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In the bag - air pruning

I'm pretty new to air pruning so I'm very much in the experimental stage. I thought I'd post some thoughts as I go and maybe get feedback from those who are more experienced.

An interesting point is that what we (or at least I) was taught in school to be the "scientific method" was actually "the experimental method". Science does not require experiment. The field of "positive Psychology" was developed using something they called the Crutchfield-Mendicini protocol (that's from memory, but I can find a reference if you want), no experiment involved. Doing science only requires following just one of the steps for the process. The one that goes, "Submit your results for peer review." So, what we are doing on this forum is science, the science of growing figs.

Anyway, air pruning strikes me as being a big step up on sliced bread. Root pruning is a drag. I hate it when I pull a pot off and find a few roots going down the center and a layer of roots running around just inside the pot with a big donut of, relatively, root free dirt in-between. I feel like I've got to be setting the plant way back by cutting off such a big percentage of it's roots. The dense balls of fine root hairs that you get from air pruning just seem so much better.

I can't afford those fancy plastic air pruning pots. I went through that huge thread on the pot growers forum and they were experimenting with weed barrier cloth. I couldn't be sure just which cloth they were using. Woven apparently doesn't work well and when they used multiple layers it didn't work as well. Everybody likes to brag about using the highest quality cloth but I'm thinking,"Hey, you want the roots to go through it, but, it's designed to be a barrier." It seems to me that the cheap stuff that isn't as good a barrier would be better for this purpose.

The cheapest weed barrier cloth I could find was at Dollar General. $5 for a 50 ft. roll. For my first pots I split it up the middle into 18" strips and had my wife sew it into tubes. I gathered in the bottom with wide stitches around the edge and pulled it into a purse with a 1" strip of Pellon Thermolan TP970 through the center for a wick. You can see my fig cuttings in them at  http://figs4funforum.websitetoolbox.com/post/kiddy-pool-sip-6838413?pid=1282247326#post1282247326

The standard for DIY air pruning bags seems to be reusable Walmart bags which cost $.50 apiece. I get 100 of these out of a $5 roll so these are an order of magnitude cheaper. Of course, they are smaller, but still they are more the size I need at this point.

When I repot up from these I'll cut 12" dia. circles for the bottoms. With the hem, that puts the circumference right at the width of the roll. If I go 12" high with the sides I'll get 3 bags out of 4' of fabric. That works out to just over 13 cent a bag. Pay twice as much for better fabric and you're still at half the price of a Walmart bag. Yes, you do have the work of sewing them up, but if you don't want to work maybe you shouldn't be in gardening anyway. I'd rather spend my gardening budget on plants rather than pots, myself.

Anyway, I started some elder cuttings in newspaper pots back in late Nov., early Dec. and moved them up to these pots late Jan. Here's a picture of the roots coming through and air pruning.

2 elder roots airprune.JPG 

Those are your basic plastic plate sips. I have to water every couple of days, from the top and bottom... but they are growing like weeds.

And, they can poke a sprout right through that cheap barrier cloth.

sprout thru bag.JPG 

Here are a couple of unknowns, that are about 7 or 8 years old. What with the move and all they haven't been up-potted/root pruned in about 5 years. All last year's growth got winter killed and I've snapped it off. What's left is flexible so I think it's still alive. You can see the stobs where they've been froze back many times before. I'm debating pruning them back to two or three main trunks and working towards a better shape, but don't know if I should be doing a lot more cutting on them so soon after this big root prune.

lg & sm U in pots.JPG 

Pretty much solid roots... no donut of unused dirt.

lg U unpotted.JPG 

lg U rt pruned.JPG 

I used a 16" dia. bag with 3, 1" strips of wick, and a 25/75 mix of perlite and compost/dirt mix. I used an old galvanized pan for a sip. I potted it in place because its pretty easy to put your finger through these bags when they are full of dirt.

pot rdy for lg U.JPG 

When I got the plant in I put a fence around it and wrapped it in microfoam. One problem with a black pot/bag is that the sun on it can get the roots too hot. A bag can also evaporate off an awful lot of water, especially with a dry wind blowing. The fence and microfoam is to protect the bag from sun, wind, and critters while leaving a gap for the air pruning to take place.

lg U done.JPG 

Then I put the smaller plant in a smaller bag but the same setup.

sm U pttd rdy to cvr.JPG 

Okay, I didn't get a picture of them all done. but this is close, it's just short the foam on the little one. I didn't put the pipes in because I can see to pour water down the gap to fill this one... and I can add them later easily enough if I need to.

lg&sm U pttd lg dn.JPG 

One thing I'm looking for here is how the sip effects the air prune. It's intuitive that air pruning won't work in a humidity chamber. I tried it anyway, and sure enough, the roots didn't dry and die in the high humidity they just kept going. I don't think that will happen with this large plant, but I'm going to be watching the smaller one and the ones in that kiddy pool very closely. When I up-pot them I want to move them onto a rain gutter sip. I think that will be less likely to put too much humidity around the bag because it a much narrower reservoir. If this one or the kiddy pool starts to show a problem I'll let it go dry for a day or so between watering to let the air pruning happen.

So that's it! Adventures in figland. I haven't seen where anyone is doing anything quite like it... but it seems like it ought to work pretty well. I'll keep you posted. Show me how you improve on this.


I think this is great! I haven't decided yet if I will do something like this later when my figs get bigger or just plant in ground. With this long drought we've been in, I don't know yet.

Thanks for this a great tutorial and I like the pics of each step. Helps to better understand :)

  Thanks for all the great pictures.  " worth a thousand words" for sure!  I'll be interested any updates.

For our plants its the ole fashion root prune yes its a pain a real pain.
The way i see it the heart of the rootball does not get root pruned with the airpots and those
types only the outer roots.

We have used root pruning pots for a long time.  Amazing the amount of roots they produce!  I love those pots!  Nice photos!

We used some bags black inside and white outside to reflect sun.  Perfection!!  Now that we've moved, no need for pots or bags.  Everything in ground.

Suzi

How did those bags hold up? They look much better than cheap black plastic pots for the plants. I see more sizes here,  http://www.wormsway.com/en/Sunleaves

I want to keep going with air pruning, but I'm looking for something better for that outside layer. I have some foil-foam-foil that I was going to use but the foam I put on was handy, and I got it for free. We'll see how it holds up. I want trees in the ground, but I'm going to have to keep potted backups too.

This setup is too fragile to move around. I expect to repot it before winter and I going to have to put them in something that I can move. That's the big reason I made the bags so close to the size of the pots that they were in, and didn't put them both in the same size bags. By the time all the cuttings I have coming get ready to move up I want to have gained some experience from these guys.

I'm already learning that I need more wick than I gave the cuttings. I had a couple start to wilt. The bags felt moist and after all the "over watering kills them" I've been reading here I was pretty nervous, but a little water perked them right up.

Hi greysmith,
With that setup, that would me my fear : the mix not holding/keeping enough water and moisture.
Imagine that pot in full wind blow, the air would go through the dirt and dry the potting mix really quick ...

I would think of it like that:
Do you really need to have the roots exposed all the time and air prune all year round, or once a week or in a while would be enough to air prune the roots ... after all, people of the pots :) do prune once a year ...
I would have a plastic barel around - say an 80 liters trashcan bottomless - and push it over the tree down to the potting bag for water and freshness keeping - and pulling it out for air pruning once a week or one week in the month ...
This way you would need less wicking and a bit less watering.

Air pruning is a well established technique, people do it all the time. But they top water, and then complain about how much they have to water. Wrapping the bag with plastic and taking it off periodically to air prune is an accepted technique. There are plastic pots made to air prune. They have less area given to holes but the shape of the plastic leads the roots to the holes. But, they are expensive, and made from black plastic.

I'm just trying to combine technologies in a less expensive, and labor intensive way. The reason that everybody isn't doing it may be that it doesn't work and I just haven't done enough research to find that out. There comes a point in the research when it seems simpler to just try it. But, then you should post your results so the next guy can find it right at the start of his research.There's a lot about air pruning in the back threads of this forum, but it's in dribs and drabs and you have to filter through a lot of dross to find it. I should have been cut-n-pasting it into a file as I researched so I could lay it all out with references. But then, when I started I didn't know how much I would find, or how fragmented it would be. I'm trying to make this thread what I was looking for when I started.

As an example check out this thread on combining air pruning with air layering.  http://figs4funforum.websitetoolbox.com/post/air-propagator-air-layering-unique-system-5933728

I used a well drained potting mix and watered daily with a drip system.  I had many wine grape vines and figs in those containers because I knew we were moving in a year or so.  The Sunleaves containers were temporary for us, and they don't last over a year, but they do a great job of making a vigorous plant with lots of roots, none root bound, that can easily be replanted into a larger container, or in our case, in ground.  JD used duct tape when the roots pushed too hard to keep the bag intact.  LOL!!

Here is my mix:

For 100+ degree Desert Heat:

4 parts Turface
3 parts bark
2 parts crushed Gran I Grit (Grower Size) or #2 cherrystone  
1 part vermiculite

Plant a little high, and after the planting is established, mulch heavily with crushed granite.

1 Tbsp gypsum per gallon of soil

Did I mention that an electrical drip system with varied stations is the best money spent for all plants. 

Suzi

Here's an update on the problem of losing moisture. We just had a couple of sunny days with temperatures around 80 and a lot of wind. Mid-morning 1st day I noticed one of the VdB wilting. I gave it some water. An hour or two later, when I checked, all the VdB and MBVS were wilting and some of the HC. I watered everybody, and then watered them again later in the afternoon. The second day they were all perky first thing in the morning but were wilting by mid-morning. I watered them, and watered them, and watered them, that wind would have them dry again in about two hours. The pool filled up from all the watering till the bottom of the bags were just touching it, and that seemed to help more than all the top watering. I was able to get the others to perk up by constant top watering, but the VdB needed to get it from both sides.

I took them in just before sundown, and they were all perked back up by then. We have heavy weather, and then a hard frost, moving through. When I put them back out I'm going to wrap the bags in plastic as a wind barrier. The bigger plants that have a wind barrier are still dormant (or dead). I gave them some water anyway, just because I was so spooked by what was happening to the others.

The figs are showing remarkably good sense by staying dormant (or dead). The bloom on the apples is just opening. The bloom on the peaches has just about run it's course. We're pretty much at the point of maximum tenderness. The weather service is calling for 26F tomorrow night, and I usually get about 5 under what they call. I don't expect much from the orchard this year. I've been planting elder cuttings that I started inside over the winter. Some of them had started to bloom too. At least they are small enough to cover.

Greysmith,
Thanks for starting this topic and sharing.
IMO, your problem is wick sizing. The wick is too small for the root mass / container size. Most kidde pool type SIPs have the entire bag bottom in 1 - 2 inches of water.
Good Luck.



A few posts from earlier related Topics
http://figs4funforum.websitetoolbox.com/post/show_single_post?pid=1281080008&postcount=4
http://figs4funforum.websitetoolbox.com/post/show_single_post?pid=1277982582&postcount=27

And I'm currently testing Hydroponics and SIPs in combination with air root pruning. This is also to see if the fig tree can be maintained in a smaller pot size, in conjunction with limb pruning (note the spun Landscape Fabric Liners in the attached picture).
http://figs4funforum.websitetoolbox.com/post/show_single_post?pid=1282152231&postcount=1
Olympian_BurntRidge_4-13-14.jpg

2012 we had very hot summer with constant temp over 100. only way for me to keep my VdB happy without watering three times a day was having it sit in a pan full of water. even with that, i had to fill up the pan twice a day. that's with drip system going every day.

These are some great videos. It's snowing here this morning, so, all the potted plants came in to party down in my living space. I'll be making some changes when I set back up outside.

The dogwood just started blooming, so this is dogwood winter. We still have blackberry winter to go... and a possibility of frost then. I was talking to an Amish guy and he said something about that last polar vortex being "stump winter". I hadn't heard that term before, but since I'm heating with wood I knew exactly what it meant. In a winter like this one there comes a point when you really have to dig to find something to put in the stove

I had seen setups where they just set the bag in the pool and periodically put water to the bottom to let it soak up. I didn't put a drain in the pool because I suspected I'd need to change it to something like that... and sure enough.

I'm worried about these pots being so small. There's a lot of surface area to volume so they can dry out really fast, and there's not enough height or mass for the moisture to stratify, so there's no safe place for roots if it bottom stays too wet. Maybe I should have started with bigger bags and counted on the air pruning to fill the roots out in them. I'm afraid to try changing them now, till they do get some good roots established.

My unknown would wilt when the temperature got up around 100, and no amount of water would perk it up. Of course, it was root bound. I've been planning to keep the VdB in pot. It's good to know ahead of time that they need mechanisms in place for heavy watering in high heat conditions.

We do get some high heat here, I've been really wanting to get some Florea going because it sounds like the ideal variety for my climate... but I haven't seen it be available since I've been looking for it.

I started this thread in the beginning of April. Thought I'd update it, as of the beginning of Sept., to show how it's been working so far.

Here's what they look like now.

f in grnd and bg pots.JPG

Those in ground looked like this f in grnd beginning.JPG  All the stems on all these plants were dead from the hard winter and I pruned them back to the ground when they started coming up from the roots. They came up thick. I thinned them, and thinned them, and thinned them. I've been pinching them back and tying some of the branches to spread them out. When they go dormant I'm going to thin them again and get serious about shaping. I want them low and bushy but I want to hold them to just a couple of main trunks coming out of the ground so I have room to clean and weed around them. The ones in the pots have figs on them, the ones in ground don't. That's something to keep in mind when you plant in ground.


Thanks for that update.  Since I'm rather close to you, I've been following your experiments.  Hope to read more on your methods.

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