Repotting

Hi All,

Was just wondering what various growers undertook with regards to repotting. I use basically orchiata in various grades and it has a slow breakdown time for me. I have started to pot on which is less disturbance to the root system and they seem to grow on from their existing root system. Should all the medium be removed, then even using orchiata, the plants seem to lose most of the roots and the plant gets set back until new roots have formed. This may be down to the ph which I assume will be down to existing feeding application. On repotting I add root growth hormone for a short time and feed weakly until new growth becomes established.

Any ideas as to what successful methods growers use for smaller and established plants would be great.

Gary
UK

Traditionally, they told us to remove all the old mix and cut back dead roots. This may be a hangover from when they used leaf mould etc. But unless your mix has broken down to mush, I think potting on is quite ok and could be even better than disturbing the roots.
If you go to Tanaka's site and read up on delenatii, he mentions that even though the mix in the small pot was badly decomposed he always just put them straight into a large pot without touching the old mix and says he never had a issue.
In horticulture we are always told that placing a fine mix next to a course one is a big no no as the fine mix retains way too much water but it seems that in some cases it doesn't matter!
I guess orchid roots are a different animal....

Im impressed with Orchiata based mixes. I 'shake' out the old mix and replace. I think a healthy plant will grow new roots (I have mostly multi's)

I have repotted some plants that were in orchiata into completely new orchiata and they seemed to lose most of the existing roots and slowly grow new ones. This has set the plants back a while. I've heard that the ph of the medium is affected by the feed given. Would the plants uptake of nutrients from the new medium be affected? Have growers had success using various grade orchiata only or have they added anything else. I also grow mainly paph multifloral.

Gary
UK

I can tell you that I had the same experience with orchiata and paph/phrag. The first year they did good, good roots, and good growth. Then when I reported the second year in orchiata I saw some plants had lost most roots and didn't grow many more. I figured it was just isolated to those few. Then the third year most did not grow well and it was spring time when they should be growing many New roots. I reported back to standard first bark with permits and charcoal and most of the plants grew a ton of roots. Some did not recover and had to be thrown out. I don't know what the problem was, and it was not water or fertilizer because most received very little fert, and I adjusted my watering to suit the orchiata

Didn't someone here say one should add extra calcium to the mix after the first year?

SlipperFan said:

Didn't someone here say one should add extra calcium to the mix after the first year?

Click to expand...

In what form, how regularly and how much?

Gary
UK

I don't remember the specifics. Maybe someone else will.

Carper said:

In what form, how regularly and how much?

Gary
UK

Click to expand...

I bought crushed oyster shell from Ravenvision orchid supplies department and instruction said:
Add 1 heaping teaspoon to the pot every three months.
I am doing it now but not for long enough to see any results.

Here is the description of the product from their website :
Oyster Shell is a natural organic
source of calcium and trace minerals for calcium loving orchids such
as Paphs. It is 96% calcium carbonate , a gentle source of elemental
calcium. Use as a topdressing and replace when gone. The variable
particle size allows for immediate and long term release. Oyster shell
is basic and is used to raise pH in orchid mix.

when buying oyster shell go to a farm supply place they have 10 kilo bags for a few dollars,will last a life time.

Yep. Lots of them around where I live.

I agree with potting one method for the same reasons that others mentioned.

Messing with the roots seem to disturb the plants way too much and hence the set back.

I only remove old potting mix if they come off on their own when I take the plants out of the pot.

sometimes this worries me as I constantly think what the old mix in the center of the root ball would do to the plants, but so far so good.

With pot on method, I have not had any set back and repotted plants grow very well.

I don't think adding oyster shells is necessary as long as balanced fertilizer is regularly given.
I have never used shells or lime stone in my mix. no issues ever.

This fall, I purchased several Deperles that were just potted up in orchiata. I've never used the stuff myself. But now I am concerned about their health. Should I top dress with oyster shells? Repot this spring into my regular mix? This does have me in a quandary. I use r/o water w K lite fertilizer for them.

I think orchiata is treated with a calcium substance at time of manufacturing, I also have had bad results with orchiata so I got a huge bag of small and medium fir bark and mix the two, orchiata and fir bark and have gotten better results

I would top dress orchiata with a teaspoon of oyster shell per 4" pot. (or include in the mix)