The spindly tomato plant outside the sitting room window has several flowers open and a mass of new buds on the way.  It seems unlikely that all these buds will develop into fruit but, for the moment, the prospects look good.

Any pollinating insects in the neighbourhood are probably busy on the cherry trees at present, so I’ve been looking up pollination of tomatoes.  It seems that tomatoes are self fertile but not reliably self pollinating.  The pollen needs to be shaken from the inner face of the anthers onto the stigma, which may or may not stick up above the stamens.   The amount of pollen reaching the stigma affects the number of seeds set, which in turn determines the amount of flesh in the fruit.  A stiff breeze may be all that’s needed but the most reliable pollinators are bumble bees.

Unlike flowers adapted to encourage the bee to crawl inside, the pollen isn’t transferred by the furry back of the bee.  While the bee is happily sucking up nectar from a tomato flower it is the vibrations of its buzz that shake the pollen loose.  Some pollen will fall directly onto the stigma, some onto the furry belly of the bee, to be rubbed off onto the stigma of the next flower it visits.

In the absence of wind or bees, growers of greenhouse tomatoes used to send round human pollinators to gently shake the flowers, before discovering the benefits of tickling the plants with an electric toothbrush.  More recently, large scale growers have realised that it makes more sense to bring in bumble bees.  That’s not really an option with my one plant; I’ll just have to tickle it.