If a tree needs potassium...

[Mike Corazzi]

Could you crush a potassium supplement tablet and dissove it in water and use it? I hear that besides iron, a pale green indicates a potassium need.

 

[0soyoung]

Just give it a banana

If you apply a fertilizer that has NPK all non-zero numbers, it should already have plenty of K.

 

[Mike Corazzi]

Just give it a banana

If you apply a fertilizer that has NPK all non-zero numbers, it should already have plenty of K.

Put the banana in a bowl of Special-K ?

 

[Maloghurst]

Put the banana in a bowl of Special-K ?

Yes then give your tree a golden shower.

 

[Forsoothe!]

50 years ago when I first started serious gardening I began a list of necessary micro-nutrients as I read about this or that problem. When the list passed 35, I gave up. Plants need a tiny amount of almost everything under the sun, including arsenic and lead and other toxic elements as or in compounds with basic elements of C, H, & O, and, almost everything could be present in amounts too much for plants too, so without testing for this or that being too little or too much, it's a crap shoot. Too much, or rather too available, is not much better than too little. Your plant might have a mass of a pound or five pounds or whatever, and that one tablet that may be just fine for a 150 pound human that processes K really fast or really slow or pick your variable, might be exactly what your plant doesn't need. Or, not. You always need to keep in mind that it's not the elemental form of the mineral that is important, it's the availability of the element, and that usually means as a component in a compound of other elements. Most good liquid fert formulae have all or most of the most common micro elements necessary in the proper proportions and they're idiot-proof if label directions are followed. And they don't smell like two-week-old bananas, either.

 

[Leo in N E Illinois]

Pale green can be low potassium. Excess potassium yields stalled growth, an off color green, more toward olive green, and hard red edges to leaves. All Potassium salts is very soluble in water, it is difficult to end up with excess Potassium except in greenhouse or hydroponic situations where fertilizer is applied continuously.

Just use a commercial fertilizer. Regulations requires fertilizer labels to list in order Nitrogen, Phosphorous, Potassium. The NPK. K is the symbol for Potassium.

Potassium is needed in many phases of metabolism. Interestingly, potassium is required in equal amounts to the Nitrate Nitrogen. Nitrogen can be in the form of Nitrate, Urea, Ammoniacal, or as Amino Acids. All forms are absorbed by plants. But for a plant to absorb Nitrate, active metabolism is required, and it also requires the use of Potassium. This is why most nitrate based fertilizers have the K number equal to, or higher than the N number, for example 12 - 2 - 13.

Just buy a "standard" chemical fertilizer, like Dynagro, or Peters, that includes potassium. It is far easier than trying to dose all the nutrients separately.

The human potassium supplement is usually potassium chloride. The potassium part would be no problem, but the chloride part may well exceed the plants tolerance for chloride. Salt as in sodium chloride, or potassium chloride can be rough on a plant. Too much will cause problems. Usually potassium in fertilizers is in the form of nitrates, or phosphates. When a commercial fertilizer adds potassium as potassium chloride, they are conscious of the limits that plant normally would tolerate of chloride.

 

[Adair M]

I don’t understand a lot of people’s attempts to “reinvent the wheel” when doing bonsai.

 

[Mike Corazzi]

To clarify, I wasn't thinking of a "pill per tree." For one thing, it's hard to get trees to "open wide and take this."
Especially the small leafed ones.
I was considering crushing a pill in water and using that.

 

[AlainK]

Something I read in an old magazine, an article translated from Japanese. It was an article about a bonsaika who would burn Zelkova leaves in autumn, then dilute the ashes in water, filter it and use it as a fertilizer when repotting. Potassium is good for the roots

Online translation from a webpage in French :

Wood ash is made up of lime for 20 to 50%, which makes it a fertilizer rich in limestone, that is to say in calcium. It contains between 3 and 9% potassium, so a concentrated fertilizer, 14% silica, up to 4% magnesium, a major constituent of plant chlorophyll, and less than 2% phosphorus.

However, one should not spread too much wood ash on the grounds at the risk of destabilizing their chemical balance because of an excess of potash and calcium.

So it's better when your soil/water is acidic (pH<7)

 

[Leo in N E Illinois]

Could you crush a potassium supplement tablet and dissove it in water and use it? I hear that besides iron, a pale green indicates a potassium need.

Second reply from me. Pale green can also be just not enough nutrition in general. Low nitrogen can leave a tree pale.

What is your "normal" fertilizing practice? Are you using a commercial fertilizer? Are you one of the "organics only" crowd? What do you normally do?

If you share your normal fertilizer program, we can tell you what needs to be tweaked. Chemical fertilizers work, all organics works. Each has their own nuances.

If you are doing zero fertilizer, it is time to start.

There are a number of well balanced products that work well as fertilizer.

 

[Mike Corazzi]

I use both a light blue Miracle Gro and an organic.
ONLY the boxwood is pale.

 

[parhamr]

Don’t forget that plants can only access nutrients when the pH is within the “correct” range. It’ll vary by nutrient and plant, but when considering any nutrition issues, it’s always possible the plants cannot access the nutrients that are already present in sufficient quantity.

Testing the pH of your soil and water will help you understand if that’s the cause of your potassium problem.

 

[Leo in N E Illinois]

I use both a light blue Miracle Gro and an organic.
ONLY the boxwood is pale.

If you fertilize all your plants the same, and only ONE is pale - the problem is not the fertilizer. Spring is coming. There is something else wrong with the boxwood. I would look at root health. Consider repotting the boxwood. There is something going on that it is not absorbing nutrients the same as the other trees you own.

 

[Schmikah]

Spring is coming.

You're going to need better house words. Not very ominous.

 

[AlainK]

If you fertilize all your plants the same, and only ONE is pale - the problem is not the fertilizer.

You mean the same plants : for different species have different requirements.

 

[Leo in N E Illinois]

You mean the same plants : for different species have different requirements.

No, I mean that "IN GENERAL" most species have fairly similar fertilizer requirements, So even in a mixed collection, if 2 dozen trees look like they are in a state of good nutrition, good leaf color, and the odd one was treated the same as the others, the odd one has a DiFFERENT Problem going on.

I don't think the color issue is really fertilizer related. Most likely there is a pest, disease or mechanical issue with the roots that has not been diagnosed yet.

Boxwood, elm, maple & juniper all need roughly the same amount of fertilizer. In fact boxwood tend to be light feeders compared to the rest. I think @Mike Corazzi has something else going wrong that is not fertilizer related with his boxwood is his other trees look good.