What to feed my cacti

MickAfrica · Post by **MickAfrica** » Tue Jan 31, 2012 8:04 am

Living off the beaten track makes it difficult to find the right thing. I have got a product called Seagrow - an organic plant food. Is this OK for use on cacti?
Mick

peterb · Post by **peterb** » Tue Jan 31, 2012 1:58 pm

does it have NPK numbers? Regular feedings in strong light and during growing season should still be low nitrogen. I use 20-20-20 and dilute it significantly. Most cactus food is 2-2-7 or in that range.

peterb

Arjen · Post by **Arjen** » Wed Feb 01, 2012 7:17 am

sorry for the hijack but would 3-1-5 be alright too?

Peterthecactusguy · Post by **Peterthecactusguy** » Wed Feb 01, 2012 11:22 am

the stuff I use is 2-2-7. It seems to work ok.. I dilute it a little too...

iann · Post by **iann** » Wed Feb 01, 2012 2:36 pm

Anything is OK for a while, especially if you keep it dilute. Too much nitrogen at once is a problem that can be partly counteracted by sufficient quantities of the other nutrients. 3-1-5 might have too little Phosphorus for some longterm use. Look for something balanced or with the first number smallest, although you can usefully apply a straight nitrogen fertiliser at very low concentrations. Nitrogen doesn't persist in the soil while the other nutrients can be stockpiled for many months.

Look for a fertiliser with trace elements, especially if you are growing in "sterile" media such as peat and perlite. Loams and natural rock products provide some trace elements but it still makes sense to top them up with a fertiliser because it is likely that some are in short supply.

My final advice, almost always ignored, is to learn what ppm means

Arjen · Post by **Arjen** » Thu Feb 02, 2012 7:31 am

I'll break the 'ban', what does it mean?

hob · Post by **hob** » Thu Feb 02, 2012 8:39 am

parts per million

majcka · Post by **majcka** » Thu Feb 02, 2012 10:41 am

hob wrote:parts per million

Now when you mention it looks logical.

Peterthecactusguy · Post by **Peterthecactusguy** » Thu Feb 02, 2012 12:13 pm

basically parts per million is a measurement. (for liquid solutions)

iann · Post by **iann** » Thu Feb 02, 2012 7:11 pm

ppm measures what you actually put on the plants. If you put 2-7-7 on without diluting it you would kill them, so it is pretty pointless to say you use 2-7-7 without saying how much you dilute it. Also pretty pointless to say you use 7-7-7 instead of 20-20-20 since they will both be the same by the time you put them on the plants.

Rather than give two or three different bits of information and expect people to work it out for themselves, just give the ppm and everyone knows exactly what it means. Except they don't because people have been conditioned since birth to think that numbers are hard

Peterthecactusguy · Post by **Peterthecactusguy** » Thu Feb 02, 2012 10:31 pm

Ian,
well I do say I dilute mine. I follow the instructions and DILUTE it further.

BTW I hate numbers. I am not good at math. So people like me are part of the problem

iann · Post by **iann** » Thu Feb 02, 2012 11:05 pm

Peterthecactusguy wrote:Ian,
well I do say I dilute mine. I follow the instructions and DILUTE it further.

That's my whole point. You have no clue what concentration you are actually putting on your plants, so I have no clue, so I have no idea if you are fertilising more or less than I am. Which one of us should change because the other grows better plants? No idea.

You wouldn't tell someone that you "water your plants quite often and so should they". You know that means nothing to nobody and you'd never do it (I hope!), yet people are always giving advice about fertiliser that is just as useless.

MickAfrica · Post by **MickAfrica** » Fri Feb 03, 2012 7:15 am

Have read all the posts, and must say am a little more confused than I was. The Seagro organic stuff I have reads per kilogram N - 53, P - 7 and K - 17. The dilution is 5ml to a litre of water, so guess if I dilute more it should be OK.
Getting hooked on these prickly pals.
Mick

Arjen · Post by **Arjen** » Fri Feb 03, 2012 7:48 am

well from what I've understood so far that N-number is way too high

Post by **Steve Johnson** » Fri Feb 03, 2012 4:55 pm

Peterthecactusguy wrote:Ian,
well I do say I dilute mine. I follow the instructions and DILUTE it further.

BTW I hate numbers. I am not good at math. So people like me are part of the problem

I am good with numbers, but not the proper terminology when I'm unfamiliar with a given application. Let's say for example, I have a certain liquid fertilizer which I dilute by putting a teaspoon into a gallon of water. I have no idea what the PPM numbers are, but if I talk about fertilizer N-P-K and dilution rate, that I can understand. Would this be useful to know if a given fertilizer is doing the right thing or not? I totally agree with what Ian is saying, so without some context any discussion of fertilizers is meaningless. (I have no problem with math -- if someone can give me the basic formula for determining PPM by volume, I can do the math.)

By the way, I'll add another wrinkle to this. Basically it's about taking a look at the particular species of cacti being cultivated in one's collection. I don't want to hijack this thread any more than I already have, but food for thought about considering the cacti people actually have as opposed to a "one size fits all" approach that could send incomplete advice in the wrong direction. I'd hate to see anyone ending up killing their cacti due to lack of knowledge on proper cultivation methods. (Sorry, but I have a feeling this happens waaaay too often.)

What to feed my cacti

What to feed my cacti

Thanks for feedbacks