dead roots - Orchid Board

Katrina33 · #1 02-22-2019, 01:18 PM

I have several orchids which suffered over watering and their roots are all dead except for a very few fairly healthy air roots. Should I cut off the dead roots and repot with those air roots buried in medium?

cluelessmidwesterner · #2 02-22-2019, 01:56 PM

Beging new to orchids myself and having had a Phal lose all its roots I can identify with your problem.

First of all, don't cut anything until you hear from some of the more experienced growers. You can't put back on what you've already cut off.

Second Please post (if possible) some photos. Those will give folks a better idea on how to assist you.

Having said the above, when (and if) they tell you to cut off dead root, afterwards set the orchid somewhere to allow them to dry bare rooted for a day. A day drying out won't hurt them.

You maybe told after the drying out period just to soak the roots for a certain amount of time and then put the orchids up to dry still bare rooted for so many hours. You may have to do this for a few weeks to 1. re-hydrate the orchids and 2. give them a chance to grow some new roots. You may have to spag and bag the orchids but that depends on your environment (how dry the air in your home is) and how dehydrated your orchids are.

When you have some new roots, pot your orchid up in a pot **only** large enough to hold the roots the orchids have and no more. Do not pot it for the size of the top of the plant (I learned that one the hard way). So for a long while you will orchids with huge leaves in a teeny tiny pots. Then only water when the media is dry (repeating the wet/dry cycle). There's a sticky that describes how to tell if your orchid needs water.

Hope this helps

Katrina33 · #3 02-22-2019, 02:53 PM

Thanks so much for the advice. I am also glad you told
me about the pot size!

aliceinwl · #4 02-23-2019, 02:35 AM

What kind of orchids do you have? I’m assuming Phalaenopsis? What kind of media were you growing in and under what conditions (lighting, temperature, pot size/type)? What are you planning to repot them into? Pictures would help too.

Katrina33 · #5 02-23-2019, 11:24 AM

Actually I have two cattleyas, one phal, and one dendrobium. I've had them for 4-5 years and the cattleyas have bloomed twice a year religiously, the phal once, and the dendrobium once yearly. I have them in my south-facing kitchen window. (in Columbia, SC)
I got troubled by how big they were growing and made the mistake of repotting them and that's when the trouble began. I took a noted orchid expert's advice and used a mixture of coconut husks, perlite, and horticultural charcoal. After several weeks, the roots were turning black and becoming mushy. There were plenty of healthy air roots but the ones underneath were
dead.
I then thought maybe the charcoal was at fault. I took them out of the mixture, repotted in just coconut and perlite. None of them have bounced back but the dendrobium. It had several live roots which were actually in the medium and they took better root. It's now blooming. The others have put out a few new shoots but no really healthy roots under the plants and the air roots are beginning to dry out.

Ill try to figure out how to post a photo. I'm a clutz at that.

estación seca · #6 02-23-2019, 12:11 PM

People commonly use mixtures containing any or all of bark, perlite, coconut husk chips (CHC) and charcoal. I don't think that was the problem.

When did you repot these plants? Phals can be repotted at any time conditions are warm. They can continue root growth all year. Not so Cattleyas, nor many Dendrobiums. These produce new roots only during certain times each year. Especially in Cattleyas, this can be a relatively short period of new growth, maybe only a few weeks, once per year.

Older roots on Catts and Dens probably don't work that well. Repotting generally damages roots to some degree. This means a Catt repotted at the wrong time of year may struggle for months with a damaged root system before it grows new roots and recovers its health. Also, most Catts, and many Dens, should be watered much less through cool winters.

The time to repot orchids is when new root growth is just beginning.

aliceinwl · #7 02-24-2019, 12:47 PM

Now that you have 5 posts, I think you can post directly. I wouldn’t cut anything. The dead roots may be able to still wick in some moisture and will help keep the plants stable. I have some charcoal in pretty much all my mixes so I don’t think that’s the problem.

I wonder if you repotted larger and the center ended up staying too moist? If you suspect this might be the case, I’ve seen others suggest a good sized rock in the center of the large pot or a smaller inverted pot. You can also use the skewer method in the sticky above to see if you have issues with a wet center.

Any movement can damage new root tips once they start to grow, so I’d suggest staking the plants if there’s any wobble. If you have a coarse mix and can bury the air roots without burying the plant this is a possibility, but you have to be pretty sure you’ve narrowed down what killed the original roots. Alternatively, I’ve had good luck giving air roots a heavy daily misting until my plants could send new roots into the media.

Katrina33 · #8 02-24-2019, 01:19 PM

Thanks. Yes, I went slightly larger and I think that the center being moist could have been the issue. The roots that were the worst were in the center. I also will mist the air roots.

I am also thinking the advice about when to repot helps. I am afraid I may have repotted just as the cattleyas were putting out shoots which was the exact wrong time to do that. Drat! Live and learn.
They are now putting out shoots even with the pathetic root system!

estación seca · #9 02-24-2019, 11:30 PM

Some Cattleya species and hybrids make shoots first, then roots. If you repot and damage the old roots the plant suffers until (if) it makes new roots. Sometimes people repot at the first sign of shoot growth, but this is not a good idea.