More orchids are killed by over watering than for any other reason. It begs the question, how much water do they really need? How long can an orchid go without water?
I know they grow slowly and react slowly to their environment. They also die slowly. I decided to see if an orchid needs to be watered regularly.
Orchids – Testing Their Water Needs
I decided to take one of my phalaenopsis and use it for this test. I took the plant out of its pot on 7/17/2015 and took all of potting media off the roots. The orchid had been in arborist wood chips – I wanted to see how well these worked as a medium. You can see from the pictures below that the roots were not in good shape. Wood chips don’t seem to work too well for orchids.
I set the orchid on my desk and waited. It was not watered or misted during the duration of the experiment. It was fairly close to an east facing window which gave it low light.
At the 48 day mark I started feeling sorry for the poor thing especially since I was about to leave for two weeks of holiday. I put it back into a pot with coconut husk and watered it. It did not get watered again for two weeks while I was away. When I returned, it was watered whenever the media was completely dry – about once a week.
For more about my watering technique see, Watering Orchids with Ice Cubes
The picture at the top of the post shows the orchid at the start of the experiment. The top leaves look quite turgid and it is growing a new leaf which is always a good sign.
The above picture shows a closeup of the roots at the start of the experiment. You can see that quite a few of the roots are rotting – they are the black ones. If left in the pot with the wood chips, further rot would have occurred and it would have started to have a water stress even in the pot. Even with such a poor root system there were no obvious signs of stress showing on the leaves.
After 24 days without water the orchid is starting to show signs of stress. The top three leaves still look turgid and the new leaf is still growing. However, the lower two leaves are starting to show wrinkles, a sure sign of water stress. It is normal for the phalaenopsis to start loosing the lowest leaf – they rarely have more than 4 leaves when grown in the home.
The green tips on the gray-white roots show that the good roots are growing. These seem quite healthy and are being used to pick up moisture from the air.
It is now 48 days without watering. All the leaves are showing water stress and the lower leaf has gone brown, allowing the plant to absorb its water. Even the good roots are now wrinkling as a result of inadequate water.
Even though there is some stress, the plant is perfectly healthy and very much alive.
At the 48 day mark the orchid was put back into a pot; this time with coconut chunks. It is a medium I am quite familiar with and know it works well for orchids. At 94 days the plant is growing well and the leaves have full turgor. The newest leaf is a good size which shows that the orchid did not encounter too much stress while it was growing.
For more about potting orchids see, Repotting Orchids
Orchids – Do They Need Water?
This orchid was not watered for almost 7 weeks. Over that time it slowly lost water, which can be seen by the wrinkling in the leaves, but it did not undergo extreme stress.
Clearly, you can leave an orchid for a couple of months without watering and it will survive. I don’t recommend this, but missing a couple of waterings will not kill an orchid.
It also shows how tough orchids really are. The only real way to kill them is with too much kindness. Be mean to your orchids – they will love you for it!