By Cheryl Harrison, Master Gardener
Yes, it is finally spring! We can feel the sun getting warmer and see the light lasting longer and so can your orchids.
Before the outdoor gardening season starts, have a look at your Phalaenopsis orchids … actually check all of your houseplants but I am going to stick with just Phalaenopsis orchids for now. Your orchids may have already started to bloom. I have 5 Phalaenopsis orchids and one of them has been in bloom for a couple of weeks. The others are not in bloom but, after inspection, I realized that they all needed to be repotted. How do I know that??
Orchids are epiphytes which means that they grow on other plants but are not parasitic so do not hurt the other plants. Epiphytes have aerial roots to anchor themselves to a tree, for example, or in a pot. The aerial roots pull minerals, moisture and nutrients from the air. They are not growing in soil. When I checked the medium in the pots of my Phalaenopsis, by gently lifting the plant from its pot, the medium had broken down and looked more like soil than the appropriate mixture of bark, perlite and sphagnum moss (or renewable coconut chips).
Phalaenopsis orchids often need to be repotted after purchase because they may have been in the pot for quite some time and the potting medium has decomposed or they may be in an incorrect potting medium. Incorrect potting mediums include anything that holds too much moisture and/or is compacted around the plant’s roots e.g. regular potting soil or a ball of sphagnum moss. They also need to be repotted every 2 to 3 years because again, the medium in their pots will have decomposed, begun to become compacted around the roots and hold too much water. Too much water will lead to root rot followed by a decline in plant health and subsequent plant death.
The other indicator that repotting may be needed with Phalaenopsis orchids occurs because the plant is monopodial which means that it grows taller with new leaf growth at the tip of the stem. The plant can end up top heavy and if not well anchored in its pot, it can fall over as flowers, stem and leaves are pushed up out of the pot by the roots. With repotting, you can settle the plants roots back down into the pot. If the potting medium is still in good shape, then it does not need to be replaced but if you are repotting the plant anyway then it may be a good time to replace the medium.
I have collected my supplies to repot my plants. Note that I am not going to disturb the one that is blooming. I will leave it until it is done blooming then repot because I do not want it to drop its flowers with the shock of being repotted. The flowers are way too pretty!
Now you know why my Phalaenopsis orchids need to be repotted, so check your plants before you get too busy with the start of outdoor gardening season … it’s spring!
For more information:
How to Repot an Orchid: Phalaenopsis, Chicago Botanical Garden