First, what is the permanent wilting point or PWP? And is my houseplant at that point?
The Permanent Wilting Point is the point at which your plant has wilted and is staying that way permanently. Okay, that is my definition, but the scientific definition is almost the same. It is the point at which your plant does not have enough moisture in its potting medium to sustain it, its roots have died, and it can no longer live.
As you can see in the pictures below, my fittonia has wilted. If you have ever owned a fittonia, you know they are quite dramatic and wilt easily. Fittonias prefer to have moist potting medium at all times. The good thing is, they do bounce back. Unless…….they are at the permanent wilting point, in which case they will not recover. Thankfully, I caught it in time and gave it water.
Below is a time-lapse I did of my ‘Jurassic Pink Shades’ Rex begonia reviving from wilting. I went away for the weekend and it was hot. With the air turned up, the heat, and lack of enough water, it wilted. It is also on the second floor of my home and I talk about how second-floor plants may need different treatment here.
How will you know if your plant is at that permanent wilting point? If your plant wilts, you water it, and the leaves don’t rise back up, you know your plant is probably done. The roots were too desiccated to recover and take up water for the plant. Your plant will remain wilted and the potting medium will stay wet as the plant can no longer take up the water. Some may assume they didn’t give it enough water if it stays wilted and give it more. That won’t work as the roots are compromised.
The consequence of the above video is yellowing leaves and I will remove them. But, I am glad that this plant wasn’t at the PWP, or it would be dead instead of having a few yellow leaves.
Another plant we probably have all watched wilt is the peace lily or Spathiphyllum lily. Some people actually use that indicator as their cue to water the plant. Not the best pracice, by any means. I take care of a peace lily at our church that wilted during the covid shut down more than once. It did recover but there were a lot of yellow leaves that needed to be removed, as it was almost at the PWP when it was watered.
How to revive a dry plant
This calathea/goeppertia dried out and the potting medium pulled away from the side of the container because it was so desiccated. If it happens but your plant seems like it is still alive, place them in a container of water and let the plant draw water up and rehydrate the plant. If you click here, you can see the results of this method of reviving this dry plant.
Exception to the Rule
The exception to the rule of “all leaves dead so the plant must be dead”, is the oxalis or shamrock plant. It can dry out completely and the leaves collapse as you can see and it will come back as you can also see in the pictures. They naturally go dormant and come back. When I forget to water it, it goes into dormancy, (poor plant) and then reappears when I water it. That is probably not the best thing for the plant if it happens often, but it will come back.
I hope you catch your dry plant and water it before it reaches that permanent wilting point, or PWP. If you don’t, its okay. Sometimes these things happen, especially when you have a lot of plants, go on vacation, or it is hotter than usual.
Have a great week, plant friends and go check your plants!