Sobennikoffia robusta

[Keysguy]

I did a search and was only able to find a couple references to this plant in these forums so obviously not a plant that you come across very often. Honestly, I had never even heard of Sobennikoffia when I first saw the plant and had to go look it up to see if it was something I could grow. There's not a lot of info anywhere on this genus that is from the northwest corner of Madagascar and are related to Angraecums.

It had just the first sign of a spike starting when I bought it about 3 months ago. It was progressing well so I packed it into the car for the trip north for the summer so I could see what it looked like. Another keeper! I love the flowers which, shape-wise, resemble a cornucopia to me. They are pure white with a pale green center and a very faint sweet evening fragrance. Flowers are roughly 3" long by 1 1/2" wide in the front. There are 3 spikes here. The plant is an epiphyte and looks just like a medium sized Vanda.

What little info I have found claims these guys are temp tolerant (cool to warm grower) and want lower light than vandas as they grow at the base of mature trees.

Worth adding to your collection if you can find one.

[WaterWitchin]

Love those blooms! Nice one.

[estación seca]

That is absolutely beautiful!

It took me a long time to find one Mine isn't flowering sized yet. It came from Louisiana Orchid Connection.

You have flowered it well, so you figured out how to grow it in your conditions. I wouldn't change anything. For others here I will offer some suggestions from a true expert who knew this plant in habitat.

My departed friend John Lavranos was a well-known plant explorer, especially for his work in the Horn of Africa, Yemen and Madagascar. He also described new species of Encephalartos from the Republic of South Africa. He discovered or described more than 10% of all known Aloe species.

I met him when he and Gary James of California were botanists on a Madagascar plant tour organized by the Cactus and Succulent Society of America. We didn't go to that part of the island. However, he told me I need to grow this plant because it should do well for me outside! I was quite surprised, but John visited Arizona in 2009 for the Tucson CSSA Convention, and he also visited the Phoenix area, so he knew our summer climate.

He told me they grow at the bases of trees, where they often receive full morning or afternoon sun. This is a very warm and humid part of Madagascar, with daytime temperatures usually over 85 F / 30C. They grow in leaf litter, with roots extending into the loose soil and gravel.

He told me he grew it on his west-facing patio in Loulé, Algarve, Portugal. He said his temperatures are not quite as hot as mine, but could easily go above 40C / 104 F on summer afternoons. His plant got hot western sun. He also said he frequently had low humidity.

He said to plant it in pumice in a wide, shallow clay dish, and to cover the top with leaf litter from my native mesquite trees. He watered his almost every day in summer, less in winter, but did not let it go dry.

Mine arrived in September 2021 in a pot with a few chunks of large bark. I moved it to a low clay dish with pumice, as John recommended. It had about four long roots in mostly good condition, wound around the inside of the pot. I put it outside on my west patio in very bright shade, and did not let it go dry. Daytime temperatures were in the 100-110 F / 38-43C range, and the 80s F / 26-32C at night.

It sat there without growing. The oldest leaf slowly turned yellow, then fell off. As cool weather approached in late November I moved it into my sunroom, to a spot next to the glass where it got a few hours of direct sun in the morning. The sunroom is generally in the 80s F most winter days, and more humid than outside here.

It did nothing all winter. When temperatures began rising in early March it began making two new leaves at the same time. I can't see the roots. I have left it in the sunroom because I don't think it's fully adapted yet to its new container.

I hope it eventually begins growing vigorously. Then I will put it outside. I won't put it where it gets full sun except perhaps in early morning, because there is a large difference in leaf burn between 104 F and 115 F.

[DeaC]

Love the way these grow as I'm a sucker for cascading over edge of baskets or coming out thru the bottom. Looks like fireworks and so lovely. Well grown.

[smweaver]

Wow, those are incredibly beautiful. It's kind of frustrating when you find a not-often-grown species that's hard to find cultural information for. But you've definitely done a great job with it. Now I need to go find one!

[Keysguy]

Thanks everyone. Another interesting factoid on these guys is that the flowers will turn creamy yellow (like the one at the bottom in pic above) within 24 hours of being polinated. The one you see has done just that. When I first saw it happen I was wondering how it had been pollinated because it's being kept on my screenporch for the summer. Well, upon closer examination I noticed that the opposing flower had a chunk of pollen on its labellum which you can see has a very pronounced point on it. What I thinked happened is that blowing and bouncing around in the wind, its labellum poked into the opposing flower and caught the pollen causing the violated flower to believe it had been polinated so it acted accordingly. I believe my assumption is correct because there is zero evidence of a seed pod forming.