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MagicalMedic

Has anyone investigated which fertilisers may be best for cacti?

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It seems there is a fair bit of info on fertilisers for cacti and some info on particular nutrients they might need, but there still doesn't seem to be much consensus here, with everyone using different stuff. Does anyone have some good in-depth references for what fertilisers and soil work best for cacti, including info about their specific nutritional requirements? (Pedro's in particular)

I'm also considering running a little experiment, whereby I start with say 20 cuttings at of the same size and of the same type of cactus, divide them into four of five groups, plant them all in the same standardised soil (but in separate pots) where they will all be exposed to the same amount of sun, but then allocate a different fertiliser mixture to each group, making sure that each group receives only that one same fertiliser mix as they grow. I can then watch how each group develops and report what fertiliser works best in my experiment.

Have any of you already done something like this? Or read about is somewhere?

Edited by MagicalMedic

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I tried to do something similar regarding the efficacy of using rooting hormone on pachanoi cuttings. However, all the cuttings were slightly different weights and sizes, which would complicate my attempts to weigh them after a year or so and determine if there were any real effecs. I eventually decided to abandon the project.

If you go ahead with it, you'll need to think about how you'll quantify the performance of your plants. You could always just judge by looking at them, but this isn't very precise. More precise would be to measure their height from the soil line, but this isn't very precise either. If you were really serious, you could dig them up after a year or so and then weight them. Perhaps you could even weight the cleaned and removed roots separately by cutting them off. You could then simply re-root them as though they were cuttings. If you were REALLY serious, you might want to take precise measurements of the weight of the plants before you start fertilizing them, so that you could express their weight after one year (or whatever period) as a percentage relative to their original weight.

If you do decide to go about this very seriously, and if you want, I could run some statistical tests on your data. This would reveal insights as to whether the differences between groups are statistically significant or not. However, these tests won't be very reliable if you only have 4-5 plants in each group. if you could raise it up to 10-15 that would be better.

Anyway, perhaps I'm being a bit overzealous! Just thought I'd offer, as I find this issue interesting. Do keep this post updated!

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i cant seem to go wrong with miracle grow and coconut milk, so awesome as iv got 7 pups coming up on one 30 cm cutting. pics to come soon.

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Miracle grow is awesome, 'tis what I use for establish plants and cacti where it's not possible to dig in manure pellets and when it's too unsightly to mulch with manure. Miracle grow has a good balance of NPK and trace elements.

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I tried to do something similar regarding the efficacy of using rooting hormone on pachanoi cuttings. However, all the cuttings were slightly different weights and sizes, which would complicate my attempts to weigh them after a year or so and determine if there were any real effecs.

Sounds cool, bummer it didn't work out. Yeah I would have the same problem with consistency at the beginning, but weighing them wouldn't be a big deal to begin with and it could potentially be done at the end. You're right about the statistical analysis, it's a great idea but power would be very low with the kind of numbers we're talking about.

overzealous

:) always my tendency too, it'd be great to conduct a well controlled experiment but realistically I don't have the number of cacti nor the stability of routine to be super reliable. I'm going to work on it though

Thanks for the other recommendations too I'm going to see what I can source

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i cant seem to go wrong with miracle grow and coconut milk, so awesome as iv got 7 pups coming up on one 30 cm cutting. pics to come soon.

Tell us more about the coconut milk? i never heard of it

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Yes, I too am curious. Do you mean coconut 'water', i.e. liquid endosperm?

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Yeah I'm interested to hear about that to someone posted about coconut milk for pupping a while ago but haven't posted results yet

I've been using chook pellets with pretty good results I've got between 3 and 6 new pups on all my stock plants even small ones

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yeah i read it in a older post a while back and asked my friend who has a nursery and he said yeah its all good for any sort of plant if you want it to branch an stuff. but like i said 7 pups (5 at the on the top and 2 base) on a 30 cm pedro is pretty positive evidence for me. note the top had been cut6 months ago and only 1 pup come up from the cut, but i removed that pup 3 weeks ago now i have 7. i can put a pic up for the none believers

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Are we talking canned coconut milk here? Do you dilute it?

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Miracle grow is awesome,

Seems like there are a few different formulas available - http://www.scotts.com/smg/catalog/productCategoryLanding.jsp;jsessionid=38CCBDBCEE058C07C86E14D7DE7D5491?itemId=cat50010&navAction=jump

Are you using the all purpose one?

I'm intrigued by the coconut milk idea too! Definitely going to give that a go real soon! I found this topic on the matter for those who are interested:

http://www.shaman-australis.com/forum/index.php?showtopic=28323

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I have only used all purpose Miracl grow (water soluble)

I feed most of my plants that are in pots with it not just my cacti

If I dont feed my cacti regularly during summer they will start to yellow but if the get regular feeds the stay nice and green.

I cant say what difference it makes to over all growth as I have allways fertilized through the growing season.

Cheers

Got

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One more question - how often does one apply coconut milk? Once only? Once a month? That's how often I fertilize my cacti in growing season.

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I have done some various testing, and so far I've had pretty awesome results with a mixture of (estimating percentages):

• Blood and bone 65%

• 4:8:6 potato fertilizer 25-30%

• Trace elements mixture 5-10%

This mix seems to need a lot of watering, as the blood and bone doesn't tend to dissolve well with infrequent waterings. I have had no insect problems so far (apart from snails).

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Coconut water is being used for micropropagation so its full of nutrients. Just in the process of getting a good supply of it in good amounts because i wanna germinate seeds on a soilless growth medium. Potato water is another thing thats potentially a good source of nutrients.

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trichs: sulphate of potash, blood n bone, dolomite lime, gypsum, compost teas (incl. microbial mixes incl. humic/fulvic acids, am finding gogo juice to be quite good), manures, worm farm liquids / castings, liquid feeds of fish emulsions and seaweeds, sometimes some mineral based liquid fert, whatever i feel like and is handy.

I've been trying to source rock dust for years for topical and soil mixes, just can't seem to find a source, due to go to a rural farm supply so will be trying then.

Just moving into mycorrhizal inoculants, particularly planned for seedlings, though also will water into mature plants. This will reduce need for ferts even more.

Don't really need much quantity wise small amounts go a long way, diversity is good, just aim to get the soil healthy, feed at appropriate times and everything works well. If you feed too much, you'll just end up salting up the medium and flushing out excess, wasting your time and money.

Edited by gerbil

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I've been trying to source rock dust for years for topical and soil mixes, just can't seem to find a source, due to go to a rural farm supply so will be trying then.

Look up FCRD (Fisher Creek Rock Dust). They deliver and the product works wonders.

Just moving into mycorrhizal inoculants, particularly planned for seedlings, though also will water into mature plants. This will reduce need for ferts even more.

Likewise. I was think of buying some just tonight actually. Having a healthy soil ecosystem is the most important thing you can do for the long term health of plants.

I've never used synthetic fertilisers for my cacti and never will, regardless of what they may be able to achieve.

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ah cheers for that, will have a look into that mob, i'm surprised that there isn't a wide availability in melbourne given our volcanic plains in the west, i assume on the farms that get the rock rollers in, they just crush the rocks in situ and feed back into the soil. But it's frustrating, the garden shows crap on about trace elements and rock dust, yet everywhere i ask i just get blank stares, then rarely if you find a source for something it's overpriced and in ridiculous small quantity.

I'm about to trial mycoapply maxx, WA source, it's really quite cheap if used appropriately (well so my theory goes) will probably be sending out some small samples soon, just waiting on some seed to arrive to accompany it.

On top of all that, if not home made, biochar would be up there too, again commercial sources i've seen are small and overpriced, best off get getting a permit for a suburban backyard burn which is on the cards eventually.

agree with the synthetics, i try to get natural mineral based products and organic based, but often realise they are probably chemically treated in processing or have a part of natural elements with synthetic additives, advertising is funny 'based' is a very deceptive word even though it's clear that it could have anything else in it when you think about it, it's difficult to keep up with it all and or get reliable info from suppliers, even if the chemicals are natural, sorta like glutamates additive in food, natural source but unnatural proportions and processing. I try my best though. Often my education is lacking though so i can fool myself. Even 'certified' organic can be quite deceptive, our classification can be quite silly from what i've heard about some of the rulings.

Thanks for the direction with the rock dust.

Edited by gerbil

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Yeah, I was in the same boat with the rock dust. Saw some crusher dust down on the south coast once, but didn't get it at the time, only to later wish I had. Still, the FCRD really is an excellent product. I had a couple of plants with chlorosis which I treated wit that rockdust. One had marked improvements within a week, which eventually resulting in the entire plant exploding which axillary buds; the other plant remained the same until it started growing again a couple of weeks back and then exhibited the same marked improvements that the other plant did. Treated a few of my cardamom plants yesterday too, so will see how they respond. I'm planning on giving it too all my plants when I next have a couple of hours spare to make it up in solution and water them all with it.

That's the exact inoculant I was planning on getting! Reckon I will get it and do some trials on it too. Will be good to see how our results compare. I'd like to see how it works when pretreating seeds before sowing, but also on all my other plants.'

Biochar would be good to have a decent supply of. Could collect a few bags worth after a bushfire without really denting the supply. I used to mix it in with my cactus mixes until I ran out. Would like to get more again.

Edit: typos

Edited by tripsis

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Nobel did some overview of studies of growth limiting factors and various fertilizers, nothing spectacular but he did illustrate N as a major limiting factor in fast growing cacti.

I prefer ammonium phosphate as a fertilizer for Trichocereus.

I also use a 16:16:16 designed for trees shrubs and veggies.

I have tried a wide variety of synthetic and organic fertilizers over the last 10 years, i had a fertilizer collection...

I eventually gravitated towards using an even N:P:K ratio and supplementing N.

i focus on both health and growth rate.

I used to use worm castings, blood meal, bone meal, feather meal, alfalfa meal, compost tea, manure tea, cotton seed meal, compost top dressing and other stuff like that

but i really don't care for the organic fertilizers anymore

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Is biochar just charcoal from wood as you could find after a bushfire? How much should you add to existing soil? And why is rockdust so popular, is it literally rock crushed to dust that contains lots of minerals?

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The best results I've seen are those of a commercial grower who uses vegetable based compost as part of his soil mix and waters with EM (Effective Microorganisms). He does not fertilize and does not use a rich mix yet grows 4-6" in diameter columnar trichs and has them flowering in 5 gallon pots. The stuff eats coir so the soil level drops.

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rock dust is avail everywhere in W.A.

10kg for $30 RRP where I am.

There's a new product I am yet to fully investigate, but it contains liquid carbon, meant to be the bomb, or so the sales rep said :P

I like the new pelletized ferts that are comming out with NAASA and BFA certification, the generally contain poultry manure, blood and bone, fish meal, seaweed, rock dust, suphate of potash, natural gypsum, worm castings and maybe 1 or 2 other ingredients I have forgotten all in one convenient pelletized form.

PS, lab testing of Oz's best known pelletized poultry manure has shown disturbingly high levels of Pb, Hg and Cd :( not meantioning any names DL from Y***s.

I also want to find out where these places source there chicken manure from, I doubt there's enough free range poop to supply it all and collecting it would be hard as opposed to intensively farmed chickens who are wading through their own excrement by the time the 6-8 week growing period is over. If that's where these polaces source there poop from, then I don't think they deserve organic certification.

Edited by naja naja

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