Melocatus help

[Salazar]

A few days ago I bought a melocatus, not entirely sure about species though, I was wondering how to go about growing it since it's my first time and this plant wasn't cheap and almost impossible to find in my country I want to know how to grow it best.

I live in the Philippines and I do know melocati come from the tropics but all the information I've found in cultivating them have come from growers in temperate regions. I would like some growing tips from someone growing them or who have grown in the tropics.

Thanks.

[Steve Johnson]

A few days ago I bought a melocatus, not entirely sure about species though, I was wondering how to go about growing it since it's my first time and this plant wasn't cheap and almost impossible to find in my country I want to know how to grow it best.

I live in the Philippines and I do know melocati come from the tropics but all the information I've found in cultivating them have come from growers in temperate regions. I would like some growing tips from someone growing them or who have grown in the tropics.

You're lucky to be living in a place where Melocactus will grow year-round, so you won't have to deal with the over-wintering problem common to most of us keeping Melos in our collections. However, there are 2 things for you to consider. First, they have shallow root systems, so a squat pot is best. If your Melo already has a cephalium, then the green part of the plant is as wide as it'll get. Add about 1-1.5" (2.5-4 cm.) to the diameter of the base, and that'll give you the inside diameter of the pot. Depth should be less than diameter -- for example I have a Melo matanzanus in a 4" x 3" pot, which is pretty much perfect. If your Melo is still in the juvenile stage, it won't be as finicky about pot size yet.

I live in a fairly humid coastal microclimate, and this allows me to go very lean on the mixes I use (in other words, little or no soil). For my soil-less cacti, it's a 60/40 pumice-granite gravel mix. For the Melo matanzanus, I add about 20% soil to the mix. I believe that your climate is even more humid than mine, so if you have easy access to horticultural pumice, you may not need anything else. Be sure to clean the roots thoroughly before you repot your Melo. Let it settle in for a week or two, then water it every 7-10 days.

[Salazar]

I've just repotted it yesterday, my soil has much more organic matter than what you recommend,around 40%-50%, I also used some coco coir is this fine?

Should I unpot it and add more inorganic components?

I have access to pumice for free but here the pumice comes from construction sites where the concrete mix is sifted on site and what they sift out is unwanted pumice and I collect it, would this kind of pumice be fine?

[Salazar]

Also the humidity almost never gets anywhere below 70% and at this time of year it's about 80% daily.

Should I go for a soil-less mix and just add some slow release fertilizer?

[Steve Johnson]

Stay tuned for a response from me later today -- I think you may find it interesting.

[jp29]

Please refer to the "Let's grow some Melocactus!" thread above -- especially the first page.

[Steve Johnson]

I've just repotted it yesterday, my soil has much more organic matter than what you recommend,around 40%-50%, I also used some coco coir is this fine?

Should I unpot it and add more inorganic components?

I have access to pumice for free but here the pumice comes from construction sites where the concrete mix is sifted on site and what they sift out is unwanted pumice and I collect it, would this kind of pumice be fine?

Although it may seem counterintuitive to "old school" methods of cactus growing, Melos do much better over the long run if they're being grown in a lean mix with a minimal amount of organic materials. In theory, sandy loam as the soil component would be ideal, although in practice it's difficult to find anything that isn't loaded with organics. I don't use coir, but reliable sources tell me that it's close to being nonorganic and therefore less prone to setting up the conditions for rot as we'd see with other organic materials. Roughly speaking, the humidity in my area fluctuates between 50% and 80-85%, so the soil I added for the Melo matanzanus is to make sure that the mix doesn't dry out completely between waterings. If the RH in your area is more consistently high (say 70-80%), you may be able to go completely soil-less. With that said, your country is pretty dang hot, so I'm not sure if high humidity works for or against the idea of a soil-less approach. If you're not sure, I think you'd be fine with a 4-to-1 mineral/soil ratio, where coir acts as the soil component to maintain acceptable moisture retention in the mix. Now we'll look at 3 other issues.

Pumice -- here's a digital photo of my pumice-granite gravel mix with a handy-dandy scale for reference:



If the grain size range of the pumice you get is about the same, you're set. Just be sure to rinse it thoroughly in running water and let it dry out before you start using it.

Fertilizer -- I fertilize all of my cacti pretty much every time I water. My fert of Choice is Dyna-Gro All-Pro 7-7-7, diluted at a rate of 1/2 tsp. per gallon of water. Here's its nutrient profile (and the reason why I won't use anything else):



Downside to the 7-7-7 is that it comes only by the gallon, which makes it kinda expensive. Dyna-Gro also offers a 7-9-5 in different quantities, with the same profile of minor and micronutrients. This may be a more affordable option for you, so try Amazon or eBay.

Water quality -- the minerals in hard water have negative consequences for the long-term health of our plants. The tapwater here in L.A. is hard, so I acidify it with white vinegar. If you can store a sufficient supply of rainwater, simply water your plants with it, and you won't have to worry about the hardness problem.

James has been growing Melos a lot longer than I have, so his advice is definitely worth considering. After reviewing his first post in "Let's grow some Melocactus!", I'll revise my comment about proper pot depth for the roots. Other than that, his approach seems to be remarkably similar to mine. If you post a photo of the Melo, it would be nice if we can see what you have.

[jp29]

Actually over the years I have found that substrate constituency -- mostly the amount (or absence) of organic material -- doesn't appear to have that great an effect on the vigor or vitality of Melocactus growth. Check the large, old, specimens I illustrate that were mostly grown in a 60% pumice/40% composted forest mulch soil mix (some in very humid Florida) and which have flourished for many years.

What I have found is that my plants are easier to water and maintain in mostly mineral substrates. Check out especially my "Cultivating cacti semi-hydroponically" web page: http://jp29.org/brculthydro.htm

[Salazar]

I can't upload any photos because it keeps saying the file's too large no matter how much I edit the photo so I'll just describe the plant as best as I can.

The plant is 3 inches in diameter an 2.5 inches tall, the stem is a dark kinda bluish green color. There are 8 spines one of which is a central spine all are about 1 cm long and are a reddish orange color with a black tip when developing but turn black and as they get older the go white and when they're wet they turn red.

The soil composition is:
10% soil
10%coco coir
60% pumice
20% washed sand
A teaspoon amount of slow release fertilizer

[Salazar]

Hope this is adequate information.

[mmcavall]

Here is my experience with Melocactus: as I live in Brazil, they are “at home”, and they are very easy species to grow, even from seeds I have no problems.
I have 7 Melocactus, they are brothers, grown from seed from the same mother-plant. One of them is in the North of the country, in a friend’s house, near Amazonia, and this was the first to bloom (the others didn’t bloomed yet).
The other 6 plants were in my mother’s house. When I finally built my greenhouse I bring 3 of them with me, so 3 are with my mother, and 3 are with me.
The interesting thing is that those that are with me are in more draining mixes, clay pots, full sun and they are fine, BUT, those that are with my mother are in plastic pots, partially shaded and in a very poor draining mix, almost pure top soil. So which looks better? Those with my mother. Every time I visit her I get surprised with the Melos, in a very humid place, partially shaded, wet soil, and looking much better than mines.
One of the 3 that are with me was recently transplanted to a more draining mix, but with about 10% of leaf mold; I’ll see how it reacts.
Well, living in Brazil, at least during summer I have about the same climate as yours, very hot and wet, high atmospheric humidity (winter, however, is dry). At least, of my 7 plants, the ones from the worst conditions recommended for cacti are in fact the best looking ones. I’m not sure whether in the long term this will be inverted and they will be the weaker ones.
Not sure it helped a lot. Don’t follow my advices (did I gave one?). Or, all I can say, is that my Melos can stand in some wet, organic soil and they look better than the others Melos I’m trying to give more draining and dry conditions. Note that I dont have the ID of my Melos, and they can diferent from yours.

[Salazar]

Thanks for the replies.
Now that soil has been discussed I wan't to know how much light should they receive?
How long should they remain dry before watering again?

[Salazar]

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Finally got to post pictures!

[Salazar]

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