The Carnivorous Plant FAQ v. 12

Q: Why do the leaves on my Venus flytrap snap shut slowly, or not at all?

A: Talk about a let-down! You get your new, vicious plant home and try to goof with the leaves, and they don't close! What is going on here?

The bad news is that you have a variety of Venus flytrap that does not snap shut. These have been genetically engineered not to close because market research has shown that people like more brightly colored plants, and they don't care about qualities like snapping leaves. This is the same reason store-bought tomatoes look so good but taste so bland, and why genetic companies are making fortunes by designing really weird corn.

No, not really.

Now for the truth.

Venus flytrap leaves can only go through the snapping-shut-and-opening routine about half a dozen times before they stop functioning as trapping leaves (more about that below). You can bet that your new, store-bought plant has been jostled, abused, and triggered by a dozen pencil-wielding humans before you brought it home. If none of the traps work anymore, you will have to wait until it makes new traps. This may take a while.

On the other hand, another reason your plant might be so sluggish is that your plant is dying. Don't e-mail me for advice on what to do---read the FAQ. I couldn't possibly diagnose your plant based on your photograph and description.

Incidentally, on very cold days traps tend to close very slowly.

Once a leaf stops functioning as a trapping leaf, it does not die. The trap stays green, but gets a funny outer-curling edge (see the photograph to the right). Many times the leaves spread wide open so the lobes are about 180° apart. The leaf now behaves like a simple, photosynthetic leaf. As long as nothing strange happens, this leaf may persist for many months. It is still providing the plant with the valuable service of making sugars by photosynthesis, so do not cut the leaf off!

I do not think that speed of trap closure correlates with the plant being "hungry." That would be cool if it were true, but I do not think it is. Dang!

A final geeky note for you. The underlying reason that traps can only close a finite number of times, and not over and over and over, is rooted in the "acid growth" stage of leaf closure. After several closing events, the cells of the plant are as elongated and stretched as they can get. They can grow no further.

Page citations: D'Amato, P. 1998a; Rice, B.A. 2006a; Schnell, D.E. 1976.

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Revised: 2018
©Barry Rice, 2018