These little fellows are doing what comes naturally. Positioned indoors besides a window, they grow towards the light. For them light is everything, for with light, comes photosynthesis and from photosynthesis, energy. The name for this response – phototropism.
If they were outdoors and the light falling evenly on them from overhead they would be headed straight up, no stretching required. Conventional wisdom would have me turn them round so they ‘straighten up’ by bending back the other way. Indeed last year I spun my young tomatoes so frequently they must have thought life a veritable carousel.
It would seem there are downsides to this approach – all to do with the plant hormone, Auxin. Auxin stimulates an increase in the length of plant cells.
Auxin is present on the shaded side of a stem and so its presence and effect is to cause the shaded side of the plant stem to elongate. If the plant is then turned round, to face the other way, Auxin will move across to the ‘new’ shady side causing that side of the stem to become elongated as well.
All of which will result in an elongated stem and we all know what we desire in a tomato plant is not leggy but stocky, sturdy even ….
I think it’s time to get out the silver foil and create a dazzling screen with which to reflect back all that light, so that no plant of mine shall start out on the shady side of life.
(A quick PS - there’s going to be an unexpected break in TL blogging and so I’ll be back here in just over a week.)