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!

Pests: Black Fly

This morning whilst doing our watering we noticed a few black bugs crawling over the pseudobulbs on our Oncidium sphacelatum. Turns out "A Few" was actually Hundreds when we looked up at the racemes. Almost every flower has like 20-50 little black aphid type creatures clustered around it, merrily sucking away. No wonder the flowers were starting to look sad :/

Black Fly Of Doom

Lots of Doom

Not just behind, but in and on the flowers.
And look at those shed exoskeletons. :/

Extreme closeup (crop)

 The Oncidium was then immediately relegated to the bathroom (quarantine and spraying area), had the worst affected (and mostly dead) racemes trimmed off (tragic!), and was then sprayed with Dursban (Chlorpyrifos) 1ml/l with 1ml/l of Bladbuff wetting agent. Made sure some got into the crowns between the leaves, just in case...

I really, really would like a lot of lady bugs and whatever eats/parasitises whitefly and red spider mite...

So, if your flowers look sad, don't assume they're done flowering... have a closer look :/
We'll be keeping a close eye on the rest of our plants for the next couple of weeks.

The photographic models got flushed down the toilet, and the other racemes were tossed in a plastic bag and immediately removed from the OOAB premises... Argh.

New plant: Oncidium

At the last meeting of the EPOS, just before I was about to leave, Abraham Marais very generously gave me a spectacular Oncidium sphacelatum. I immediately forgot the particular species/hybrid name [Edit: I found out!], but will find out. Anyway, here are some pictures of it in its new home and a closeup of one of the flowers.

New Oncidium sphacelatum dominating the OOAB collection.

Part of one of the long racemes of flowers.

Close up of one of the flowers.

Oncidium is a fairly large genus of some 330 species, native to Central and South America, with a few species extending into the Southern USA. A fairly comprehensive guide to suggested culture of this group can be found here.

Eastern Province Orchid Society

The EPOS logo

I've just returned from a dash down to Port Elizabeth and back for the first meeting this year of the Eastern Province Orchid Society (EPOS), which we signed up for last week.

This month's talk was by Chris Randlehoff, an accredited SAOC judge and clearly quiet a major orchid grower too - he even won the South African Orchid Council's Orchid of the Year award in 2009. Chris traveled from Eshowe in KZN to talk about the genus Lycaste and its hybrids and some closely related genera (Ida, Anguloa) with many, many picture, noting what made "good" plants in a judge's eye and also culture requirements. It's quite amazing to see the vast variety of orchid hybrids that have been made from just a few original species in this group. He noted that fertilising most orchids with additional Calcium and Magnesium had generally made his plants much stronger, so we might just have to try that! I also noted that all the plants that weren't strict species didn't have italicised names (not even the genus) - so I've got some editing to do...!

After the talk and tea, Chris went through each of the plants members had brought with them, commenting on their appearance and culture, sometimes suggesting things members might do to improve them; with several plants, he noted that they were "The Best XYZ he's seen in South Africa" - so the EPOS members evidently know what they're doing!

The society is very friendly, and many of the members brought along some spectacular specimens from their collections. I think the most spectacular were a bowl filled with the same species of Phragmipedium I bought, some fantastic Vanda hybrids, a large Mokara and an incredibly deep purple Dendrobium phalaenopsis hybrid - but it was pretty hard to choose what was best!  "What orchids do you grow?" is evidently the preferred opening question at orchid clubs (quite understandable!) - I almost felt I should have had a species list with me, but as much as I think we might be going a bit mad in our "balcony rainforest", we're not only rank amateurs, but scarcely have any plants compared to many of the members. So if anyone wants a list, well, here's my blog, and there's a plant list in the Orchids tab at the top - which I now need to update! :) The members are also generally keen to not only talk orchids, but pass on tips and experience, which is a pleasure. Unfortunately I can't quite remember all the names of the people I spoke to, but I did have a chat with a guy called Stan Wedge, who was recently made an Honorary Life Member of the society. He started growing orchids in 1978 - the same year I was born. He's also no stranger to national awards, winning an orchid of the year for his Dendrobium kingianum "Stan' in 1999, and species of the year in 1993.He also said that he had "about 600" flasks of various things around one of his growing rooms, and makes his own flasking medium out of a fairly long list on ingredients. If he has 600 flasks, I can only imagine how many actual orchids he must have... Hopefully, we'll have something worthy of talking along to the next meeting! I had considered taking some plants along, but I was in a bit of a rush to get there, and some of the orchids (the paphs, Zygopetalum and the Ascocentum) are a little past their best - or not quite there yet (the Slc. Kagaribi Dawn 'Red Star'); I also didn't feel happy taking one of "our" plants when it was just me attending!

I bought two orchids, a Phragmipedium caudatum and an aptly named Lycaste aromatica. I've wanted a Phragmipedium for a while, and the idea of having one of the species covered in the talk appealed - as did its intriguing cinnamon scent!

I asked the club's chairman if he might be able to bring me a few items from the EPOS Shop to the meeting, which opens twice a month on Sundays; as we're going to a wedding in Cape Town this weekend, we couldn't really make the next open day (this Sunday), and they sell some quite useful stuff which we need (like an acaricide for adult red spider mite, and some other fungicides I can't find here), which he kindly did.

On my way out, the chairman (Abraham Marais) asked if I might like the Oncidium he had brought for the show table - I said I would rather, and asked him how much he wanted for it, but he point blank refused to let me pay him for it - so many, many thanks Abraham! He noted that he had "quite a few" - and by "quite a few" he meant about 100! My brain has forgotten the exact species, but I'll find out [Edit: sphacelatum]! Apparently it got relegated to the garden in a shady spot under a tree; this particular specimen has quite amazing sprays of yellow and brown flowers - seemingly hundreds of them - it's a stunning specimen that pretty much filled the back seat of the car. 

No pictures just yet, but I'll post some early next week.