Repotting Oncidium sphacelatum

Our Oncidium sphacelatum was getting a bit too big for its old 20cm pot, so I decided to try my hand at re-potting. I've done a few Phalaenopsis before, but they have nice, big, chunky manageable roots. Oncidiums have rather thinner roots!

Oncidium sphacelatum

Too big! Note new shoot and roots.

Testing to see if 25cm is just about big enough!

I got hold of a 25cm pot, put about 2-3cm of fairly coarse gravel at the bottom (drainage and weight) and a thin layer of bark-based orchid medium.We found a 30cm pot last weekend, but I deemed it far too large to pot on an orchid, which in the experience of most growers prefer to be a bit "pot bound".

Gravel

Then it was time to see what the roots looked like after sliding it out of the pot.

Wow, that's some serious root system!

I was initially thinking of just "potting on" - i.e. putting the existing root ball into a bigger pot and cramming some medium down the sides. However, when I lifted the root ball upright, stones and old potting medium started falling out the bottom, so I decided to do it properly, and remove as much of the old medium as I could along with any obviously dead or dying roots. Interestingly, the crazy root growth was mainly just around the outside of the pot, with the central part of the pot more or less empty of roots. I rinsed the roots with my normal RO orchid-watering water - you should have seen the colour of the water in the sink after that (black!) - guess the medium was starting to degrade somewhat. 

Old medium plucked out, still masses of roots!

In its new pot.
Note old medium and roots underneath

Top down view. 

Turned out quite well, I think, and it seems very stable too. Hopefully, this plant will enjoy it's new home. There were quite a few new, active looking roots coming out of the pseudobulbs and new shoots, so hopefully, it won't sulk too much. There seem to be quite a lot of new pseudobulbs and shoots, so hopefully sometime next year we should see a nice display of flowers! Unfortunately, that light green ceramic pot no longer fits this one inside, so it's back to plain boring fake terracotta!

This plant was previously featured in these two posts: Pests: Black Fly, where it lost all its sprays of flowers to black fly and New Plant: Oncidium, where you can see it in pre-black fly blooming glory!

Re-shuffle, Re-plant, Re-decorate...

After getting a light meter, we've started some re-organising at OOAB, as I don't feel some of the plants are getting enough light. We also did some fairly major re-potting to our little succulent collection over the weekend, as several were straining their pots or otherwise looking sad. Here are some pictures of the results quickly snapped this morning, and a closer look at some of the plants.

"Shadecloth" (net curtain) added, we moved (L-R)
Cymbidium 2328 (Annie Kelly 'New Horizon' x Enzan Shining 'Geyserland')
Dendrobium kingianum
Laeliocattleya Tropical Treat C0341
Slc. Kararizi Dawn 'Red Star'
Also: payday and big queue for bank (in the street)!

I'm also thinking the Ascocentrum and Rhyncostylis might like to move closer to the light, and perhaps some of the other light-lovers - but we need more space there... Will have to Build Something! This side (pic above) of the balcony gets an hour or two of direct sunlight in the afternoon; we added some net curtain to help diffuse this a bit.

As a result of the move,
the "orchid shelf" is looking a little more barren
(also the Oncidium is currently on quarantine in the bathtub,
until I'm sure the black fly are dead).

In non-orchid news (bear with me, Orchidophiles!)...

On a trip around Sunnyside Garden Centre in Grahamstown (main purpose: obtain sand for making potting mix and new larger planters for succulents), we found some bags of fluorite/calcite stones at the bargain price of R30 each. These have now been artfully arranged around the succulent collection, which gets several hours of morning sun. Kind of hard to see in the picture, but I'm assured it looks Awesome. Will have to play with the lighting sometime to see if it can be rendered so on camera! As with pretty much all the photos on the blog, clicking on the picture will take you to a larger size so you can see what's going on.

Lots 'o Rocks (and plants).

Repotted succulents
Transplanted succulent seedlings (bonsai pot rear left)
New succulent seeds (under glass)

Not sure what this is, but I like the leaves a lot.
Has been flourishing since moving into this pot a few months ago.

Fockea edulis
This little plant had filled it's tiny old pot right up.
Time for more space!

Four of the baobab seedlings, coming along nicely.

First baobab to sprout, in supplied bonsai pot, new leaves opening.

Our African violet has come into bloom again, yay!
I imagine it's enjoying all the humidity it gets now.

One of our 2 Tillandsia caput-medusae bulbosa.
I'd like to find some bark or similar to mount them on.

And now, back to our regularly scheduled programming...!

The three Disa bivalvata we unflasked a few weeks back seem to be doing OK; here's an updated picture from this morning:

Disa bivalvata community pot

And one of our Paphiopedilum is about to open a new flower:

Paphiopedilum Onyx

De-flasking a micropropagated Disa

Whilst at Kirstenbosch National Botanic Garden in Cape Town on a boiling hot day, we found a some micropropagated Disas from the Cape Institute of Micropropagation and decided to see if we could manage to get them to grow; we also conveniently found a sphagnum-moss based potting mix there too, so we grabbed that whilst we were there.

Having pretty much outgrown its little flask, the Disa bivalvata was opened on Sunday, had distilled water added up to the top of the label as per the attached instruction leaflet, and after three days like that, it was time to pot up.

I sterilised a smallish (9cm) pot and some spoons in some hot water with Jik (household bleach) and then thoroughly rinsed it. The potting mix was rehydrated with distilled water.

You can see how ready it was to be potted!

I gently removed it from the flask with a teaspoon; the distilled water soaking loosens the agar up quite nicely.

Disa bivalvata unflasked, with some agar still adhering.

Given the rather nutritious agar and the susceptibility of Disas to fungal and bacterial root rots, it's a good idea to make sure all that gel is washed off the plants, roots and tubers. I used a pressurised spray bottle turned to a jet of water with distilled water to gently blast the agar off; this works quite well and is probably kinder to the delicate little plants than trying to remove it with tools or anything else.

Cleaned plantlets. 3 were in the flask.

I then mostly filled their pot with sphagnum-based potting mix, and gently packed a little ball of it around the roots and tubers before putting each plantlet into the pot and then putting more mix between the "root balls" to keep them in place.

Plantlets now in pot.

Old and new home (taken with dead flash batteries, hence the blur...)

Added to the collection!

The plants were then watered with 4g/l Fungi-Nil (captab) solution in Aquelle spring water; the instructions said to water with a "mild fungicide"; this morning I received an email from Hildegard Crous who runs the outfit that does the micropropagation:

The Captab works very well as it is somewhat systemic, otherwise the better known fungicide to use is Dithane, both can be used at the recommended dosage.

This is mentioned in the Grow Disa book, but I will improve it on the instructions label,

I put them into the cut off bottom of a water bottle and topped it up with distilled water as you can see in the picture above. So there we go. Hopefully, the plantlets take to their new home and our version of green-ish fingers! I've just ordered the Grow Disas book from SANBI as my regular online book dealers don't seem to stock it.

We bought Dr. Louis Vogelpoel's Disa book at Exotic Plant Company, but it seems a little dated. Pretty much all the information in it is available almost verbatim online in these culture notes.

Disas.com has a very comprehensive guide to deflasking.