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 this, whenever you are change the local root zone conditions – whether that is by changing the medium (any, not just semi-hydroponics related), or drastically change the overall conditions, as when a plant formerly grown in a Hawaii greenhouse is moved 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. The plant will continue growing as if nothing has happened, or in the case of the improved airflow of my sphagnum-to-semi-hydroponics 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 semi-hydroponics is 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. It is also important to move to the final state immediately and to not try “transitional” set of conditions that are in between the old- and new ones. Doing this sets the plant up to do a second round of adaptation.
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.
Ray Barkalow has been growing orchids for over 45 years, and owns First Rays, which offers horticultural products to the hobby grower. He may be contacted at firstname.lastname@example.org and you can visit his website at FirstRays.com.