In the summer, we get a lot of questions as to why a vigorous tomato plant does not have any fruit on it. The blossoms drop off right at the “elbow” above the bloom. A few different factors can cause this:
- Extreme temperature swings – Having 20-degree + temperature swings from one day to another can cause this. Obviously, this is out of our control.
- Lack of calcium, lack of fertilizer, or wrong fertilizer – have you fertilized? Maybe you did when you first planted, but it might be time to reapply! Check the package for specifications or read our recommendation for fertilizing vegetables, here.
- Avoid fertilizers with high nitrogen (the first number on the label). You can also use a supplemental spray to help blossom set.
- Lack of pollination – technically, tomatoes are self-pollinating but sometimes they need a little help. Giving the tomato support or cage a gentle shake oftentimes helps.
- Too much shade – like any fruiting plant, they need a lot of sun to produce. Generally, a minimum of 4 hours a day but 6 hours or more is better.
- Overwatering – this is generally the problem. Tomatoes, unlike other plants, need to be stressed to set fruit. Otherwise, you will have large, lush plants and little to no fruit!
This is the time of year when you may also have problems developing fruit.
Here are 2 common problems with developing fruit:
The tomato on the left is sunburned. This is caused by moving the plant or transplanting and exposing fruit to the sun that wasn’t exposed before. This tomato came from my garden and happened when I transplanted a seedling out into the garden.
The tomato on the right is Blossom End Rot. This is usually an early season problem and depending on the cause, may go away later on in the summer. It can be caused by watering too frequently, temperature swings and lack of calcium. Obviously we can’t control the weather but two of the 3 causes can be corrected! You can prevent calicium deficiency by adding Epsom salts or crushed eggshells to the hole when planting the tomato. To stop or treat blossom end rot caused by lack of calcium you can apply a calcium spray, available at The Greenery. Additionally it is best to check your watering.
How to water tomato plants
It is best to keep the leaves dry and only water the plants when they actually begin to wilt, typically every 7-10 days once established. A large plant with lots of fruit may need it every 4-5 days during a heat spell. When watering, do so thoroughly and deeply. Please note, this applies only to tomatoes in the ground. Potted tomato plants will need water more frequently but still only when wilting. However, make sure the plant is wilting in the evening, if it is wilting in the afternoon but looks okay in the evening it doesn’t need water!
For more information, watch our Tomato Seminar on YouTube from 2020!
Still not sure? Drop by and speak to one of our experts!