Seedlings

August 11 (Day 1)

These seedlings have been sitting in the mail for five days! Even so, they look pretty healthy. The Dendrobiums are in better condition than the Vandas, most of which have some browning basal leaves. I think it’s heat stress—they are cool-intermediate growers. I washed the agar in a mix of distilled water and hydrogen peroxide while laying them out on the trays. Not knowing how big the seedlings would be, I made the mistake of not reserving enough space, and not sterilizing enough sphagnum moss. I haphazardly cobbled together something for the rest of the vandas, pots which had been washed but not sanitized. I rubbed them with alcohol. Another problem—I had decided to pressure cook the media to sanitize it, but I did it a little too late in the day, expecting the package closer to 4 or 5. The medium was piping hot and I ended up surrounding the bowl with ice packs and dunking it in cool water, squeezing all the water out, hoping that would be cool enough. If my seedlings die, it might be because of temperatures.

There are 24 dendrobiums, and 45 vandas. I potted up some really tiny vandas, but if you just count the medium and large ones, their numbers are closer to 35.

It’s 89 degrees in the big container, thanks to the heat wave. I’ve put ice packs around it in the hopes I can keep it under 85. Is it too hot for them, or are they simply adapting to it?

I’m slightly worried about airflow for these vandas. When the wine cooler comes, I’ll vacate the Ecuagenera plants from the 20 gallon aquarium and then move all the seedlings there along with the fan and the lid.

August 17 (Day 7)

Well, I guess we’ll never know. The weather has cooled down to a very nice and mild 65-80 range, and I didn’t note any devastation in the mean time. I did end up transferring them into the aquarium:

The one issue I did notice is that some of the dendrobiums have dieback on the leaf tips, which may have been burned or dehydrated somewhat. I am watering the individual compots more frequently now; I think the dendrobiums suffered a bit from desiccated roots.

August 18, Day 8

Today I encountered a problem with blue-green (and some white) mold spots. I washed off the roots of dendrobiums, clipped some older vanda leaves, and changed the medium on three dendrobium compots. I believe the mold was introduced through my use of diluted Neptune’s Harvest fish/kelp fertilizer. This would make sense considering that I’ve sometimes opened the bottle to find mold around the lip, which I would just remove it manually. I am only going to use inorganic fertilizers for future watering of seedlings.

On the upside, noticed some new roots poking out here and there. I think the mold isn’t that bad because it wasn’t attacking any of the fresh growths. I probably shouldn’t have used hydrogen peroxide in the first place; it may have killed off some of the Trichoderma harzianum (in RootShield) that came with the plants. Luckily I ran out of peroxide, so I wasn’t tempted to blast them with it again. I will buy an inorganic fertilizer sooner or later so that I can fertilize them without risking the introduction of mold. The blue mold is probably either Aspergilius or Pencillium, neither of which are extremely damaging.

I wonder if exposing plants to UV radiation helps control mold. If so, windowsill culture would be best. But then greenhouses wouldn’t be, as they tend to absorb UV light. I’m guessing that the amount of UV necessary to do so would also damage the seedlings, so UV isn’t an effective anti-fungal in this context. My mold issue can probably be kept under control if I just switch to clean water for a while and inspect the roots every day. But I should be mentally prepared to lose some plants!

August 19, Day 9

I’m not concerned by the mold anymore; not seeing much of it come back. But I am seeing more pronounced leaf-tip burn in the Dendrobiums. Am I exposing them to too much light, or are they just finishing up with whatever trauma they were previously exposed to? I kept the lid off for most of the day. Humidity dropped to 91.7%, no lower. The Vandas look good, I can see new leaves growing. Taking the lid off may have exposed the Dendrobiums to too much light and wind. They have thinner leaves and roots, so I expect them to be more sensitive. I see conflicting advice on the web about the timeline for hardening off seedlings; some people are very gradual with the removal of the lid, whereas others recommend inducing more air circulation within the first week I think my ambient humidity is high enough so that more air exposure isn’t such a bad thing. I do think I’m being too harsh with the light, however. I hope this doesn’t kill my stronger-looking dendrobiums, as it’s the largest ones which are most affected.

September 17, Day 38

I am feeling much more confident! Seeding good root growth and foliage growth, less or no leaf tip browning, and haven’t had to cull any of the weaker plants for some time. On September 5th, I had found some fungus gnat larvae at the roots of several dendrobiums, probably eating away at a combination of dessicated root matter and actual fresh tissue, but I haven’t noticed any new issues since.