Ottawan.  FMD is the expert here, but here's my 2cents.  

I target the "roots" section to be about in the center of the cup vertically.  Yeah, it'll be much more moist toward the bottom, than the top.  The roots will grow to wherever they are the happiest.

That is a lot more than 2cents for me, James.

I'll keep everyone posted on how mine perform, but what I've seen so far, is astounding.

The suggestion by Frank is very useful and easily made.
The reason I asked the question was that if the principle is moisture ingression through the soil upward as needed then using an inch deep saucer (or more depending on the rooting pot height) under the rooting pot should achieve similar environment for the roots (may be except the frequency of watering).

James, I don't see the need for a humidity dome especially if most of the cutting is burried in the potting media. Still, it would probably not hurt to have one.

Akram, I suppose a well constructed pot and saucer system could be as effective, but for me nothing beats the all-in-one concept championed by the earthbox people.

 One of the biggest misunderstandings of this system is the misuse of potting media. You cannot use soil! That will only get you a boggy mess at the bottom of the pot with zero wicking and rotting roots. With the proper medium (mixture of peat, perlite, etc), the water is wicked up evenly throughout the  mixture and you will not have a perched water table. Imagine the freedom the roots are granted being able to go where ever they want and drink as much as they want 24-7. Add to that a localized source of food that the roots can access 24-7 and you have a very happy plant.

James, your potting mix is fine. Potting mix is not potting soil. You can buy it or make your own. Peat refers to peat moss from peat bogs. Coir can substitute for peat.

Ratios can vary but 70:15:15 is often used (peat:perlite:vermiculite) There are endless variations. Just no soil.

Clearly, I've lost all sanity....

7 Bryant Dark, 4 Joe Dark.

 

Fantastic information!  I have to give this a try. It is so heartbreaking to see those cups die. All that hard work!  Thank you for the ideas.

James, crazy indeed...like a fox!

Sarah, let us know how it works for you.

I'm definitely going to try this so thanks for the post Frank and the variation in design, James! One thing that many have stressed on the forum is the need for aeration of the roots i.e. the need for several large holes in the side of the cup.  Apparently, this system allows enough oxygen to get to the roots even with the cover over the top of the cup and only one hole in the side.  Perhaps the need for the holes in a conventional rooting cup has more to do this allowing the soil to dry out rather than allowing oxygen to get in.

My only question is where is a good place to find 32 oz styrofoam cups with lids?  I don't frequent fast food joints very much but maybe I'll make an exception to pick up a few of these cups.  I did a bit of on-line shopping but could not find reasonable quantities - 1000 is too many!

Very nice information, thanks for sharing.
Tam

I think McDonalds large cups are styrophone.

All of mine are plastic and I got them from Dickeys BBQ, Fuzzy Taco and McAllister's Deli.  The ones from McAllister's, I found about 30 of them at once in the dumpster when I was looking for 5 gal pickle buckets.  I like those because they are clear and I can more easily monitor the state of the roots.  I keep planning to stop by and talk to the manager to see if he can just save me a stack of used cups that people leave behind.

I expect to be able to reuse them, though I may have to replace the reservoir cup and straw.

James,

I am not sure that clear is good for the roots unless you cover them with smth. I keep watching my cuttings in the cups separated into 2 groups, one is clear uncovered and one is inserted into the black pots. The roots in the dark are much stronger and longer while the roots subjected to the light are thinner. I just covered the clear cups after they have been like that for about 2 weeks.

yeah.. i'm planning to wrap some foil around them.  Just haven't had a chance yet.  Still, it will allow me to check on them now and then.

OK, so I've collected most or all of what I need to make a mini-SIP very similar to Frank's design as well as something like James' design in his first pic of post #17.  James, since you have done it both ways which design do you prefer?  The advantage with your first design (Keurig cup as a wick) is that it allows for more soil mix to fit into the 32 oz cup and it does not require the presence of either the short horizontal straw or the long vertical straw.

I'm still undecided on which one I like the best.  I ended up sticking a straw between the inner and outer cups of mine so I don't have to remove the inner cup for refilling the reservoir.  Both seem to work just as well for growing.

Here's the pro's for and cons for each one as I see it.

FMD's version Pros:  Looks better.  Uses less 32oz cups.

FMD's version Cons: slightly smaller soil volume (not really an issue), a little harder to make, can't see the water level, can't place directly on window sill's w/o some sort of drip protection from the overflow tube.

My version Pros:  Using a clear outer cup and opaque inner cup helps protect roots from light but allows to see water level, slightly larger soil volume (doesn't matter), a little easier to make, no fear of drips on window sill.

My version Cons: uses more 32 oz cups.  Looks a little ghetto.  seems heaver, thought I know it can't be by much.

With that said, I only have one of mine and 13 of FMD's with cuttings growing.  I didn't want to waste my cups.  If you have a place to put them (like setting them on a tray) where you don't mind a little water drippage, I'd go with FMD's version.  If you want to put them all along your window sills w/o worrying about water damage, go with mine.

Just found this source for 32oz deli containers that should work well. I know there was a link a while back to purchase these in a case of 500. This is a case of 240. After shipping it came to 24 cents each. Including lids.

http://www.webstaurantstore.com/32-oz-microwavable-plastic-deli-container-with-lid-240-case/128HRD32%20%20%20%20COMBO240.html

Hi Frank, 2 questions:

1. Am a little confused by pic 5- according to my understanding, the majority of the 8 oz cup minus the top ring should be placed upside down at the bottom of the 32 oz cup, but in pic 5, it looks like only a small portion of the 8 oz cup is left-is that a deceptive photo or have I misunderstood something?

2. I have checked the thread, but I cannot find your exact soil formula.  Is it 50% peat moss 50% perlite, or what?

Thanks very much for your help!

Rafael

Hi Rafael,

Picture 5 does not show the proper depth. The size of the 8 oz cup used for the reservoir does not change after the top is trimmed. You don't really need a huge water reservoir for these mini SIPs since they are to be used for the early stages of rooting. The initial watering will last a month or more depending on the the growth of the plant. If you have to water daily, it is time to up-pot to regular one gallon or larger containers.

Just to be precise, we do not use the word "soil" to describe the growing medium. Soil implies dirt, silt, organic matter, bacteria, fungi etc that all come from the ground. 
Any good potting mix from a garden center or box store is adequate. You can roll your own using peat moss, perlite, vermiculite, coconut coir etc at various ratios.
I personally like the 80:20 ratio of peat moss to perlite, but I am sure 50:50 would work also.

Frank

Thank you Frank for your erudite response-I will be more careful when referring to the growing medium!

I love the streamlined concept of 'planting' a cutting and theoretically not having to do anything more than monitor it till its time to move to larger pots. May have to have some of my students do an experiment along these lines with a couple different experimental groups to test multiple variables. Thanks for sharing a great idea! 

Here's my variation on the same theme using the materials that I could more easily find.  Note that the images came out in reverse order for some reason.  The yogurt cup has three vertical slits that don't quite reach the top or bottom of the cup.  I decided to put a number of small holes in the bottom of the yogurt cup so that when it is turned upside-down inside the SIP it will facilitate gas exchange between the soil and the outside.  I'm not sure if this matters but I figured it couldn't hurt.

Thanks for the pics, Rewton.

Rewton, very nice.
I like the holes in the yogurt cup. As you say, it can't hurt.
One could also put holes in the bigger container above the water reservoir for better oxygenation of the roots.