Hydroponic Tomatoes are one of the most versatile fruits, allowing you to use them in salads, pasta sauces, or even ketchup. However, not everyone has the soil and garden space to grow them normally. If you’ve been looking for information on how to grow hydroponic tomatoes, you’ve come to the right place.
This guide covers everything from the necessary nutrient mix to pH level and lighting for growing hydroponic tomatoes. We also discuss upkeep and which tomato varieties work best in a hydroponic system.
How to Grow Hydroponic Tomatoes
There are a few factors to consider when setting up your tomato hydroponic system to grow hydroponic tomatoes.
- pH level: Ideally, you should aim for a pH level between 5.5 and 6.5. You can reduce pH by adding citric acid, vinegar, phosphoric acid, or pH down to your growing solution. If the pH is too low, you can bring it up with pH up, potassium carbonate, or potassium hydroxide.
- EC level: You want an electrical conductivity rating of between 2.0 and 3.5. If your EC level is too low, you can increase the conductivity by adding more nutrient solutions. If it is too high, add more water to dilute it.
- Temperature: The ideal growing temperature is between 64 and 77℉ (18 and 25℃). You may like to keep the temperature constant by using a grow tent.
- Life cycle: Tomatoes can take up to 10 days to germinate, up to 6 weeks before you can transplant, and a total of 2 months after that before setting fruit.
Tomatoes are pretty durable. Therefore, you can use them with most hydroponics systems, including:
- Nutrient Film Technique: This hydroponics system is popular with commercial hydroponic tomato growers. It can help tomatoes grow well, but some plants further down may receive fewer nutrients. You will need to monitor your crops carefully if you choose this setup.
- Ebb and Flow: This system is simple, easy, and preferred by many home growers of tomatoes. However, it makes it challenging to control nutrient distribution. Therefore, more intermediate growers may like a different option.
- Drip: Drip systems let you control nutrient levels more effectively for individual plants. If you have the expertise and the time to put into your hydroponic tomato crops, this could be a worthwhile setup.
- Deep Flow Technique: This system can be more productive in some tomato growing conditions. Because the roots always have access to water and nutrients, they tend to give a higher yield.
You should optimize your nutrient levels for your hydroponic tomato crops. You can use this table as a guideline.
|Minimum level (meq/l)
|Maximum level (meq/l)
Tomato plants need between 8 and 16 hours of light every day to grow properly. If you are growing your crops inside, you may need to set up some LEDs as a light source.
Rather than choosing household light bulbs, opt for grow lights. These specialized units can cover the full-color range and run for many hours continuously when needed by your plants.
There are a few steps to the growing process of hydroponic tomatoes.
- First, you will need to sprout your seeds. We don’t recommend using seedlings because they can carry contaminants and pests from the soil and outdoor environment. Grow the seeds from scratch in Rockwell cubes until they sprout.
- Move the sprouted seeds into your hydroponic system. It could take up to two weeks for them to fully integrate.
- Water your plants adequately every day. Depending on the hydroponic system you use, there are different ways to control this. However, a mature tomato plant needs approximately 4L every day, while a small plant needs less.
- Pollinate your flowers. Once your tomatoes grow flowers, you will need to pollinate them. You can use a fan to blow the pollen around, imitating the wind. Alternatively, you can use a soft paintbrush to transfer pollen between plants.
- Prune your tomato plants. You will need to prune leaves as the plants grow to direct nutrients to the fruit. You can remove any shoots that grow beneath the flowers. You should also cut off side shoots and wilting leaves, allowing your main shoots to bear the best fruit.
- Do ongoing maintenance. You should change your nutrient system approximately once a week. When you do this, you can also rinse accumulated salts and minerals off of your plant roots. Whenever you do maintenance, make sure to check pH and EC levels afterward to see that they are ideal.
- Harvest your tomatoes. Most tomatoes are fully grown in 2-3 months. You will know that they are ready to harvest when they are entirely red with no green sections. You can also squeeze them to test the firmness. Remove the tomatoes by twisting them off the vine.
Which Tomatoes Grow Best in a Hydroponic System?
There are countless varieties of tomatoes. However, there are several kinds that do best in hydroponic systems:
- Cherry tomatoes: Cherry and other miniature varieties grow well in hydroponic systems. They require a little more work and may have lower yields, but they have a unique taste.
- Beefsteak tomatoes: This is one of the most popular options in hydroponic systems worldwide. This variety is resistant to some molds, has an excellent texture, and you can grow it as a short or long-term crop.
- Heirloom tomatoes: Heirloom tomatoes are not as productive or resistant as Beefsteak varieties. However, some types like ‘Moskvich’ and ‘Thessaloniki’ perform very well in hydroponic systems.
- Specialty tomatoes: Some plum and Italian tomatoes are gaining popularity for hydroponic growers. They tend to yield high-quality fruit. However, they are sensitive to rot in warmer climates.
In conclusion, tomatoes are one of the most rewarding crops to grow in a hydroponic system. They are hardy and can withstand a range of growing conditions. However, by optimizing all of the growth factors, you can get the healthiest and most delicious fruits.