You can find miniature sized as well as large sized orchids in this group. Cymbidiums are hardy orchids, these can be safely grown outside. As they can tolerate low (but not freezing!) to high temperatures without much damage to the plant. While repotting Cymbidiums keep the following things in mind.
Right time to repot Cymbidium orchids
Repot after flowering is over and the next growing season is about to start.
Repot the Cymbidium when the orchid appears crammed or overgrown in the containers and there is no space left for new growth to emerge.
Repotting can be done to change the decayed growth medium.
Repotting is one of the ways to remove diseased and rotting parts in orchids.
When not to repot
Repotting can harm your orchid if the Cymbidium is about to flowers.
Cymbidiums have clustered together pseudobulbs. Divide the pseudobulbs only when a group of at least three or four pseudobulbs can be formed.
How to repot
Collect the material required for repotting, place it together.
You will be requiring containers (like pots, baskets etc), growth medium, tools for cutting and separating the plant material, clean paper (newspaper will do fine).
Select the container in which you want to place your orchid. Choose the size of the container according to the size of the orchid, large pot for large Cymbidiums and small for miniature Cymbidiums. For fast growing ones, select a bigger container. Cymbidiums grow well in clay pots.
Choose a growth medium which retains a bit of moisture and is porous as well, such as bark pieces, coconut chunks etc. Discard your old medium. As it may be carrying pests, virus or bacteria.
Before starting to cut or separate your orchid, clean the tools in soapy water and wipe with alcohol. This is to prevent spread of viral and bacterial infections, which are easily spread through dirty tools.
Select a clean dry place to do repotting.
Cymbidiums can be divided by two methods:
1. Backbulbs: In Cymbidiums when the last seasons pseudobulbs shed their leaves, they can be reused to grow new plantlets. These are called backbulbs. These can be stored and healthy ones can be repotted in the next growing season.
2. Separating actively growing pseudobulbs: In case your Cymbidium is crowding the pot, you can divide the orchid in such a way that each group has three to four actively growing pseudobulbs. Cut the rhizome carefully without damaging any pseudobulbs. Remove rotted or diseased parts. Place the separated cleaned orchids on a clean sheet of paper.
Prepare your container. Add the selected growth medium, make sure there is an outlet for water drainage.
Place the orchid in the container carefully such that there is ample space for new growth. Cover the bottom of the pseudobulbs with rest of the medium.
Water the newly planted orchid sparingly and place it in warm shaded place. Let it get accustomed to the new setup. Shift when your see new growth emerging.
It is advisable to label your orchid. It will help in identifying the needs particular to that orchid.