A Beginners Guide to Growing Tomatoes Hydroponically in Home

Last Updated on January 10, 2019

Just imagine the first bite of a fresh, sweet tomato picked from your own hydroponic garden. That warm juice rolling down your chin soothes like nothing else. So, how about growing hydroponic tomatoes at home? Well, hydroponic tomatoes unlike their soil-grown counterparts are superior and can be enjoyed all year long. Not only this, they have a perfect appearance, firm flesh, tender skin, and delightful flavor and aroma.

Hydroponic Tomatoes

Hydroponics is a very efficient and popular way to grow several vegetables due to numerous advantages. Hydroponic systems allow plant production in a water, which has essential plant nutrients dissolved in it. You can grow plants in a controlled environment – without insects, weeds or soil-borne diseases. Moreover, these hydroponic tomato plants grow faster and have a high yield.

Botanical Name:Lycopersicon Esculentum
Optimal Temperature:Day: 22–26 °C (70-79 °F)
Night: 3-18 °C (58-65 °F)
pH:5.5 - 6.5
Germination time & temperature:4–6 days; 20–30 °C
Growth Time:65 to 120 days after Planting (Varies in Varieties)
Plant Spacing:40-60 cm (3–5 plants/m²)
Plant height & width:60–180 cm; 60–80 cm

Growing Conditions for Tomatoes

1. Temperature

Tomatoes prefer warm temperatures ranging between 70 and 79 degrees Fahrenheit ( 21 – 26 °C) with full sun exposure. The night temperatures of 13-18 °C (58-65 degrees Fahrenheit) encourage the fruit set. The plants stop growing below 8-10 °C and the temperatures above 32 °C (90 degrees) cause floral abortion and poor fruit setting. Moreover, humidity should vary between 40% – 50%.

2. Hydroponic Nutrients

Most of the varieties of tomatoes require a high level of nutrients like potassium and phosphorous. It also requires calcium supplement and other hydroponic nutrients for successful growth. The hydroponic nutrients for tomatoes include Calcium Nitrate – Ca(NO3)2, Potassium Nitrate – KNO3, Sulfate of Potash – K2SO4, Monopotassium Phosphate – KH2PO₄, and Magnesium Sulfate – MgSO₄ * 7H2O. The tomatoes also need around 54 elements in traces that include Iron – Fe, Manganese – Mn, Zinc – Zn, Copper – Cu, Boron – B, and Molybdenum – Mo.

A higher nitrogen concentration is preferable during early stages to favor plants’ vegetative growth; however, potassium should be present from the flowering stage to favor fruit settings and growth. Moreover, the tomato plant is grown well with a pH level between 5.5 and 6.5.

Basic nutrients will only give you 12-16 elements. You can also foliar spray your plants to enhance nutrient uptake. Ocean Solution provides around 90 elements and the plants take what needs even at the micro level.

3. Light

Tomatoes require a lot of lighting but can thrive with at least 7 hours of sunlight/day. But make sure to safeguard plants from very strong rays of the sun as it may cause heat stress. At maturity, the plant requires 8 hour respiration period of darkness and 16 to 18 hours of photo-period for maximum fruit production. You can use LED grow lights to grow tomatoes indoors.

4. Water and Aeration

Make arrangements for air systems like air pumps for the plant to thrive. Similarly, water supplied to the crop must be pure. Deeply study how the presence of certain minerals can affect plant growth before supplying water to it. Tomatoes have a moderate tolerance to salinity, which makes them suitable for areas where pure freshwater is not available. Higher salinity at fruiting stage improves the quality of the products.

Best Hydroponic Tomato Varieties

Tomatoes can be classified into thousands of varieties by their size, shape, color, taste, harvest time and purpose (pickling, slicing or sauce).

best hydroponics tomato variety

You can find tomatoes in different colors including orange, red (Picolino), plum (Flavorino), yellow, cream, pink, white, purple to black, green, and zebra-striped multi-colors. Currant tomato is the smallest variety. Tomatoes also vary by when they can be harvested: early season (from 40-60 days); midseason (60-80 days); and late season (80 or more days). Some tomatoes are picked green and ripened indoors.

So what is the best variety for hydroponics?

Every tomato variety will do good in hydroponics, but you should choose on the basis of several other factors. Large commercial hydroponics farms usually prefer smaller sized fruit (cherry and grape) while the beefsteak varieties (Quest, Trust, Match, Geronimo, Blitz) are the fruit of choice for the small growers.

If you are growing indoor and can control the temperature, you should choose an indeterminate tomato variety. These vine-like tomato plants grow, ripen fruit and set new ones all at the same time throughout the season indefinitely until killed by frost. Without any pruning, they can reach up to 12-14 feet. Most of these varieties rely on staking or trellis for support.

If you are growing in an outdoor system, use seasonal determinate tomato varieties that usually grow as bushes. These require the least amount of space and can be grown in a small-sized garden or in containers.

Moreover, Choose your plants based on 

  • Length of your growing season (early, main crop, or late harvest)
  • Size of the plant you can accommodate in your hydroponic system
  • Want to stake or cage the plant or let it sprawl?
  • How you plan to use the harvest? eating raw, cooking, pickling, canning, or drying. The cherry and beefsteak tomatoes are great for eating fresh.

Hydroponics Tomatoes Setup

For hydroponic gardening of tomatoes, the following components are must-have to set up a system.

  • A reservoir filled with a nutrient solution.
  • Nutrient pump and air pump to supply nutrients and air respectively to the plant roots.
  • Another requirement is of growing media which holds roots and channelize water and nutrients to them. If you are using soil-less mix such as perlite and peat, then there’s no need to supply nutrients during initial stages, and fresh water is just enough. However, while using an inert medium such as Rockwool, make sure to feed nutrients in all stages.

Hydroponics is a clean cultivation technique. It’s recommended to plant tomatoes directly from seeds as plants brought from outside are easily susceptible to pests and diseases. Start the process by placing seeds in Rockwool starter cubes in a domed nursery tray. Before planting, these Rockwool cubes should be soaked in water (with pH of 4.5). Keep tray covered in a moist and warm environment (20-25 degree Celsius) until the seeds begin to sprout. Once seeds start sprouting immediately remove the domes and place seedlings in a light source for at least 12 hours a day. After roots appear at bottom of these starter cubes, transplant it to the hydroponic garden. There are many systems available, choose the right hydroponic system for tomato cultivation.

Following methods of hydroponics are commonly used to grow tomatoes.

1. Deep Water Culture DWC

Deep Water Culture Hydroponics

DWC Hydroponics systems work well for growing tomato plants. In this system, plants are placed in a net pot fitted in the reservoir with the roots submerged in the nutrient solution. An air pump oxygenates the water constantly to ensure roots get an adequate amount of oxygen. Read more about setting up the system to grow tomatoes in the ultimate guide to DWC hydroponics here.

2. Kratky Method

This is the variation of Deep Water Culture and most basic form of hydroponics that use no electrical equipment. You just need a bucket with net pot and nutrient solution to get started. You leave an air gap to expose some parts of roots to the air for oxygen while the other parts are submerged in the waters to get nutrients. This method is not efficient for tomatoes. As you will need more regular checking to ensure the water and nutrient levels.

3. Dutch Bucket Hydroponic

Dutch Bucket hydroponics Tomatoes

One of the common methods used for tomato plantation is Dutch Bucket that is a variation of the Flood & Drain hydroponic method. In this, the nutrient solution is pumped from the reservoir through a pump and fed to plant roots through drip emitters and then drained back to the reservoir. The starter cube is placed in a premade hole of a 3 or 4 inches Rockwool cube, which in turn is placed on Rockwool slabs in a trough. Plant roots will grow down into the slabs through those cubes.

Dutch buckets (Also known as Bato Buckets) are especially used for tomatoes and other vining crops like cucumbers. Tomato plants can be trained vertically upward to create a tower of plants that are easy to monitor and harvest.

Check other appropriate hydroponics methods and how they work. Also, check Aeogarden hydroponic indoor kits to grow tomatoes easily and automatically.

Hydroponic Tomatoes Nutrient Solution

Following is the best hydroponics fertilizer for tomatoes available in the market.

Tomato Fertilizer 4-18-38 Powder

Hydroponic Tomato Fertilizer 4-18-38

It is completely soluble in water without much need of mixing. It has Nitrogen, Phosphorous, Potassium, Boron, Iron, Zinc and other trace elements required by tomatoes. The durable and resealable bag is designed to stand up without tipping or ripping. Growers have a great success with growing tomatoes as well as bell peppers, lettuce, cucumbers, and flowers with this as a base for hand mixed nutrients. Click here to check Price.

Planting & Care Instructions

  • Set stakes or plant support structures before transplanting to prevent root damage.
  • Remember to take wider trough than the slabs; also there should be 4 plants per slab.
  • Plant both indeterminate and determinate tomatoes as well as early and late cultivars to allow for a continuous and staggered harvest.
  • Transplant the seedlings into units 3–6 weeks after germination when the seedling is 10–15 cm and when night-time temperatures are constantly above 10 °C.
  • In transplanting the seedlings, avoid waterlogged conditions around the plant collar to reduce any risks of diseases.
  • Size of the pump and reservoir will depend upon the number of plants taken. Choose the pump with high gallons/hour rating so that plants farthest from the reservoir equally receive the nutrient solution.
  • Once the tomato plants are about 60 cm tall, start to determine the growing method (bush or single stem) by pruning the unnecessary upper branches.
  • Remove the leaves from the bottom 30 cm of the main stem to favor a better air circulation and reduce fungal incidence.
  • To favor fruit growth, Grow the plants with a single stem (double in case of high plant vigor) by pruning all the auxiliary suckers.
  • Fill the reservoir with the fresh nutrient solution every week. Irrigation needs to be adjusted as the plant grows. Mature plants will consume about 4 liters of nutrient solution every day, while seeds will need less water.
  • Carefully clean emitters for proper functioning, as they can be clogged over time.
  • Adjusting pH levels is necessary. pH of the solution indicates acidity and alkalinity of a nutrient solution. If appropriate pH balance is not maintained, the plant may suffer from various nutrient deficiencies or toxicities.
  • Remove the leaves covering each fruiting branch soon before ripening to favor nutrition flow to the fruits and to accelerate maturation.
  • If you are growing tomatoes indoors, you will need to hand pollinate to assist the flowers to produce fruit.
  • Foliar sprays of compost tea on tomatoes help prevent plant diseases and certain nutrient-related problems.

Harvesting

For best flavor, harvest tomatoes when they are firm and fully colored. Fruits will continue to ripen if picked half ripe and brought indoors. Fruits can be easily maintained for 2–4 weeks at 5–7 °C under 85–90 percent relative humidity.

Accessories for Growing Hydroponics Tomato

Hydrofarm GCTR Tomato Trellis Garden on Wheels although not a soil-less hydroponic system, it’s probably the closest a lazy home gardener can get to feeding/water the plants via a water reservoir. You can convert into DWC system through some modification.

Vivosun grow tents offer the best value for grow tents to grow tomatoes indoors. Check full review about Vivosun grow tents here.


Although hydroponic gardening seems to trickier, once it’s practiced using proper knowledge and tools it can yield great results. So, create a hydroponic kitchen garden and enjoy fresh, juicy ‘homegrown tomatoes’ all the year round.

Related Post

Leave a comment

Your email address will not be published. Required fields are marked *