Brown spots on Catt leaves

[Leafmite]

I add them to all of my orchids. I water with distilled or rain water and plant everything in either red lava rock or LECA so I need to offer the plants a continuous source of calcium. Calcium is one of the big essentials for plants.
I add eggshells to all of my plants, even the low pH ones. It is a nice way to provide a slow, steady release of Calcium. Unlike with some of the other sources of Calcium, it doesn't cause me too much trouble with pH for the low pH plants.

[katrina]

Originally Posted by wintergirl

Even if it's fungal or bacteria, it could not hurt to make sure you have calcium in your media.

OF course, I use a Ca/Mg supp regularly.

BTW - eggshells need to decompose to add any actual calcium and the process is extremely slow (and some say not all that effective). I'm talking...add them to soil this summer and it won't likely be available for your tomatoes until next season. The shell needs to decompose to free up the calcium for use by the plants. VERY slow. If you just recently started adding the shells...I doubt they are the reason your plants no longer have the black spots. More likely an improvement in something else.

[Leafmite]

Originally Posted by katrina

OF course, I use a Ca/Mg supp regularly.

BTW - eggshells need to decompose to add any actual calcium and the process is extremely slow (and some say not all that effective). I'm talking...add them to soil this summer and it won't likely be available for your tomatoes until next season. The shell needs to decompose to free up the calcium for use by the plants. VERY slow. If you just recently started adding the shells...I doubt they are the reason your plants no longer have the black spots. More likely an improvement in something else.

Yes, they do need to decompose and due to this, it does take time to get the process started. However, they are quite effective for that slow, steady release of Calcium. I think it has been four or five years since I gave up the pond and had the 'Black Plague' and all I have done differently is to use the eggshells and, sometimes, if I remember, add a little powdered milk to the watering can during the summer. When I get new orchids, I add the eggshells immediately when potting the orchids into LECA or red lava rock. It is no different than adding oyster shell. :|
Yes, I know, the products you can purchase offer a quicker, more definite supply of Calcium. But, I have been doing the eggshell thing since I was a teenager and it is rather nice because it is free (and I don't need to remember to do it weekly or montly)...even if it seems a little silly. I just wish I had known when I started growing orchids that not all orchid fertilizers provide a source of Calcium. Then I would have been certain to add a source when I stopped using the Calcium-rich pond water. It was really upsetting to lose so many plants to Calcium deficiency. I found nothing about it at the time (concerning orchids) online but, thankfully, recognized it from my experience with other plants. That is why I am glad that the information is now available so that others don't go through what I did.

Yes, a great alternative to using any fertilizer or eggshells or anything else is to have a goldfish pond. My plants still miss the pond water. :|

[wintergirl]

Originally Posted by katrina

OF course, I use a Ca/Mg supp regularly.

BTW - eggshells need to decompose to add any actual calcium and the process is extremely slow (and some say not all that effective). I'm talking...add them to soil this summer and it won't likely be available for your tomatoes until next season. The shell needs to decompose to free up the calcium for use by the plants. VERY slow. If you just recently started adding the shells...I doubt they are the reason your plants no longer have the black spots. More likely an improvement in something else.

No I have been using egg shells for awhile. No other plant has gotten black spots since. I think it helps. I grind mine very small, I think they break down faster that way.

[gngrhill]

Originally Posted by Leafmite

Yes, they do need to decompose and due to this, it does take time to get the process started. However, they are quite effective for that slow, steady release of Calcium. I think it has been four or five years since I gave up the pond and had the 'Black Plague' and all I have done differently is to use the eggshells and, sometimes, if I remember, add a little powdered milk to the watering can during the summer. When I get new orchids, I add the eggshells immediately when potting the orchids into LECA or red lava rock. It is no different than adding oyster shell. :|
Yes, I know, the products you can purchase offer a quicker, more definite supply of Calcium. But, I have been doing the eggshell thing since I was a teenager and it is rather nice because it is free (and I don't need to remember to do it weekly or montly)...even if it seems a little silly. I just wish I had known when I started growing orchids that not all orchid fertilizers provide a source of Calcium. Then I would have been certain to add a source when I stopped using the Calcium-rich pond water. It was really upsetting to lose so many plants to Calcium deficiency. I found nothing about it at the time (concerning orchids) online but, thankfully, recognized it from my experience with other plants. That is why I am glad that the information is now available so that others don't go through what I did.

Yes, a great alternative to using any fertilizer or eggshells or anything else is to have a goldfish pond. My plants still miss the pond water. :|

Do you replenish the eggshells on a regular basis ? How long do you think they are good for ?

---------- Post added at 11:19 PM ---------- Previous post was at 11:13 PM ----------

Originally Posted by katrina

Looks more fungal or bacterial to me...doesn't look like Ca deficiency. I would stop misting (it doesn't do much for the plant anyway) and try to increase the air movement.



Side note...the roots look awfully dry and withered. Better, more thorough watering will help this...misting won't. This time of the year most orchids are using a lot more water since they are actively growing. I would shorten the dry time between waterings to accommodate the rapid growth that's occurring during these warmer months.

I will stop the misting. As to watering, I have always read that Catts like to get dry between watering and I am now watering them 2 times a week. I also have 2 fans running in my orchid room. One is at an open window to bring in outside air to help cool it with the T5s on and the other is just to keep the air moving. Humidity in the room runs between 50 and 60 %.

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[Cntry]

Has anyone used a small coffee grinder to crush your shells and add it into your orchids? It makes it really fine like a powder. Or do you use just chunks of shells in your pots?

[euplusia]

I agree with katrina, the damage is either of bacterial or fungal origin. To me it looks dangerous and can rapidly spread and harm the plants, so cut it off.
In my experience high humidity AND high temperatures are bad. Catts do not need misting, at least not here. You can water in the early morning or evening (on hot summer days) and provide moving air.

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[RJSquirrel]

peters excell cal+mag

15-5-10-5-2

dont need anything else, no fancy snake oils.

[Nexogen]

Because I do not trust tap water, in the last ten years we have consumed only RO water and because it is almost pure (2-8ppm) always blended it (30-45ppm) with Cal -Mag from Botanicare (cheaper and effectively than remineralizing filters).

[katrina]

Originally Posted by Leafmite

I think it has been four or five years since I gave up the pond and had the 'Black Plague' and all I have done differently is to use the eggshells and, sometimes, if I remember, add a little powdered milk to the watering can during the summer. :|

You also switched to lava and net baskets and while I'm not saying your eggshells...having been a part of your potting set up for so long...aren't adding at least a little bit of calcium. It's not impossible, I guess. What I am saying is it's more of a soil based remedy and works well there but given the openness of orchid media and set ups...it's simply not as reliable of a source.

BTW - I would bet that your new potting set up had a lot more to do w/your success in eliminating and avoiding the black rot problems. Bark + ohio's typical summer of periods of non-stop rain = lots of rot. It's why I switched to leca and lava several years ago too. It's more work when they are inside but it's necessary given the heavy periods of rain we get around here in a typical summer. Don't even get me started on the relentless rains we've had this past June...in bark I would've lost a lot more than the one I've had to pitch.

Anyway..I was just saying that if someone is experiencing a Ca deficiency (not what I'm seeing in these pics) then eggshells are not the answer to remedy the problem. Not now...maybe not even in a year of using eggshells. And if the media is so open (like lava) then there is very little media for the calcium to hold onto and be absorbed by the plants. If someone is using a denser material for potting then they might have better success with it.

My grandma used eggshells in her garden and she had an amazing garden but we're growing orchids...not in soil.

As for the cost, it's less than $20 a quart and you only need 1 tps per gallon once a month OR 1/4 tsp/gallon if you want to do it every week. It's not expensive at all. Actually, if one is buying organic, free range eggs ($4+/per dozen around here)...the eggs are more expensive.