Restrepia leaves yellowing

[VERN-O]

My Restrepia antineffera seems to have a yellowing of the leaves issue going on. The roots have really started to take off.... Any suggestions on what might be going on and/or how to correct it?

[Ray]

How about providing some feeding details?

[VERN-O]

Originally Posted by Ray

How about providing some feeding details?

I don't fertilize very often, but recently switched to Dyna-Gro 7-9-5 (about 2/3 strength).... fertilized about 3 weeks ago...not sure if that correlates to the yellowing. The yellowing became more noticeable about a week ago. Are you thinking over fertilized???

[Ray]

Originally Posted by VERN-O

I don't fertilize very often, but recently switched to Dyna-Gro 7-9-5 (about 2/3 strength).... fertilized about 3 weeks ago...not sure if that correlates to the yellowing. The yellowing became more noticeable about a week ago. Are you thinking over fertilized???

What does "2/3 strength" mean? What water supply do you use?

[VERN-O]

Full strength would be 1 teaspoon per gallon so I would use use 2/3 of a teaspoon to a gallon on water
Water is 18megaohm deionized water

[Ray]

Originally Posted by VERN-O

Full strength would be 1 teaspoon per gallon so I would use use 2/3 of a teaspoon to a gallon on water
Water is 18megaohm deionized water

I think the issue is gross underfeeding, and possibly pH!

By using ultra-pure water, the calcium and magnesium compounds typically found in water are missing.

Dyna-Gro 7-9-5 is not bad (besides being expensive per nutrient unit), and can replace those, but I would use a full teaspoon per gallon every week.

Orchids are not particularly demanding of mineral nutrients, but should get a steady supply as while some nutrients can be transferred from old tissue to newly-growing parts, others cannot. That plant has grown a great deal, so possibly has "tapped out" the reserves.

The first thing I would do, when seeing yellowing, is water with a teaspoon/gallon of Epsom Salts. The lack of green often means a lack of chlorophyll, which usually means a lack of magnesium.

Then, after a few days, I'd rethink your feeding regimen, and start applying some regularly. I'd also check the pH of Dyna-Gro when in such an unbuffered water supply; it's probably very low.

[VERN-O]

Thanks Ray....very interesting. I was told to be careful not to over fertilize miniature/terrarium plants...so I've been cautious....I'll give it a shot...thanks for the advice

[VERN-O]

Originally Posted by Ray

I think the issue is gross underfeeding, and possibly pH!

The first thing I would do, when seeing yellowing, is water with a teaspoon/gallon of Epsom Salts. The lack of green often means a lack of chlorophyll, which usually means a lack of magnesium.

Then, after a few days, I'd rethink your feeding regimen, and start applying some regularly. I'd also check the pH of Dyna-Gro when in such an unbuffered water supply; it's probably very low.

Ray...The pH of the 18 megaohm water is 6.23
I made up a solution of the Dyna Gro and the pH is 4.13...would you consider that pH level safe to fertilize with?

[Ray]

You're right, it's easy to build up minerals in an environment that doesn't get flushed. Maybe a full teaspoon is too much, but whatever you do - 1/4 tsp/gal weekly? - apply it regularly.

Yes that pH is low, but I'll bet the substrate the plant is in will take care of that readily.

Don't forget the Epsom Salts.