Yellowing Cacti

[Rum and Monkeys]

Hey gang,

I pretty much have only been using Charlie Carp last growing season as fertiliser and now I have noticed 80% of them are turning rather yellow..

A: what are my cacti lacking

and, B: what fertiliser should I use to compensate for lacking nutrients?

taa

[Evil Genius]

Nitrogen!

[Leaves]

Some of the faster growing ones when in pots I just feed them as I would any pot plant during summer. I was surprised how vigorous some species can be ie trichocereus.

[gtarman]

Nitrogen!

But if he was using Charlie Carp/fish emulsion, shouldn't that have had plenty of Nitrogen in it?

[Sallubrious]

But if he was using Charlie Carp/fish emulsion, shouldn't that have had plenty of Nitrogen in it?

It should have but it doesn't mean that it is available to the plants. Things like soil PH can have an impact on nutrient availability.

I don't know if they are potted plants or in the soil, but feeding potted plants with fish based ferts can cause the soil mix to become repellent because of the oils and proteins in the fertiliser. If the soil mix is repellent then the nutrients and water won't be getting to the plants, so that can cause deficiency symptoms. It's a big problem with plants like cactus that need a good dry cycle, they can be very difficult to re-wet and most of the water just runs down the side of the pot and out the bottom.

I'd do some investigation on at least one yellowed plant to see if there are any root zone problems such as root mealies or repellent soil ect. A good soak in a bucket with water and possibly some soil wetter or a squirt of dishwashing liquid (detergent contains wetting agents) should help water to get into the soil mix if that is the problem.

Charlie carp is OK as long as the soil is soaking it up, it wouldn't be my first choice for a cactus though. I'd only use it in conjunction with regular treatments of wetting agent.

Miracle grow is good for cactus, if you can find the one with balanced NPK, the older stuff (which many places still stock) is 15 N, 13.1 P, 12.4 K works well for cactus, the newer one is low phosphate and way too much nitrogen for most plants. Most ferts have gone this way due to issues with runoff causing algal blooms. I don't know if it's because of legislation but it is becoming difficult to find a good balanced ferts these days. Miracle grow has a wetting agent too.

I never thought I'd give chemical ferts a plug but organic ferts have caused me a lot of problems involving repellent soil. I only use it on potted plants though, cactus in the garden will grow on almost anything without problems.

Edited August 17, 2013 by SallyD

[Rum and Monkeys]

It should have but it doesn't mean that it is available to the plants. Things like soil PH can have an impact on nutrient availability.

I don't know if they are potted plants or in the soil, but feeding potted plants with fish based ferts can cause the soil mix to become repellent because of the oils and proteins in the fertiliser. If the soil mix is repellent then the nutrients and water won't be getting to the plants, so that can cause deficiency symptoms. It's a big problem with plants like cactus that need a good dry cycle, they can be very difficult to re-wet and most of the water just runs down the side of the pot and out the bottom.

I'd do some investigation on at least one yellowed plant to see if there are any root zone problems such as root mealies or repellent soil ect. A good soak in a bucket with water and possibly some soil wetter or a squirt of dishwashing liquid (detergent contains wetting agents) should help water to get into the soil mix if that is the problem.

Charlie carp is OK as long as the soil is soaking it up, it wouldn't be my first choice for a cactus though. I'd only use it in conjunction with regular treatments of wetting agent.

Miracle grow is good for cactus, if you can find the one with balanced NPK, the older stuff (which many places still stock) is 15 N, 13.1 P, 12.4 K works well for cactus, the newer one is low phosphate and way too much nitrogen for most plants. Most ferts have gone this way due to issues with runoff causing algal blooms. I don't know if it's because of legislation but it is becoming difficult to find a good balanced ferts these days. Miracle grow has a wetting agent too.

I never thought I'd give chemical ferts a plug but organic ferts have caused me a lot of problems involving repellent soil. I only use it on potted plants though, cactus in the garden will grow on almost anything without problems.

These are potted plants, and some have been potted up for a long period of time, so maybe the soil is acting 'repellent' to the water/ferts. They have been neglected lately, and have really no dry time because they are outdoors and it almost rains all year here..

So sounds like a I need a wetting agent, plus a different fertiliser?

[Sallubrious]

If it rains as much as you say it could be the opposite to what I stated above, the plants could just be getting all their nitrogen/nutrients washed out. I'd think that you could be having problems with rot if that were the case though

You really need to do some investigation into the conditions around the root zone and try to provide the growing conditions they require.

Also cactus need a dark period to function, as they rely on an adapted photosynthesis system known as Crassulacean Acid Metabolism. If they have a strong light shining on them they won't be able to efficiently exchange gases & make the sugars needed to feed themselves no matter how good their nutrition is.

[gtarman]

I don't know if they are potted plants or in the soil, but feeding potted plants with fish based ferts can cause the soil mix to become repellent because of the oils and proteins in the fertiliser. If the soil mix is repellent then the nutrients and water won't be getting to the plants, so that can cause deficiency symptoms. It's a big problem with plants like cactus that need a good dry cycle, they can be very difficult to re-wet and most of the water just runs down the side of the pot and out the bottom.

I'd be interested in finding out more about this - it could be a matter of correlation vs. causation...I've been using fish-based ferts on some potted plants but not on others for a little while now, and they still wet and dry at the same rate.

I think it's probably just because if you let any commercial potting mix dry out, it tends to become hydrophobic and hard to re-wet. With most plants you just tend not to notice it as much as with cacti because we tend not to let them dry out as thoroughly (if at all), or on purpose.

But it could be a thing I guess...I just couldn't find any info regarding the problem on the interwebs

[zelly]

for cactus soil conditions & everything else, read this pdf

http://xerophilia.ro/wp-content/uploads/2013/08/The-Stone-Eaters.pdf

[gtarman]

^ will have a gander tomorrow. That's a massive pdf!

Oh and also. @Rum and Monkeys: it could be a moisture thing, as SallyD was saying - if it rains all year where you are. Depending on species, some cacti enjoy heavy watering - but only in the growing season. But the majority don't enjoy large amounts of water, especially not year round.

I'd say the reason they're turning yellow now, is because during the growing season they were just wet - but now they're cold and wet, a very bad combo for cacti. When it's cold, they need to be dry.

Edited August 17, 2013 by gtarman

[Leaves]

Does anyone see any problem with me using Dynamic Lifter & fresh worm juice on my succulents/cactus? I have used it in the past during spring/summer and they seem to grow and flower well, but I was worried I could give them some disease or something from the bacteria in the dynamic lifter/worm juice.

[Optimystic]

I used fish emulsions once and didn't feel right about it... it burned the tip off a barely rooted bridge but everything else was okay

but what i was using before was botanicare pro grow in low doses ... I think its got bat guano, kelp and some other stuff,,, I use a little kelp in my water often too but I think some products have too much saline so im using freshwater dry soluble kelp.. I was normally using botanicare for indoors like for pereskies cause it smells nice or at least is not foul smellling.. but its also a bit pricier.. I was really surprised when the first trichofarmer mentioned to me that trichos eat alot of nitrogen! but yes they do!

I do put worm castings in my soil mix and I think thats absolutely great for them... not sure about worm juice but worm castings is an excellent source for nitrogen and trace minerals, but maybe theres different type of worms I dunno.. I know with bat guano, different species have different ratios of npk in their shit i.e. jamaican guano vs mexican guano

@ Zelly,,, I think that guide is an excellent resource, but not so good for finding info for Trichos imo

it has some good info about compost tho I think... one guy mentioned an echinopsis hybrid on page 99

im sure theres others but thats the only one I found so far.. i've only skimmed around and read sections tho

I have found theres a world of difference between south american wet/dry season cacti vs central and north american desert cacti

I think trichos can handle cold and wet more than alot of other cacti for sure... but the wet does keep them in growing mode

like zelly has shown before, some trichos, in some climates, they can even flower right through the winter when planted in the ground

I let some of mine get rained on early this spring, 2 days in a row and it got really cool near freezing... and well they did just fine
I was so skeert! but I had to prove to myself what other ppl were saying.... they are gonna stay outside this year but with rain protection

our winters are not very dramatic very often but they can be, but rarely do we get snow last more than a day or two , in fact we rarely get snow eh

but with the strange weather patterns this year I have no idea what to expect!

But anyways, regarding the Yellowing... are they getting any shade??? I know some trichos handle full sun alot better than others

I had an all yellow PC pach show up this year in a box... I kept it in shade and it turned green again... could be just alot of sun exposure for a plant... just to note it was the thickest PC pach i've seen and im pretty sure it came from full sun out in cali

that might prefer some afternoon shade or something and have nothing to do with nutes.. Im just throwing that out there, someone correct me if im wrong please but since this PC pach was a full sun grown specimen, I wonder if nutes would have prevented yellowing of if thats just gonna happen with some plants that don't get any shade???

Edited August 17, 2013 by Spine Collector

[Optimystic]

***Also in regards to Nitrogen, I've been planning to try some worm castings tea sometime... on another forum there was someone

who swore by it and had gorgeous plants! I haven't seen that guy around but I plan to try it out once I figure out what ratios I should be using

im not sure if thats mostly for micro nutes adn beneficials, or if the nitrogen stays in the tea but I would assume its a good source for natural nitrogen

does anyone use worm castings tea???

If the yellowing problem is an issue with nutes, I wonder how that might help

Edited August 17, 2013 by Spine Collector

[Bigred]

Try flushing the soil with a solution of magnesium sulphate and using charlie carp will cause

the ph to lower a bit but not much .So check the PH but my recommendation would be to use

a slow release fertiliser and give it some mag sulphate

[zelly]

people that grow cactus plants in pots have a far different row to hoe than people who grow their cactus plants in mother earth and distinctions between the two methods need to be made & understood.

regarding trichocereus in natural habitats, dont other cactus & succulent species happily coexist & flourish?

who comes along every six months or every sixteen years & fertilizes them?

I just have a hard time believing trichos need 'something special or different' whether grown in a pot or in mother earth.

How do saguaro's get so big without any man made fertilizer?

IMHO, the real travesty is 'human intervention' of forcing abnormal growth rates to satisfy 'human needs & demands' on a natural plant growth cycle.

[Sallubrious]

Thanks for the link to that PDF Zelly, it was a good read and it certainly makes a lot of sense. The author has very good observational skills and has applied them to his system very well. I instinctively knew that the commercial cactus mixes contained way too much compost and have mixed in a lot of rock/gravel to help get it to a decent mix. After reading that I'll modify my mix a lot more and accept slower growing plants that will most likely be tougher and flower a lot better.

people that grow cactus plants in pots have a far different row to hoe than people who grow their cactus plants in mother earth and distinctions between the two methods need to be made & understood.

regarding trichocereus in natural habitats, dont other cactus & succulent species happily coexist & flourish?

who comes along every six months or every sixteen years & fertilizes them?

I just have a hard time believing trichos need 'something special or different' whether grown in a pot or in mother earth.

How do saguaro's get so big without any man made fertilizer?

IMHO, the real travesty is 'human intervention' of forcing abnormal growth rates to satisfy 'human needs & demands' on a natural plant growth cycle.

I believe that potted plants need different nutrients to their soil grown counterparts. Plants grown in pots are isolated from the natural nutrient and hydrologic cycles which soil grown plants benefit from. A large plant like a Trich can get all it needs from most soils due to unlimited root space and nutrient cycling where a pot bound specimen can deplete nutrients from a small pot full of soil mix as it accumulates biomass, the tissue has to come from somewhere and it's the elements in the soil that supply them.

Adding fertilisers is our feeble way of trying to replicate and replace nutrients that soil grown plants get naturally, but as you suggested in your last sentence Humans think they can do it better than nature so most times we use way too much and all the wrong ratios of elements.

[J Smith]

I've used Charlie carp and thrive for the last couple of years. I got a worm farm about 9 months ago so will probably use only worm juice as fert once I finish off the rest of the Charlie carp this summer. Never made a yellow cactus but I've recovered a few by repotting then into good quality potting mix.

[.dg]

didn't read the whole thread- but

too much sun?

if you are feeding them at all i doubt its nutrient related

pics?

[Rum and Monkeys]

to

But anyways, regarding the Yellowing... are they getting any shade??? I know some trichos handle full sun alot better than others

I had an all yellow PC pach show up this year in a box... I kept it in shade and it turned green again... could be just alot of sun exposure for a plant... just to note it was the thickest PC pach i've seen and im pretty sure it came from full sun out in cali

That may be it, they get the first sun in the yard and have no shade until the sun pretty much goes down.. Maybe it's time to move them to a different corner. I moved them to the place they are now because I could not fit them all undercover and thought that with the cold wintery weather, that more direct light would be better for them, rather then a cold shaded area for winter..

Mind you, they probably all need repotting in some new soil as well.

Thanks for everyones input, it's very interesting read

[Rum and Monkeys]

I will take some photo's today, some are really yellow some are not so much... Seems to affect the smaller cacti worse then the bigger ones.

While i'm taking photo's I will upload one or two of a weird black spot that is appearing around some of the Trich's. Dosen't look fungal or deadly though.. Photo's will explain better then me.

Won't be long