This is one of the most common questions I get asked about orchids on this website. When your orchid’s leaves are limp and perhaps a but wrinkled it can be really difficult to tell whether your orchid needs more water or whether the soil has dried out properly for weeks and there is a problem with overwatering.
It can be frustrating because both overwatering and underwatering can look almost identical, but the real clues are at the roots of your orchid. Here is how to read the roots and an easy test you can do yourself to establish whether its overwatered or underwatered.
The Rapid Diagnostic Matrix
Before unpotting anything, this comparison gives you a fast first read on what you’re likely dealing with.
| Diagnostic Marker | Underwatered Orchid | Overwatered Orchid (Root Rot) | Healthy / Target State |
|---|---|---|---|
| Root texture | Brittle, dry, firm or papery | Mushy, squishy, hollow, or slimy | Plump, firm, and turgid |
| Root color (dry) | Silvery-white or dull grey | Dark brown, black, or yellowish-mush | Silvery-green to pale grey |
| Root color (wet) | Turns bright emerald green | Remains dark brown/black | Turns vibrant forest green |
| Velamen integrity | Intact, spongy layer | Sloughs off, exposing stringy wire | Firmly anchored |
| Pot weight | Feather-light when lifted | Heavy, dense, and waterlogged | Moderate weight |
| Substrate odor | Neutral, earthy, or fresh bark | Sour, stagnant, swampy, or rotting | Fresh woodland / clean bark |
| Leaf response to water | Re-plumps within 24–48 hours | Remains limp; wrinkles deepen | Remains upright and rigid |
If you can only check one thing quickly, what I do is to lift the pot as a shockingly light pot points to underwatering whereas a pot that feels heavier than it looks points toward waterlogged, rotting substrate.
The 15-Minute Velamen Response Test
If the troubleshooting guide above doesn’t give you a clear answer, here is a test that does. It is simple, and it works because of how the orchid roots actually function.
The botanical principle: The phaleanopisis orchid absorbs moisture through a velamen radicum which is a speciliazed multi layered outer coating of dead cells wrapped around the root’s central vascular core. The living, healthy velamen acts like a dry sponge and can turn from silvery white to a translucent green within seconds of being watered, which reveals the active chlorophyll layer underneath it. Velamen that has already rotted has lost this cellular structure entirely, so it can change colour and it can’t hold turgor pressure anymore.
The protocol:
- Unpot your orchid. I gently slide the rootball of the orchid out of the pot so I can see and handle the roots up close.
- Submerge the roots in lukewarm water for around 15 minutes, placing the whole root system in a bowl or basin and letting it sit there.
- Asses the colour of the roots and feel the texture. If underwatered…The roots swell in size and change to a bright green colour in minutes. When you pinch them the root wall resists and feels springy which is a good sign. If overwatered…the rotted roots stay brown and limp, without an visible rehydration and under gentle pressure the waterlogged velaamen slides off between your fingers, leaving behind a thin central strand, which is the exposed vascular stele. This is dead root tissue and the root won’t rehydrate.
This easy test removes the guesswork because we are testing the orchid root tissue’s actual capacity to rehydrate rather than just how it looks sitting in the pot.
Recovery: What To Do Once You Know Which One It Is
For an overwatered orchid (root rot)
- Remove the damaged roots. Using pruners that are sterilised in disinfectant (you can use handgel) and prune away every hollow, mushy or blackened root back to healthy green tissue, and don’t leave any rotten sections as they’ll spread.
- Treat the wounds. What I do is dust the ends with ground cinnamon as it acts as a natural anti-fungal to prevent any reinfection.
- Repot the orchid into a new potting medium. With the orchid in pine bark, ideally in a transparent pot (with slits in the side for added ventilation). Pine bark pieces are large and allow air around the roots and allow excess water to drain away and mimics the natural conditions of the orchids native medium (they grow on trees in tropical climates). Avoid using moss as it holds too much moisture.
- Give it a drying period. I would keep your orchid dry for 3 too 5 days, so that the roots can callus over before you water and mistthe plant again.
For an underwatered orchid
- Bottom soak a thirsty orchid. Place the orchid in a bowl of lukewarm water filled to around 80% of the pots height for around 20 minutes. This is enough tome for a dried out bark medium to actually absorb the water rather than letting it run straight through.
- Drain it thoroughly. What I do is let the excess water drain out for around 10 minutes rather than letting sit in water which can pool around the crown or leaf axils otherwise you trade one problem for another.
- Increase the humidity as it recovers. I like to spray my orchids with a mister but you can use a little plant humidifer instead which also works great. A more humid environment reduces transpiration from the leaves and keeps your tropical in origin orchid healthy.
Two More Things Worth Knowing
Skip the ice cubes. There is popular advice that states you should water your orchids with 3 ice cubes per week. Do not do this as it phalaenopsis orchids are tropical epiphytes and direct contact with ice can freeze burn the roots. Also the ice cubes often melt and water the potting medium unevenly which results in underwatering.
Use a transparent pot and don’t water on a schedule. The best habit you can build is to check the rot colour through the transparent plastic pot ather than watering on a set schedule as grey’ silver roots mean its time to water and green roots means the orchid is nice and healthy and you need to wait until the roots turn silvery before watering again. This strikes the perfect balance of watering. Once you can read the roots you can answer the question is my orchid overwatered or under watered.