repotting

[Hummer344]

Good Morning all,
I would like your input on re-potting healthy orchids. I have seen some that re-pott their orchids every year regardless of the status of the potting medium. It seems to me thats a little wastefull. How do others gauge their re-potting? I have several orchids that have been in the same potting medium for 3 years now. They seem healthy enough, they don't seem to heavy for their pots, and do not have over crowded roots and are not growing out of the pot.
Thanks
David

[jerrymeola]

It is a major fault to think all orchids re-pot the same way or on the same regularity.

Papheopedlium like re-potting into fresh mix as often as every six months. Cattleya can go two years between re-potting but I think you get better growth and larger plants with potting more often. Oncidium sometimes seem to go forever without new medium.

I think most Cattleya do well with a yearly re-potting to loosen the mix, and can be re-potting back into the same mix and pot, with a possible re-position.

Most of the time when someone is talking re-potting they discus the needs of Cattleya, and should be specific about this. I think Cattleya roots rot on a regular basis and discarding old roots on Cats is like cutting our finger nails. I like to remove Cattleya from the pots, cut off old dead roots and loosen the medium. Old Cattleya, that are not re-potted regularily, grow into a circle and the center dies off. By this point it is usually too late to re-pot without dividing the plant.

I feel with Cattleya a regular re-potting is necessary to get that specimen plant, certainly it speeds up the growth.

[Tobi]

I agree with Jerry on the Catts. I just repotted 2 of mine that were forming new growths
and roots. They were at least 3 years since last repot and the roots were circular and
the center had dead or dying roots in a cluster. From now on I will repot at minimum 2
years.

Phals, I repot yearly; Paphs, every 6-12 mos. and my Oncidiums about 2-3 years.

[janet_a]

definitely depends on the plant and the medium, and your conditions. most of my phals are in cheap sphag, which "concretizes" after a year or so, so i try to do them every 12-18 mos. my catt is very happy no matter what it's in; i wait til it's sticking its roots out the bottom of the pot to repot (generally 2 years). i'm going to try and make a point of doing the paphs every year whether they want it or not. my hwra lava burst gets done when it's crawling out of the pot. (its grows pretty quickly.)

that said, you will find reputable growers who insist that ALL plants must be repotted every 12 mos no matter what. then again, there's another very reputable phal breeder out there who not only repots every 12 mos, he removes the bottom two leaves of each plant when he repots.

[Andrew]

To a large extent, your choice of media will govern how often you repot. While some genera eg Paphs, Masdies, etc prefer fresh mix regardless of the media used others either don't need yearly repotting or worse resent it. Cymbidiums for example do not flower well after repotting. Many Dendrobiums also do better with infrequent repotting. Sphagnum will fall apart within a year of heavy fertilising (orchids like sphagnum more than sphagnum like orchids). Reasonable quality bark will last around 3 years depending on grade and how forgiving the orchid is of partially degraded media. Coir chips have a similar life span. Inorganic media like lava rock and the various expanded clay products do not degrade so media life span is largely dependant on your orchid.

[kmarch]

I second, third, and fourth those who have said it depends on the plant. Here's what I do:

Paphs & Phrags - once a year, after bloom or in spring

Cattleya Alliance orchids - every 2 years although I am currently running an experiment with 2 Cattleyas I received potted in pea gravel, these are going on 3-4 years still with good roots, growths and blooms

Coelogyne - only when absolutely necessary because they sulk when repotted

Dendrobiums - most of mine are mounted, the others, mainly hardcanes, about every 2 years

Cymbidiums - whenever they outgrow their pots (don't take my advice on these, I am lazy with my cymbids)

Andrew also makes an excellent point about it depending on the mix.