perlite/vermiculite soiless mixes

[echinopora]

After accidentally loosing 3/4 the root mass repotting a largish citrus (coir/bark/perlite/compost mix that had compacted 25%) I am willing to make the switch to a lighter airier medium. I thought I had a good grip on the rootball but the thing fractured while moving it to the new pot. I think part of the downfall was using worm castings every couple of weeks as they likely filled in all the gaps in the mix over time. The ingredients for gritty mix seem to be scarce around here, but I live about 30min away from a vermiculite/perlite mine and have access to basically unlimited pumice. I know the hydro guys use a 4:1 perlite/vermiculite mix. Has anyone tried it on longer term plantings or does the perlite break down? how about graded pumice pebble/vermiculite?

Rob

[starling1]

Pearlite is better than pumice for a variety of reasons, the primary ones being that it is cheaper, lighter, has a more stable PH, works better with coir and peat, and delivers water more efficiently to the roots. All professional hydro guys and enthusiasts use verm/pearlite. In a run to waste system, which is what you'd be going for, you can use pearlite/verm/ coir/peat/ at different ratios depending on what you're growing.

If you're using a soiless mix, you shouldn't really be adding anything solid to it at any point for any reason. You need completely liquid feeds. There is a good range of complete feeds that are organic and designed to work with coir/peat based run to waste systems in Australia.

I recommend PMing John (JMC) on this forum, he's pretty savvy with it all.

[echinopora]

Thanks, will do.

How do fertilizer sensitive things like garcinia/jabs do with dilute nutes? How much would you have to dilute to prevent burning?

[starling1]

Thanks, will do.

How do fertilizer sensitive things like garcinia/jabs do with dilute nutes? How much would you have to dilute to prevent burning?

I wouldn't describe jaboticaba as nute sensitive, but garcinias definitely are. The long and short of it is you're probably going to have to go through a process of trial and error a little bit. I am too with growing dragonfruit this way, though thankfully John is doing this also so I can benefit from his experiences. It shouldn't end in disaster if you play it safe with dilution levels and use the right type of nutes.

[Mark in Texas]

After accidentally loosing 3/4 the root mass repotting a largish citrus (coir/bark/perlite/compost mix that had compacted 25%) I am willing to make the switch to a lighter airier medium. I thought I had a good grip on the rootball but the thing fractured while moving it to the new pot. I think part of the downfall was using worm castings every couple of weeks as they likely filled in all the gaps in the mix over time. The ingredients for gritty mix seem to be scarce around here, but I live about 30min away from a vermiculite/perlite mine and have access to basically unlimited pumice. I know the hydro guys use a 4:1 perlite/vermiculite mix. Has anyone tried it on longer term plantings or does the perlite break down? how about graded pumice pebble/vermiculite?

Rob

Something's missing in this equation.  If you had a healthy rootball it should pop out in one piece and not fall apart.  There may be some issues with your watering frequency, pot material, pot size, etc.   I use a 50/50 of inorganics and organics.  Inorganics being mainly vermiculite with washed sand.

[echinopora]

Definitely a problem, which is why I'm looking for a better way. I should have had help is probably the first thing I did wrong, and the compacted mix was hard enough that the roots would not have been happy. The worm castings had really cemented the thing together. A 15 gallon block of crud with a slightly spikey lime tree sticking out of it was awkward. Like starling said it was a bad idea to be adding super fine organics, I should have stuck with liquids. It was in a homemade air pruning half barrel, and the roots were really tangled into the shadecloth on the bottom of the barrel where it was too moist to air prune the roots away, but had enough aeration for them to grow. I also should have repotted much sooner. Because the bottom of the barrel has a rim, most of it does not sit flush on the ground and the area between the barrel and the ground was very rooty as well. Put it all together and yes, something definitely wrong which is the reason to change. Most of the soil would have been to dense and anoxic, and lesser trees would probably just died, but this one just sent a nice thumb thick root right to the bottom where conditions were tolerable and made a mat of roots into the shadecloth that I had ziptied to the barrel. Between the ordeal extracting the thing from a well intentioned but badly designed container, and trying the old bearhug without losing an eye, that thumb thick root snapped about 12 inches below the soil surface. I've put it in the ground and we will see what happens. So lessons learned, no fine organics, air pruning pots should be on a stand to ventilate the underside, get help with big jobs and lighter mixes in really big containers.

[Tropicaliste]

It's important to weigh a lot of factors before switching your soil. If you live where you need to bring your plants in for the cold temperatures, then you don't want it too gritty. Unles you want to water everyday, and you run a good misty humidifier. The leaves and roots will dry up. Trust me.

You may want to increase your perlite, but not keep enough that will trap water in. If you live where you can water them with a hose, and get to them every other day, then you'll probably be fine in a perlite verm mix.

[greenman62]

Rob,
did you feed them liquids like fish ?
What percent of the media was worm castings ?
My thinking is the worms should have given you the microbes you needed
but they need food to keep going.
Was it store bought worm  castings, or home-made ?
sorry for the barrage of questions,
i ask, cos i just started using my own castings.

personally, i dont like soil-less media
maybe it is the combination of the sun hitting the black containers,
high heat, and occasional dry spells, but they dry out quickly for me
and if i dont feed them properly, there are more problems.
and i found if peat-moss drys out too much, its a pain to re-hydrate.

I have a lot of papaya and other plants that hate wet conditions
for more than a couple of hours, and have a very diverse set of plants,
thats one reason ive been putting as much as i can in the ground,
but i still have at least 60 containers, all having different requirements,
and i am a lazy bastard

Brad

[echinopora]

I was adding worm castings to the pot, probably every 2 weeks or so when I rotated the trays in the worm farm. The original mix was just sifted composted bark, coir, coarse compost, perlite about 40/40/10/10. It got top dressed with sugar cane mulch when I had it around. It also got coffee grounds now and again. It was fertilized with osmocote controlled release and blood/bone + potash. I've been trying to get everything out of pots but I've got some jaboticaba and rheedia's that will have to be in pots for a while, and I'm in the humid subtropics so the Mediterraneans stay in pots too. I let it dry out a bit before repotting and that likely contributed to the rock like consistency.

Rob