Q&A – Tight, Shrunken, Red Centers

Laurie asks Annie:

Q Hi Annie,

I have had this problem for a while now. The crown leaves get really small and hard. I have had concerns of cyclamen mites, then ‘culture’ break. Recently I remembered that I had read somewhere that if the soil dries out to water with plain water and then use a fertilizer the next time?

Thank you for any help…

Laurie's plant with a tight, brittle center that is showing some pink in the leaves.
Laurie’s plant with a tight, brittle center that is showing some pink in the leaves.

A Hi Laurie!

My first thought was mites, but upon a closer look, I did not see any of the telltale grey webbing. Even so, I suggested that you isolate the plant. I wondered if you might have a fertilizer buildup, but this was so unusual that I checked with Joyce. Here is what she said:

That’s very unusual. I would agree that it isn’t typical of Cyclamen mites. The leaves don’t appear to be dying. I’m seeing a pigment change in the small center leaves which I think relates to nutrition or cold temperature. I’d like to know what the root pH is, what fertilizer and what water she uses, and what the air temperature is where the affected plants sit. 

Joyce

We had additional conversation and Laurie responded to Joyce’s questions:

Soil:
I don’t have a meter to check soil, only can measure the runoff. My potting mixture is purchased from Selective Gardener and I add approximately 5 parts their mix with 4 parts perlite and 3 parts vermiculite.

Water:
My tap water is pH 8.0 and until I remembered/realized it was that high my plants just weren’t growing. When I adjusted it with white vinegar to around 6.0 my plants flourished. I was guilty of not repotting in a timely manner but have been repotting, here and there, healthy plants and then this problem has happened.

Lights:
I have three shelves with one ballast per shelf that holds two T12 bulbs, one warm and one cool. I ran them about 10 hours during winter and a few weeks ago upped to 12 hours. The plants are blooming on the healthy plants and a few that aren’t 100%.

Temperature and Humidity:
I have kept them under a domed tray – not all until several months ago – for fear of bugs as I did find thrips about 1 1/2 years ago and eliminated manually. We keep our house at 68˚.  I did check temp about two years ago and the top shelf was about 75˚.  In the summer I don’t open the window because of pests – I have seen thrips in my garden which is side of house the window faces, room is south facing on second floor. I close the shades on a sunny day.

Laurie went on to say that she didn’t remember which plant she shared, but that she had seen a redness in some crown leaves of a few plants.

As usual, Joyce had a pretty good theory. Here is her response:

I think the fact that she is maintaining 68 degrees might explain the red color. There is often a change in color for many plants when temperatures are cooler (think how plants change in autumn) that brings up a reddish or purplish color in the leaves. It’s the result of plant chemistry that I don’t fully understand, but certain plants and cultivars are more inclined to do it than others. We see it mostly in the stems and on the backside of the leaves in African violets grown in cool temperatures (along with deeper flower color.)

Because it is a chemical reaction, the pH, the potting mix, and the fertilizer would all play a role in how exaggerated the color change would be.

That cool temperature would also account for the tighter growth pattern, since there is slow cell division below 70. If the hybrid were developed in a warmer climate, it wouldn’t be surprising that this particular plant grew differently in a colder climate – although this particular reaction is new to me.

I think we suggested that it remain isolated – but I’d also suggest now that she move the plant to a higher shelf or warmer spot to see if the growth pattern changes. That would be the best way to prove my theory correct (and it is only a theory.)

Joyce

Laurie, I hope this helps!


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