Getting ready to pot up some cutting from small bins of Sphagnum Moss and thinking about potting them straight into 1 Gal pots as opposed to cups placed into a closed larger bin. This is my 1^st time trying the Sphagnum moss and wondering how many of you might be potting up direct in pots and skipping the cups. The Cups I have are only 16 oz. 4 ¾ in. deep, but the 20 oz. I found were not any deeper. I don’t stick the cutting all the way to the bottom and leave some potting mix below and assume others do as well? A good percentage of my cutting will have more cutting above soil then I would like, but I have not found deeper cups. I do have the 3x8 poly bags, but I don’t see that working with the fragile root starts on the cutting. I am curious from out of the Sphagnum what others have found most successful. I have had poor success rooting I have mostly used damp paper towel to cup in bin, with a increasing decrease in humidity leaving the bin on increasing periods, but seem to lose most everything after potting up. I keep blaming moisture control and I use close to 50/50 perlite/Pro-mix or other quality soilless mix but I don’t have much success managing cuttings with roots into plants. I know there is a LOT of threads discussing rooting and I have reviewed many of them, but I didn’t home in on one on after removing from Sphagnum what most folks do. Thanks.

think i need to go to the eye doctor things suddenly got small or its this computer.lol

Sorry Martin,

I did have that a bit small and I guess If want responses I better size it up enough so folks can read it. 

Getting ready to pot up some cutting from small bins of Sphagnum Moss and thinking about potting them straight into 1 Gal pots as opposed to cups placed into a closed larger bin. This is my 1st time trying the Sphagnum moss and wondering how many of you might be potting up direct in pots and skipping the cups. The Cups I have are only 16 oz. 4 ¾ in. deep, but the 20 oz. I found were not any deeper. I don’t stick the cutting all the way to the bottom and leave some potting mix below and assume others do as well? A good percentage of my cutting will have more cutting above soil then I would like, but I have not found deeper cups. I do have the 3x8 poly bags, but I don’t see that working with the fragile root starts on the cutting. I am curious from out of the Sphagnum what others have found most successful. I have had poor success rooting I have mostly used damp paper towel to cup in bin, with a increasing decrease in humidity leaving the bin on increasing periods, but seem to lose most everything after potting up. I keep blaming moisture control and I use close to 50/50 perlite/Pro-mix or other quality soilless mix but I don’t have much success managing cuttings with roots into plants. I know there is a LOT of threads discussing rooting and I have reviewed many of them, but I didn’t home in on one on after removing from Sphagnum what most folks do. Thanks.

I think most people go from sphagnum to cups ranging in size from 16 to 32 ounce.  The main reason to do so is that you can get a cheap clear cup pretty easily and see what the roots are doing. 

I don't see any harm in going straight to a pot.  You will not be able to see the progression of the roots, but if you can keep your curiousity at bay, it doesn't really matter. 

First key is to avoid breaking the roots when you put them in the pot or cup.  Second key is to avoid over watering, or letting it get too dry.  Sometimes you can have both at the same time.  The top can get dry, while the bottom is too wet.  I use a 2 gallon fine mist sprayer.  That way the top gets moist, and some trickles down to the bottom.  Certainly not a necessity, but when their in small containers indoors with low humidity, the top can dry out daily, whereas the bottom will probably stay moist.  It's a tricky balance.  Even if you don't get it exactly right most of them should survive anyway. 

Gallon containers take up more space, that is their biggest disadvantage.

Thanks,

I ended up cutting bottom out of the 20 oz. which where the same height but wider and stuffing them into 16 oz. which gained over a couple inches in height. I would not have been able to place the 1 Gal. in the bins I have. Probably would have been easier to look around at some restaurant supply store for taller cups, which I didn’t find at the 3 or 4 places I checked, but I think this will work.

I keep mine under lights or on the window sill with another cup inverted over the top, watching to prevent cooking and burning, then start easing them outside, where they go topless.

Copy/pasted from something I left on a thread at GW, still really close to being completely on topic:

"How large a container can or should be, depends on the relationship between the mass of the plant material you are working with and your choice of soil. We often concern ourselves with "over-potting" (using a container that is too large), but "over-potting" is a term that arises from a lack of a basic understanding about the relationship we will look at, which logically determines appropriate container size.

It's often parroted that you should only move up one container size when "potting-up". The reasoning is, that when potting up to a container more than one size larger, the soil will remain wet too long and cause root rot issues, but it is the size/mass of the plant material you are working with, and the physical properties of the soil you choose that determines both the upper & lower limits of appropriate container size - not a formulaic upward progression of container sizes. In many cases, after root pruning a plant, it may even be appropriate to step down a container size or two, but as you will see, that also depends on the physical properties of the soil you choose.

Plants grown in slow (slow-draining/water-retentive) soils need to be grown in containers with smaller soil volumes so that the plant can use water quickly, allowing air to return to the soil before root issues beyond impaired root function/metabolism become a limiting factor. We know that the anaerobic (airless) conditions that accompany soggy soils quickly kill fine roots and impair root function/metabolism. We also know smaller soil volumes and the root constriction that accompany them cause plants to both extend branches and gain o/a mass much more slowly - a bane if rapid growth is the goal - a boon if growth restriction and a compact plant are what you have your sights set on.

Conversely, rampant growth can be had by growing in very large containers and in very fast soils where frequent watering and fertilizing is required - so it's not that plants rebel at being potted into very large containers per se, but rather, they rebel at being potted into very large containers with a soil that is too slow and water-retentive. This is a key point.

We know that there is an inverse relationship between soil particle size and the height of the perched water table (PWT) in containers. As particle size increases, the height of the PWT decreases, until at about a particle size of just under 1/8 inch, soils will no longer hold perched water. If there is no perched water, the soil is ALWAYS well aerated, even when the soil is at container capacity (fully saturated).

So, if you aim for a soil (like the gritty mix) composed primarily of particles larger than 1/16", there is no upper limit to container size, other than what you can practically manage. The lower size limit will be determined by the soil volume's ability to allow room for roots to 'run' and to furnish water enough to sustain the plant between irrigations. Bearing heavily on this ability is the ratio of fine roots to coarse roots. It takes a minimum amount of fine rootage to support the canopy under high water demand. If the container is full of large roots, there may not be room for a sufficient volume of the fine roots that do all the water/nutrient delivery work and the coarse roots, too. You can grow a very large plant in a very small container if the roots have been well managed and the lion's share of the rootage is fine. You can also grow very small plants, even seedlings, in very large containers if the soil is fast (free-draining and well-aerated) enough that the soil holds no, or very little perched water.

I have just offered clear illustration that the oft repeated advice to 'only pot up one size at a time', only applies when using heavy, water-retentive soils. Those using well-aerated soils are not bound by the same restrictions."

Al 

I would not start any long term plant in a large container.  Roots will tend to grow straight down over brachiating.  When you start them in a smaller container though they will not have very much depth so they'll stretch up and make better use of the horizontal space in your container.  Once the rootball begins to rootbind you can transplant them to a slightly larger container that will now benefit from the much larger surface area covered in roots (since you let it rootbind a little.)  When you graduate plants in this fashion to slightly larger containers as they rootbind you will generate a much more efficient rootball which will pay you dividends later in the plant's life.  It will also make nutrient distribution more efficient for you in terms of cost later on because there are more roots in less area and therefor less nutrients settling in rootless soil, not to mention marginally more efficient energy use in terms of nutrient distribution for your plant.  This will also make root pruning easier down the road.

It's pretty clear to me now that we're branching out into the realm of pseudoscience now - trying to make things sound like science without it really BEING science. In fact, this is beginning to sound like someone I know. 

Roots in container media have the same degree of geotropism (tendency to grow downward) as plants in the ground. The fact is, roots are opportunists, and opportunity trumps tropism every time. Roots simply grow best where they find the proper mix of air, water, and an adequate supply of nutrients. Illustrative of that contention are experiments with red maple that show >75% of the fine feeder roots in the top 12" of soil in spring, and <10% of the volume of fine feeder roots in in the same 12" of soil during summer drought conditions. How efficiently roots colonize container media has nothing to do with container size/volume or shape, and everything to do with the air/water relationship in the media.

Roots cannot over-brachiate, over-bifurcate, over-trifurcate, or over-ramify. You simply cannot have too many fine roots. Fine roots are the plant's work horses. They do the lions share of water and nutrient uptake and are responsible for moving water/nutrients to the canopy. The plant is genetically programmed to increase root ramification to the degree required to support the canopy and immediate new growth - not more, not less.

I'm not sure how in one breath you can say that over-brachiation (increased root density) is bad, and in the next say increased root density is good "It will also make nutrient distribution more efficient for you in terms of cost later on because there are more roots in less area and therefor less nutrients settling in rootless soil, not to mention marginally more efficient energy use in terms of nutrient distribution for your plant."  None of this makes sense to me; and how the plant uses energy is determined by a combination of genetic encoding and (primarily) photoperiod.

"This will also make root pruning easier down the road." I've root pruned many thousands of trees and can't see how a small container makes root pruning easier. It makes it more difficult because it either increases the frequency with which you need to root prune, or because the reduced soil volume increases root congestion.

Appropriate container size/soil volume is determined by soil choice. Water-retentive soils = smaller container so the plant uses water faster & roots don't rot. Fast draining soils, like the 5:1:1 or gritty mix MAXIMIZE growth if you grow in larger soil volumes.

The rule is, root congestion has a fairly insignificant impact on growth/vitality until the point where the root/soil mass can be lifted from the container intact. Just before that point is when conscientous commercial growers usually bump their plants (to larger containers) to prevent diminished growth due to root congestion. If you're growing in a soil that holds little perched water, you can pot a cutting in a 55 gallon drum (if you prefer) without risk of root rot associated with soggy soils. You get far better growth because roots forage in a large soil mass, and you don't have to repot like you would if you stuck the cutting in a soda bottle. ;-) I'm not advocating for cuttings in barrels, only making the point that with the right soil, it can REALLY work for you - but NOT with the wrong soil.

Al