The Coryopedilum Chronicles III - Deflasking and Potting with agar intact

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May 14, 2017
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Dallas, TX
The Coryopedilum Chronicles III – Deflasking and Potting with agar intact

This Chronicle documents the process of deflasking Paphiopedilums and potting them with the flask agar intact- or at least my own version of this practice.

I will be very frank, I am only trying this (again) because a lot of professional growers I respect enormously swear by it. I did try it once upon a time, and the plants did fine, but after a few months the remains of the agar had hardened into a thin and sticky residue that took a very long time to remove from the roots at the second compotting phase.

Looking back, there were two reasons I think I had that experience. First, the vast majority of my flasks have always come from Orchid Inn, and their agar is particularly dense. Second, when I first tested out deflasking Paphs, I had conditions that were too moist and caused a fair amount of rot. So when I tried this agar-intact method I was going through a phase in the opposite direction where I was under-watering, which delayed the decomposition of the agar.

Even so, I am attempting this with two key changes,

1. I am removing some of the excess agar where there are no roots.

2. Because I am using 4 inch azalea pots for compots, it was necessary to break each flask into two sections. Otherwise the agar would have formed a complete layer on top of the growing mix making watering and drainage impossible- to say nothing of the risks of a layer of potting mix with no air exposure from above. Switching to 5 inch pots would have been a great disruption to the efficient physical layout of my growing area (Orchid Center in Hawaii was one of my heroes in the 90s- amazing attention to space efficiency.)

And without further ado, here we go;

The hardening phase most Paphs go through out of flask can be very tricky in the first few days with the leaves sometimes actually getting limp and becoming slightly translucent for about 48-72 hours until they adjust to lower humidity conditions. Advocates of the agar-intact method have reported that they like to leave the plants sitting in open flask prior to potting to alleviate this, so I simply removed the lids from the flasks and set them under lights for about a week to get through any such shock before handling since in that weakened state even touching them can cause great damage. The rothschildianum went a little pale for a couple of days, but sprang right back- and everyone else did just fine with no adjustment shock (more on this in Chronicle IV.)

One concern I have heard expressed about leaving flasks open for several days is the growth of mold. When I first started growing orchids in the early 1980s (at age 9), this was a valid concern. My first flasking attempts were with Knudson mixes with the addition of crushed banana- and that stuff will get moldy in a heartbeat. I am not sure what is used today, but I did not have any serious issues. After a week sitting open, only one flask showed any mold at all- and even then in just one spot. Here it is, from the adductum v. anitum flask,

And now for the process- one flask of Paphiopedilum sanderianum freshly deflasked and ready to go,

Reading some various past threads on this forum, I know most of you are experts at seeing a tag and knowing who sold the flask (and probably the month and year the flask list was released), so as you can see- this is an Orchid Inn flask, as are most of the flasks in these Chronicles. So, I decided to go ahead and pull off some of the agar- taking care not to disturb the roots. I scraped gently from the bottom using the tool discussed in Chronicles II, and then I stopped at this point where I began to see root tips,

Then I very gently separated the group of flasklings into two separate clumps for compotting. To give some perspective, here is a photo of those two clumps along with all the removed agar in the center.

The rothschildianum saw a similar degree of agar removal as the sanderianum- it was a more rooted flask- but mostly with adult fuzzy roots on the top rather than extensive flask roots growing to the base of the flask. The platyphyllum were in a very easy-dissolving agar (as noted in Chronicles II), and so I did not remove any agar there.

For adductum v. anitum and randsii, I removed very little agar since there were not a lot of roots in there to hold the agar mass together if I broke it up too much (which is also a very good argument for leaving as much agar intact as possible to help stimulate slow-growing root systems.) So you can compare with sanderianum, here is a photo of the randsii flask after being broken into two clumps, with the much smaller pile of removed agar in the middle,

And finally- here is one sanderianum clump going into compot. I just set it on top of the mix and filled in around the edges (photo taken before I put the mix around the edges.) The plants are naturally growing in ideal position within the agar, so I did not attempt to put any potting mix on top of the agar layer,

The time saving benefits of this process are enormous. As noted in Chronicle II, fully separating each flask and compotting the seedlings took up to 45 minutes per flask. For these five flasks potted with agar intact- total time of under 1 hour, and remember I did a lot of work removing some agar and splitting each flask into two clumps. Had I not done that, I would have spent about 15 minutes on all five combined.

Chronicle IV to come over the weekend or early next week. That one will be fairly lengthy. I will spend some time on the potting process, but a good deal more on the growing conditions, watering cycles, my own technique for quickly monitoring plant condition on a daily basis, and how everyone is doing two weeks after being exposed to the outside world for the first time when the flasks were opened.
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