Auxins, geotropism & upside down tomatoes

green-tomatoes-stunt-action-upside-down-shotI may be a little obsessive but tomatoes are on my mind again…

Upside-down tomato plant hanging contraptions have been hanging around for years and I’m a bit skeptical. bit skeptical. I’ve heard lots of people marvel over them but I’ve not seen a pic of the plants actually growing in them. The only pics I’ve seen have clearly been taken for advertising purposes when the plants are in full fruit. Do upside down tomato plants work?

My heart always goes “Oooo, that looks nice”. But my head goes, “but what about the auxins?” Auxins are hormones that control aspects of plant growth – things like the flowering, fruiting, bulb formation, dormancy etc.

More on auxins after the jump, along with links to how to test these mad ramblings…

The Auxin Dilemma in Hanging Tomato Plants

Auxins move through plants in only one direction – from the tip of the shoot down. That’s why your cuttings won’t grow if you plant them upside down. Roots grow in response to high concentrations of auxin which accumulate at the bottom of the plant. This is why rooting compound works. Auxins are responsible for phototropism (where plants respond to light) and geotropism (where plants respond to gravity).

I’ve never seen one  of these upside-down tomato planters in action. And I’ve not wanted to fork out for one to prove my hypothesis, even if it is only $19.99 with free knives. If I do get inclined for a weekend project though, the Cheap Vegetable Gardener has a nice little how to build your own planter.

If anyone has evidence or mere conjecture either way, please let me know through the comments.

Comments

  1. Friends of our grow them by the back door. Just a cheap hanging planter with a tomato seedling planted upsidedown through a hole cut in the bottom. It looks great, and crops really well — the kids just grab tomatoes on the way in and out of the house.

  2. Tomatos says:

    Yes, auxins move from tips to shoots, but rely on a unidirectional transport called polar transport. It has nothing to do with gravity! Concentrated at the base end of a cell, the auxin transporters move the hormone out of the cell, so it can enter the apical (tip) end of the neighboring cell.

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