Tomato fruit not setting

[Opal]

For the third year running I'm having problems with my tomatoes.
The problem I have is that although there are abundant flowers, they don't set fruit. I feed them every week and they are growing in a poly-tunnel. At first I thought the soil might not be good, so I planted them in a grow-bag placed in the tunnel, but the problem seems to be the same.
Can anyone tell me why this is happening?
Thank you

[rustylady]

Do you keep the tunnel open so insects can get in? Or tap the plants to release the pollen?

[Alison]

Tomatoes are self pollinating but they will fail to set fruit if they are too hot or dry etc. Try and increasing the humidity as that can help, easiest way of doing this is by leaving a couple of buckets of water locally to the plants.

[Lurch]

You could aways try give them a helping hand and pollinate them with a brush?

[solway cropper]

I use a cotton bud. Just dab the flowers with it and move on to the next plant. Don't know if it's that or the insects but I get a bumper crop in the greenhouse....and they've been great in my sarnies.

[terrier]

As Alison said, they are self pollinating, they don't need the insects. You could try misting the plants to get the humidity up. In a greenhouse, you can remove panes of glass to give more ventilation to get the temperature down on very hot days. If they get too hot they won't set. You could try a fan in the tunnel to keep the air moving?

[Flummery]

I tend to swill my greenhouse path (flagstones down the middle) with water in a hot dry day - just to keep up the humidity as it evaporates. I don't have problems with set and have NEVER tickled up a tom!

[maytreefrannie]

I think the flowers show quite a bit before the fruit sets - my outdoors are in flower for a number of weeks now and no fruit yet, but the indoor cordon ones were the same - they're just now starting to fruit.

Remembering other years, I think the same thing applied. If on the other years you were growing the tomatoes outdoors, could it have been that they flowered late and afterwards didn't get enough sunshine to fruit? If so, your g/h crop are in good time this year.

[SMS6]

Poor tomato fruit set takes place for many reasons. Prime among them are the occurence of extreme temperatures. When tomato plants experience extreme temperatures, either below 55° or above 90° F, for an extended period of time it may cause developing tomato blossoms to drop off. These blossoms drop off before the tomato fruits can set and therefore the tomato fruits do not develop. Another cause of poor fruit set in tomato plants is excessive nitrogen composition in the surrounding soil of the tomato garden. When the soil around tomato plants has a high nitrogen concentration, this promotes lush leaf growth to the detriment of tomato blossom and tomato fruit formation. Excessive nitrogen is the most common cause of lush foliage with no tomato fruits in the garden. Shading may also account for poor tomato fruit set. Be sure to locate your tomato garden where it will receive no less than six hours of sunlight per day. If the number of hours your tomato plants receive direct sunlight drops below six, it could be the cause of poor fruit set. The last, and often overlooked, cause of poor fruit set in tomato plants is very simply, dry soil. If your tomato plants are not receiving adequate water for their nourishment needs, tomato blossoms will dry and fall off plants.


What can you do about it?


When planting your tomato garden, be sure to place it in an area that receives at least six hours of sunlight per day. Make sure the area you choose for your tomato plants does not receive too much shade from other plants, trees, or structures in the area. Correct any nitrogen imbalance in the soil by using a fertilizer which is rated 0-10-10 or 0-20-0, applying the fertiler according to package label instructions. Also be sure to keep tomato plants watered. This means a regular schedule of watering which prevents the soil from drying out too much at any one time. You can also mulch your tomato plants in the vegetable garden with straw, black plastic or other mulching materials to improve the moisture of soil surrounding the tomato plants. Additionally, when you are planting your tomato plants, plant them at the appropriate time of the year. Pay attention to the seed packet or tomato transplant instruction and note whether the varieties you have chosen should be planted early, mid or late-season.