Repotting Hybrid Oncidium

[MightyMike34]

I have had an oncidium for over a year now that was in bloom when I bought it for my wife and has not bloomed since. It is growing quite impressively, (at least I'm impressed) and has more than doubled in size. It is under no special lighting, as our apartment has TONS of natural indirect sunlight. I have (admittedly, relatively blindly) purchased some fir bark mix containing perlite and charcoal as well as medium coconut chips. This purchase was basically an attempt to match what I think it's potted with now.

Advice on how to best repot would be great. Thanks all

M

[mayres]

Welcome to the forum MightyMike34 - can you update your profile to show where you live - in case this might influence the culture tips others might have for you.
Is the fir bark on the small side? Usually oncidium type orchids are planted in the smaller sized fir bark due to their fine roots. The coconut chips will do nicely to help the mix retain moisture. In general what you have planned sounds good. Are the leaves of your plant a DARK green? Oncidiums need quite a bit of light - morning sun - like from an east window would be good. South and west could be handled as well depending upon distance to the window(s) and maybe filtering. Strictly indirect light is probably not going to be enough to get your plant to rebloom. When you repot your plant push the oldest growth to the edge of the pot and give the growing leads some root to throw out another growth or two if possible - it is a delicate balance to keep the pot size down as much as possible and yet keep the plant inside the pot. They can grow over the edge in a hurry some times. You might post a pic if possible for additional comments/suggestions - does your plant have a name? This might also influence suggestions if folks know the genetics involved.

[MightyMike34]

Hey! Thanks so much for the quick reply, I tried to post pics, but I'm too new a member, soon, a few posts and I'll be up and running. I could very easily move this guy, and my others to a window where they will get even more light, which sounds like an obvious next step. The leaves are not dark green, but very green. Darker/richer green is better? The stake reads "HYBRID ONCIDIUM ORCHID Onc. Gower Ramsey" and I live in Jersey City, New Jersey. I have a 90gal open-topped turtle tank in the same room (evaporating about 4 gallons every three days) and so it's moderately humid in here. Are there any specifics about keeping the medium moist/wet or not when repotting? Any times to definitely NOT re-pot? and are you suggesting that the new pot only be slightly larger than the one it's currently in?

[MightyMike34]

I also purchased some sphagnum moss for my phals, but there is plenty to go around if this should be thrown into the mix?

[Orchidflowerchild]

Actually, a brighter, yellower green indicates optimum lighting. As mayres said, the plant needs a good deal of light to bloom, about 2-3,000 footcandles. TO give you a point of reference, full sun in florida is about 15K fc. Light is the basis of autotrophic systems, and in able to have enough energy output to hold a very metabolically expensive inflorescence, there has to be enough sun enegy input over the year.

As for potting, you will need to presoak your media at least overnight. I would recommend doing so in a bucket to which you add a couple or three drops of Superthrive (a root stimulant, easily found at Hom Depot for ~$3) and a drop or two of dawn (as a surfactant). I would even go so far as to soak the mix for two or three days. Fresh bark has water-repellant properties, and will take time to wet in-pot, which can cause considerable stress on the plant. ALso, I would repot only if there are new roots under 1" long emerging from the base of the new growth. WHen repotting, you are invariably going to damage some roots, and you want to encourage the plant to fill the void with fresh new roots, ASAP. WHen you *do* repot, remove as much of the old media from the roots as possible without unnecessarily breaking roots. Also, presoak the plant for an hour or so, so the roots are at their most pliable.

ALso, keep the tag from the pot. First, so that you don't have a rouge NOID (no ID) on your hands, and second because you can write the repot date in pencil on the tag and keep track of repotting, that way.

Tell me, do you plan to use a plastic or a clay pot?

-Cj

[mayres]

Good advice.
Mighty - yes, only a slightly larger pot - enough to accomodate a year's new lateral growth. Large pots tend to not dry out evenly and potentially cause root issues. I have one of those plants as well and it has not bloomed either for well over a year - I have it good east light for six months outdoors and it still didn't bloom - so I'm thinking it might be hard to over-light this particular plant? It will tell you if it is getting too much sun by getting paler and paler if it becomes an issue. Of course none of us wants to put any plant immediately into significantly brighter conditions than what they are used to all at once. GRADUALLY aclimate them to brighter conditions by increasing the period of sunshine over a week or two - or you will get burns on the leaves - typically a late spring/summer potential problem. It can probably take about all the sunshine you can give it this time of year except maybe up against a southern window where the glass might magnify the heat. Good air movement helps to negate heat buildup as well - the more plants you acquire the more you might want to consider a small fan in the area.
Others will disagree, but I would stay away from the sphag personally. Enjoy! mike

[Tobi]

I grow several Oncidiums in my east window of my 4 season room and they seem to
really love the early morning light. I purchased a couple in sphag moss and had a more
difficult time monitoring the watering conditions. Like Mike stated, some people have had
luck with sphag, but I found that a medium grade bark (or fine grade is good) with
charcoal and perlite works great. As far as their reblooming, I found that they take a
little more time to acclimate to their new environment than some other types, but once
they do, they will continually rebloom yearly. So be patient and give it plenty of
good air movement and it will do just fine. Good growing!!

[articuno75]

My Mtdm Bartley Schwarz is in a spagh/bark/charcoal mix, more spagh than anything else-Say 85%. It depends on your conditions I guess. If you are in a really dry area, I'd go for the Spagh. It helps retain moisture for these guys and they seem to be pretty thirsty plants. My apartment is like a desert and the spagh really works for me.

As for the Spagh and Phals My Phals didn't go for it and I had a lot of root loss believe it or not. They liked the "bark mix" better. But again with Sahara conditions I went with this stuff that contains coir, perlite, and charcoal. Does wonders and saves on watering time

[MightyMike34]

Thanks for all the replies. You guys are great! I'm going to post some photos of the plant as well as the pots I was considering, I have two sizes, both plastic.

[MightyMike34]

should the mix be soaked as a complete mix of bark/charc/perl?

[MightyMike34]

Onc

[MightyMike34]

pots

[Tobi]

Originally Posted by MightyMike34

should the mix be soaked as a complete mix of bark/charc/perl?

Yes Mike. Soak it for at least 24-48 hrs. to ensure good water retention. The
plant looks goods. The older pseudobulb is slightly wrinkled, but that is not
totally uncommon in Oncidiums. The new pseudobulb looks very good.

[articuno75]

Plants look great! but I do see where a couple of the leaves have an "accordian" look to them. Do check your water levels on these guys cause they don't like to get dry and that's what causes this.

[MightyMike34]

Thanks! I'm glad it's doing well. Any thoughts on the pots?

[articuno75]

The green one would be the better size, but my Bartley Schwarz is in a pot about the same size as your plant now. I thought these guys like to be root bound? Mayres? Tobi?

[Tobi]

Although Oncidiums like to be confined, their root system once established will grow
rapidly and massive. Thus it wouldn't hurt to slightly overpot (and I mean slightly). Just
make sure the roots fit comfortably in the pot.

[mayres]

Personally I would keep it in the same size pot - certainly no bigger than the green pot. I would personally use a finer bark mix than it is in now. I agree with Tobi - soak your entire mix for awhile before using. When you repot push that old staked pseudobulb up against the side of the pot.

[MightyMike34]

-- soaking --

[MightyMike34]

Any advice on how to deal with these roots that seem to be climbing the pseudobulb out of the mix? Should they just be left to their own devices when repotting?

[fred]

your Oncid looks fine in the post its in you could however use the same pot if you do wish to re pot
the way the roots are growing is normal I would not try to make the roots go into the mix as they are not long enough to do anything with because if you try to move the roots so young they will break.
I would only use the next size up pot the green pot looks a little to large

[MightyMike34]

Thanks Fred,
I do appreciate everyone's advice! How would this advice be different for repotting a phal?