First, make sure you’ve given them enough time to set fruit. In Ireland this can sometimes require patience!
Secondly, if you’re growing tomatoes outside in Ireland (not in a Polytunnel or greenhouse) they will typically be slower to set fruit and, depending on the weather, may stubble without help.
There are other reasons for tomatoes not setting fruit, here are some reasons and solutions:
Too much energy going into the leaves. If you are growing an indeterminate tomato type (non-hush) you should ‘top’ the tomato plant by cutting off the growing point at the top of the plant. This will allow it to put more energy into the fruit. You can also carefully prune suckers and non productive leaves for the same reason.
Temperature fluctuations. This is a problem in Ireland as even after a hot summers‘ day, our nights can be cold. And high heat levels can similarly affect tomato production. If you are growing tomatoes inside try to keep them cooler on sunny days by ventilating well and putting some shade at the hottest part of the day. If you’re growing outside, you may want to consider some fleece protection at night to reduce temperature fluctuations.
High Humidity we personally havent found this to be a problem, but Ireland is a humid country and this may sometimes make pollen sticky and prevent fertilisation. Regular watering of the plant to change the relative humidity level may help.
Fertility Tomato plants need fertile soil to set fruit. Feed tomato plants with specialised tomato food weekly or fortnightly.
Pot Size If you are growing tomatoes in a container, make sure it’s big enough. Usually a minimum of 20cm diameter and even bigger for vigorous indeterminate tomato plants.
Irregular Watering Tomato plants love to be watered the same amount at the same frequency.
Too little sun Tomatoes like a good dose of full sun for at least 8 hours a day. Consider moving them if they are not getting enough sun.
Insufficient pollination Tomatoes are self pollinating as each plant has both male and female flowers. However if growing indoors, sometimes pollination fails to occur. You can help by encouraging air to flow, encouraging bees and other pollinators to the area or by gently shaking the plant to help the pollen move between the flowers.
if you’re regularly watering and feeding your plants, they are pruned and in a sunny spot, sometimes the only thing to do is wait for more favorable weather!
Check out our top ten tomato growing tips here!