The following is part of a three part series on reviving apparently dead epiphytic orchids from Volume 31 No6 July 2007
Rescuing Apparently ‘dead’ Orchids
By Brendan Killen
In late Spring 2006, I had an ‘open shade house’ event at my place in Belair, South Australia. As part of the programme, I demonstrated how I rescue orchids that have all but died. My demonstration was based on many years of experience in not giving in to the demons that cause orchids to expire.
I used two orchids that everyone attending agreed would normally be tossed into the rubbish bin or compost – all bare canes; heavily shrivelled; all new growth ‘eyes’ at the base of the canes chewed out by insects. In other words, an apparently hopeless situation. I’ve never given up on these terminal plants, believing that they still had life in the old canes along as they hadn’t turned to fermented mush.
I also used an apparently ‘dead’ cane from a treasured orchid that I was hoping would eventually produce a back-up plant using the method I describe in the following text.
In one case (Dendrobium Jayden), I cut the canes into a number of segments and stuck them into a pot with heavily compressed sphagnum moss, topped with river gravel to suppress the moss from growing and overtaking the pot. In the other two cases (Den. Alick Dockrill & Den. Sarah Jane), I cut the canes into segments and placed them in a pot of small composted bark.
The following photographs were taken about 3 months after the repotting demonstration and after the plants were relocated to Brisbane. They demonstrate the benefit of the right technique and a ‘don’t give up’ attitude. This technique has not failed me yet, allowing me to rescue many prized plants that have gone on to be show-bench winners.
PLANT #1 – Dendrobium Jayden “Jane”.
This photo illustrates the emerging new growth on a Den. Jayden “Jane”. This is the first evidence that success is at hand. It is also the first new growth discovered on this plant before I inspect the canes further to see if there are any other new growths buried within the sphagnum moss.
In this photo, you can see that the new growth is very pale from having emerged from deep in the sphagnum moss with little exposure to light. The juvenile roots can be seen emerging on the right hand side.
A closer inspection reveals another growth, on the other side. Note that both growths are not coming from the ‘eyes’ at the bottom of the canes – simply because they were cut off at potting time. They are emerging from the section that joins the cane segments.
Teasing away the sphagnum moss reveals even more of the young roots. Note how the new growths are lacking any colour substance at this stage.
If I were to ignore this plant for much longer, the new growths would have rotted in the very moist sphagnum moss, neutralising my efforts. So, the lesson here is to ensure that you monitor the plants for new growths and ensure that you elevate the new growths above the sphagnum moss to give them a chance to ‘harden off’ from their immersion deeper in the sphagnum.
This photo illustrates how I have re-seated the canes within the sphagnum moss, but much higher so that only the roots are exposed to the heavy moisture content of the moss. I choose to do this instead of placing them straight into a bark mix as I find that the plants tend to go into a shock at the relative lack of moisture in bark and can die quickly, or suffer from stunted growth. I wait until the new growths have matured with substantial green substance before I repot them in a bark mix. And, I tend to do this in late autumn when they are not under any temperature or light stress. By spring, they will be racing ahead in the bark mix with new root growth and, possibly new canes and/or flower spikes.
One Month Later……….
After one month from the re-seating described previously, note that the pale new growth is now mature and bright green. And, note how the roots are emerging from the growth above the sphagnum moss. This plant will be ready for potting-on into a bark medium in the next few weeks as autumn cools the air in Brisbane.
This is how I expect it to flower in spring
TO BE CONTINUED …..
NOSSA 