedding in my propagating bed. The last photo shows the cliplock decking bent up so that the tray holds water. In the propagating area these trays are filled to the top with gravel so that the pots sit above the water rather than in it. The aim is to keep humidity high but as I have said not sure if it is necessary but works for me. I have not considered whether the gravel tray cools things or not. Once the gravel and water warm up they should actually hold heat??? Previously I had polystyrene boxes filled with gravel. With drain holes at the bottom these did not hold any water, just gravel damp from misting (see right of 3rd image). Cuttings were less successful on those so I took them away and put in the cliplock gravel trays. Results definitely improved.

Well, went to Bunnings this AM with a shopping list for the cover for the misting box. I had this great design using square tube and plastic corners.

Is this to be a mini greenhouse cover over the whole thing? If so, cheapest frame is bows of poly pipe. PVC is more rigid but costs a bit more. You'll need 25mm+ poly pine for enough strength but 13mm pvc is strong enough to be self supporting.
Drive a piece of steel rod (or equivalent) into the ground on either side. Slip ends of the tube over these so you have an upside down u. Add a couple more in line to give the required length, tie some more shorter lengths between individual bows at the highest point to provide some rigidity then drape plastic greenhouse cover over - similar to the poly tunnels you see at nurseries or flower farms but you can determine the height, width and length of the structure. I also use these to support bird net over the ripening berries and smaller trees so the birds don't eat all the produce.
Curved ribs make it a little more difficult to add a door but a couple more vertical and a horizontal strut at the front will allow a door. For smaller ones just lift up the plastic to get in or maybe have the front open?

[Oldhilly51]

This is going to be a self-contained box under cover on a shady veranda. I tracked down some 6mm white acrylic sheet for 3 sides and got some 20mm aluminum angle and "T" sections to make a lid that I can cover with some thin, clear and semi-flexible acrylic sheet. It's own weight should be enough to keep it closed and some sort of flexible material, perhaps something like seat belt webbing, should be fine to act as a hinge. To keep the board of management happy I will have to work out some sort of overflow drain and waste water disposal but that shouldn't be much of a drama.
Then it's just connect the water and electricity and find something green (and legal) to grow in there.
If the Police turn up I guess I will have to explain that the device is intended for legitimate purposes. Perhaps growing tomatoes in it isn't a good idea?

[Oldhilly51]

Well, things are getting closer. The misting sprays may cover a 1M diameter circle but not at 400mm above the soil surface. I am getting to know where all the micro-irrigation fittings are hidden at Bunnings.
Do I need to allow for ventilation to the growing area? I have a 100mm gap across the lower front of the enclosure that I need to fill (the "repository of things too good to throw away", i.e. the scrap pile, didn't have quite the right size of clear acrylic sheet in stock) so I need to join a bit in across the bottom. Should I allow for some sort of vent in this area?
The good news is that the "electronic leaf" actually works! The bad news is that I have no idea how to calibrate it. It seems quite sensitive at the moment, needing only a second or so duration of the spray before the balance arm swings down. Will this be enough?
Should get the plastic work finished tomorrow, then I can work on the misting patterns to get better coverage.
Then there are the photos to worry about. I may need help there.

[fossil finder]

G'day Oldhilli51
Might be a matter of trimming the surface area of electronic leaf to make it slower to switch off....or was that on?...or make the arm of the electronic leaf shorter.

Sent from my SM-T530 using Tapatalk

[Oldhilly51]

Perhaps what I need to do is to add more weight to the counterweight, i.e., move it outward to make it so that the leaf needs more water on it to get it to swing downwards. I think. At least, well, that seems logical to me.
Anyway.........I managed to work out how to upload pictures to my photo album gallery thingo place whatever it's called. The box and it's "leaf" are there in all their glory, slightly out of focus abut they are there. If there is to be a "Leaf Mk.2" it would be slightly different, probably made from 50mm ally tube and flat sheet for the frame and 10mm ally tube for the arm. The electronics would be hidden in a water resistant box and I would use different types of cables and plugs but We always seem to be wiser after the event, don't we?
Thanks for the help along the way, the "boss" isn't ready for her cuttings yet so I am going to try my hand at propagating some Grevillia cuttings from plants that need a prune.
Thanks again for the help.

[shibui]

Should I allow for some sort of vent in this area?

Yes definitely need some operable vents in the cover so it does not overheat in warmer weather but can be closed up to hold heat in when temps are lower. Operable vents may also be useful to adjust the airflow and humidity but that will probably need some trial and error.

It seems quite sensitive at the moment, needing only a second or so duration of the spray before the balance arm swings down. Will this be enough?

Even 1 sec spray should be ok because the whole purpose of the leaf is to deliver water whenever the leaves of the cuttings get dry. 1 sec every 2 min or 5 sec every 10 min still achieves the same result. Moving the counterweight back will lift the leaf and require more water on it to lower and may be enough to give longer spray times but I think Fossil finder may be correct - leaf too large = catch too much water too quick. I had to trim mine down to make it work better.

Good luck with the grevillea cuttings. Not always the easiest to strike but hope you get something from them.
Some more tips:
Use rooting compound to increase success. I have found that the gel is better for me, especially for hard to strike species.
Use propagating mix to strike cuttings. Potting mix has nutrients and pathogens that will love the misting area and will attack the cuttings before they get a chance to root. Propagating mix is sterile and inert. Usually made from perlite and peat or sand and peat, sometimes straight propagating sand will be ok.

[Oldhilly51]

Thanks for the reply Shibui. I have the feeling that some ventilation may be needed. With nothing in the chamber there seems to be little evaporation. The "leaf" is as wet this afternoon as it was when I went out this morning. Mind you, the 50mm of Scoria lining the chamber was pretty wet to start off with and today was overcast and pretty humid so I feel that evaporation would have been fairly low anyway. There will be a bit of trial and error involved, probably lots of error to start off with.
For the cuttings, I was going to use some coarse sand with a little Perlite and either Sphagnum moss or CocoPeat to add a bit of body to the mix and stop the sand running out of the tubes. I am going to give "Yates Clonex" purple gel a go, just to see how things turn out. I have some second-hand tubes that I can use to get started. I think I should give them a bath in bleach to clean them up before I start. Lord knows that could be living in them at the moment, although I did check them for Redbacks before I picked them up!
Thanks for the help and advice.

[shibui]

I think I should give them a bath in bleach to clean them up before I start. Lord knows that could be living in them at the moment, although I did check them for Redbacks before I picked them up!

Great that you recognise the possible problems of reusing any propagating equipment. I wash all used pots in 10% bleach before reusing to minimise the risk of pathogens passing on from infected pots. Propagating mix and pots are microwaved for 10 min to bring the temp up above 72C if I plan to reuse.

I had a look at the photos. I think you could trim the leaf back by nearly half to make it less sensitive. Leaf on mine is 90x190mm.

My propagating mix is 50/50 perlite/cocopeat. Perlite provides air and peat retains moisture. I think sphagnum will make it hard to insert the cuttings but find whatever works with what you have on hand.

[Oldhilly51]

Once again, thanks for the advice Shibui. I will trim a little from the edges of the "leaf". this should make it, as you suggest, less sensitive. When I started I had no idea how things were going to work and was basing my plans on other beam balance scales that I have used recently.
It's interesting that you don't use sand in your Propagating mix. I looked at the Perlite and it seemed quite large-grained and the cocopeat, well, I could run that through the blender and take the lumps out of it because it is really chunky as it comes out of the bag! When all the small dairy farms were closing down around here about 20 years ago there were so many handy gadgets that went to landfill that I could be using today it almost makes me cry. An old corn grinder would have been great for grinding up the cocopeat!
On the subject of cocopeat, there is a big tomato growing operation nearby that uses bags of cocopeat as a growing medium. They use literally hundreds, perhaps thousands, of the things and sell them off cheaply when the tomatoes are finished. I was thinking of using this material as a garden soil amendment once I sieve the rock out of the sand and clay that we call "soil" around here. What are the chances of bringing soil-borne diseases (and I doubt that an operation of this size would have disease problems) into the garden and would those diseases, if there were any, only be a problem for tomato type plants? The cocopeat, as it comes from the farm, is soaked in whatever hydroponic growing chemical they use and there are 4 tomato root balls in each bag of fiber.

[shibui]

Cocopeat should be quite fine and fibrous. There are several different forms available. One is a chunky one for mulch. Some have added fertiliser which is also not good for cuttings. The one you want is just cocopeat with nothing added. Not sure how the blender will process the chunks. coir is notoriously hard to cut or break up.
I find a coarse grained perlite is best. Grains about 4-6 mm, possibly a little larger. The aim is to have plenty of spaces in the mix for air and to allow excess water to drain out. If you use sand coarse grains are also desirable for the same reason.

I think the used tomato bags should be ok for the garden. They should be infused with nutrients from the hydroponic solution which should reduce the nitrogen drawdown as the fibre rots in your soil but do not be surprised if you need to add some more nitrogen some time.
I guess a large commercial operation would not tolerate disease getting started in their crop so should be safe to use. Any disease present diseases should be specific to tomato and close relatives.

[Oldhilly51]

I didn't realise there were 2 types of cocopeat, I had only seen the lumpy stuff they use for mulch. A while ago I bought some "White Peat" (which is actually brown) and it is very fine once you break up the lumps that are made when the material is compressed in the bag. I also have some Perlite from up in Queensland, both of which I am adding to my garden "soil" so I will use what I have and hope for the best.
The pots I scrounged are soaking in bleach solution but I think I will go and see the local horticultural suppliers and get a couple of the trays that hold the pots upright otherwise I feel that I am going to be more than just annoyed when things just keep falling over all the time!
Thanks for the advice on the ex-tomato farm peat. I thought that the diseases, if there were any, would be tomato-specific but I didn't really know. Best to ask a silly question than to remain a fool.
Thanks again.

[Oldhilly51]

Well, until the "Board of Management" decides on the type of bonsai material she wants propagating, I pruned one of my "trifid" Grevillias and set about 40 cuttings. With luck I should get about 10% success rate. Better to learn on something simple rather than on one of the "Board of Management's" bonsai stock.
Thanks for all the advice,
Dennis.
ps. Photo of the completed propagation box in my album.

[dince]

Shibui, what a great contribution you have made, and you have certainly created some interest! I have just joined this forum on account of finding your original article when googling balance arm sprayers, having been scared off at the commercial price of them. I recall seeing them in operation in a nursery I worked in as a teenager, and was fascinated. Now I am am going to try my hand at making one, based on your excellent instructions, and the valuable input from others. Thank you.

[shibui]

Good luck mate There is always a bit of trial and error but the journey is often more valuable than the destination.