Kitchen Garden Forum

Hi ,
I have been having a discussion with my better half as to whether spraying the tomato flowers makes any difference to whether or not the plants set fruit. I can't see how it does but he insists that it is important to ensure the flowers set. Does anyone spray theirs and does it make a difference?

Sarah

I think that spraying was recommended as it kept up the humidity levels in the greenhouse. I never spray, but when I remember, I gently shake the blossom by gently grasping the flowering branch. Does it do any good? Well, all the flowers do set fruit. It could be coincidence of course...

It's all about agitation. Tomatoes are largely self-pollinating, but they need a little persuasion in order to set fruit. They need to be shaken. Spraying with water helps to move the flowers about. So does going through the greenhouse and shaking each flowering truss by hand, as greenhouse workers used to be encouraged to do in the old days. Now, commercial growers use bumblebees, specially bred and introduced in little cardboard hives, to maximize their fruit set. There's nothing like nature's own way, after all.

I think it is best to keep tomato foliage as dry as possible.

felixLeiter said
"Now, commercial growers use bumblebees, specially bred and introduced in little cardboard hives"
I didn't know that! This has brought a smile to my face, the thought of all those lovely bumble bees buzzing around the greenhouses!

I spray the greenhouse tomatoes (but generally not those outside). I get a very good set. I'm happy...

Does it make a difference? I can't be sure, but it is a habit which means I have to give them a bit of attention every day, and at the sae time, look for side shoots, etc.

Geoff says he thinks the foliage should be kept dry. I guess he's thinking of nasties like blight and grey mould. I don't drench them, just give them a gentle squiff from a B&Q spray bottle, and in this hot weather any water that gets on the leaves evaportes off very quickly. Come the autumn, when moulds become a problem, I will have stopped spraying because the atmosphere wll be more than humid enough.

I don't think spraying will make any difference to the tomatoes setting, but it is good for keeping red spider mite at bay.

My job from being very small was to go round the greenhouse and tap all the canes supporting the tomatoes with a stick to shake the pollen in the flowers. It is something I now do automatically whenever I go in the greenhouse, not necessarily with a stick, but just give the canes a tap.

I think the spraying of plants should be kept to misting and not spraying where Tomatoes are concerned. Misting will up the humidity without saturating everything. Misting is best achieved with a spray unit by closing right down on the nozzle and keeping the pressure high within the bottle.
I mist occasionally when the need arises and I only ever water them to the roots.
JB.

I'm in two minds about spraying the foliage too much especially during the day as I worry that somehow it might trigger blight in some way although my tomatoes are outdoors so not in such as humid environment as a greenhouse. However, although I water around the roots, I do sometimes very lightly mist them in the cool of the evening if the weather has been particularly hot, but more to refresh the leaves than to try and pollinate the flowers.