This article is in response to the often-asked question “How long will it take for my plant to get reestablished after repotting?” – especially when a plant is first moved into semi-hydroponics. In fact, the phrase “transplant adaptation” is something of a misnomer.
Orchid roots grow tailored to the environment they are in, and once grown, cannot change. Because of that, whenever you are changing the local root zone conditions – whether that is by changing the medium (any, not just S/H-related), or drastically changing the overall conditions, as when a plant formerly grown in a Hawaii greenhouse gets to your windowsill – you have to be aware that the plant will need to grow new roots that are “right” for the new conditions.
If the old and new environments are similar, or the new one is an improvement (soppy sphagnum to moist LECA in semi-hydroponics, for example), there is no real adjustment necessary, and the plant continues growing as if nothing has happened, or in the case of the improved airflow of my sphagnum-to-S/H example, will take off and grow better.
If, on the other hand, the change in root zone environment is vastly different – coming out of dry bark and into moist sphagnum or semi-hydroponics, for example – the old root system may be virtually useless and an entirely new set of roots will need to grow before the plant has fully “adapted”.
Keeping those two extremes in mind, you can see:
- That the time period for a plant to become well-established in S/H is quite variable and dependent upon the particular situation,
- It is important to time the conversion to coincide with the formation of new roots, so that they can grow to function the most efficiently in the new environment, and
- One should go to the final state immediately, not try to do a “transitional” set of conditions in between the old- and new ones, as that sets the plant up to do a second round of adaptation.
I have found that the ideal set of conditions for a successful transition include all of these:
- The plant, and especially it’s roots are healthy and strong to begin with.
- The plant is actively growing brand new roots.
- The roots have been cleaned of all old organic matter.
- Mineral-free water is used to soak the medium and water the plant.
- The plant is kept very warm – in fact, I use bottom heat for all new plants these days.
- The plant is kept shady.
- The plant is kept in very humid conditions.
Those first five factors favor the stress-free growth of a well-adapted root system, while the last two minimize the stress on the plant while it does so.