A controlled humidity chamber will work, but it takes more of your time to see it is properly vented to prevent mold from growing and killing your cuttings. A mist system works in an area with a good air exchange and avoids the fungus problem generally. Al

I'm not sure about your pom's and your kiwi's, but I propagate a bunch of grapes. I use hardwood cuttings of dormant wood in winter. Just cut off some pencil-sized "sticks", poke them in the ground (make sure the up side is up!), or in containers with a potting mix, and in the spring time most of your "sticks" will reward you with an explosion of vegetative and root growth. Transplant (if not already where they belong) the following fall or winter.

No need for bottom heat, mist, humidity chambers etc. EASY!!!

Al, if diseases are the only issue I'm not too worried. I have been propagating a lot of dormant cuttings and have gotten good at eliminating molds by bleach soaks of the cuttings and then copper sprays later.

Re: grapes, I am propagating a bunch of dormant cuttings now and indeed find them very easy. I mainly just want to experiment for fun with the summer cuttings.

Scott

Misting systems are cost prohibitive. The require maintenance, attention and electricity. Humidity systems are affordable and forgiving. I use large clear plastic containers (Sterlite) with several inches of peat moss and perlite in the bottom that is moist but not soggy. For easy viewing and transparency I use saran wrap for the lid. This provides moisture retention and ease of opening the chamber for inspection, access or to adjust the humidity level.

I have found that if there are no water droplets visible in the chamber a light misting form a spray bottle will work to adjust the humidity slow and evenly. Also if there are too many water droplets you simply open a small portion of the cover and give it time to ventilate the excess moisture out.

I have had success with my affordable humidity chamber for propagating greenwood cuttings of pomegranates, grapes and olives.

Mist systems don't have to be expensive: $300 bucks makes a 450 square foot mist yard.

1. DIG interval timer & valve. About $100.
2. 6 fence posts. About 20 bucks.
3. 10 stud length 2x4's. About 20 bucks
4. 7 16 foot 2x4's. About 30 bucks.
5. 200 feet of 75 psi rated 1/2" water line. About $40.
6. 240 low pressure misting jets (About $100 -- leevalley.com. I'm sure there is a cheaper source. They are antelco jets, rebagged.)

The posts and 2x4's are used to make a simple 16' x 16 foot to 16 x 30 foot trellis. Plant the posts. Screw a 2x4 to the side of the post with a 2' overlap. Screw a second one to the side opposite. Screw the top end to a 16' 2x4. The long 2x4 should be between. Use a single screw until you get the other end up too.

At this point you have 3 pi shaped supports in a row, about 15 feet apart. 4 16' 2x4s cross these. These brace the pi trellises from bowing toward each otehr form the tension in the pipe later.

Snake the tubing back and forth on the trellis. Cut scrap wood with a notch that the pipe fits tightly in, and screw these to the trellis over the pipe to keep it still. Or pipe hanging tape. Or those copper saddles uses to secure copper water pipe.

The pipes should be about 3 feet apart. So if you make a 16 x 30, you will need 6 x 30 feet of pipe, plus manifold pipe and connection to timer.

Experiment with a jet to get a handle on the spread, but I think you want them about 18" apart. (Depends on water pressure, and brand of jet.) You want them on both sides of the pipe, so each pipe will have 40 jets -- adjust according to spray pattern. Antelco claims a 0.8 meter diameter, but normally you put sprinklers at a radius apart to compensate for irregular patterns.

Punch and screw in the misting jets. Do a single row on two pipes, facing each other. Lay down some newspapers. Turn the system on. Watch the papers and see if they get wet uniformly. You may have to adjust the spacing which means either 60 more feet of pipe or a hatfull of goof plugs.

The rationale behind 3 foot spacing: If you use standard 21x10 plant trays, you have a 15" aisle between rows of trays. This leaves no tray right under the pipes, which drip in use, and drain when the system turns off. You might be able to stretch this to 3 trays side by side the long way. Experiment. .

Issues:

You may need to make a manifold for the pipes so that it starts and stops reasonably fast.

Every nozzle will drip. This concentrates too much water on whatever is directly underneath. Easiest way is to run your aisles under the pipe.

The ground gets wet. (Surprise!) This can be messy. Cover the ground with old carpet, fuzz side down. Or do the gravel thing.

Misting at the edges is erratic, becuase of breezes. This can be used to harden off cuttings that have gotten a start.

You can compensate somewhat by scrounging sheer curtains, and hanging them around the mist yard. locate them so they are wetted by the mist. Breezes passing through them will be humidified. Run fence wire curtain height from the ground to hang the curtains. Staple the bottom edge to scrap lumber to keep it from blowing. Note: This will NOT be successful in strong winds. You are building this in a sheltered location, right?

You may want to put sunscreen cloth or lath over the top.