Hydroponic Broccoli in NFT- Seed to Harvest

Last updated on October 25th, 2022 at 11:30 am

An Introduction to Broccoli

Hydroponic Broccoli (Botanical name- Brassica Oleracea) is a cool season crop and doesn’t tolerate heat well. It is a cole crop (Brassicaceae family) closely related to Cauliflower, Cabbage, Brussel Sprouts, etc. It requires temperature of around 5-28 degrees Celsius to grow. Seeds will sometimes germinate in temperatures as low as 5 degrees Celsius but warmer temperatures speed up the process. Broccoli plants need full sunlight (6-9 hours) for best growth

Broccoli is rich in many vitamins and minerals such as Vitamin A, Potassium, Folic Acid, Iron, etc. and also rich in Fiber and Protein. It can be eaten fresh, or used in soups, pasta, etc. Hydroponic Broccoli is even more nutrient rich as compared to broccoli grown in poorly managed farms or soil.

Hydroponic Broccoli Grow Time

Hydroponic Broccoli in NFT usually takes around 80-100 days from seed to harvest depending upon various factors such as temperature, how well is hydroponic system maintained and whether or not an effective hydroponic nutrient solution recipe for broccoli is being followed or not, temperature of nutrient solution, pH and many other factors.

Seed Sowing

To start nursery and raise broccoli seedlings, first we need seeds and we should always choose high quality seeds which offer highest germination rates and robust plants later on because you can’t just wait endlessly to watch low quality seeds sprout because let me tell you-they never will . Even if they do, quality won’t be as good. I used Syngenta’s “Besty” broccoli seeds here and it’s a very good seed company.

Before we sow seeds, our seed starting media should be ready as in my case I am using cocopeat which is thoroughly washed to reduce it’s salt content because let’s be honest, who likes too much salt? Uggh! and when you are buying cocopeat online if possible go for buffered cocopeat.

1. I used propagation tray for seed germination and filled the cells with cocopeat just a little bit below the rim
2. I sowed 2 seeds per cell just to ensure enough germination
3. Place the seeds on top of cocopeat and cover them lightly with same media which is cocopeat
4. Make sure seeds are not buried deeper than 1/4 or 1/2 inch
5. Cocopeat I used was very wet so I didn’t need to water it but if your cocopeat is not so wet then you can water it with low TDS water (Below 150 ppm)

Hydroponic Broccoli Seedling Stage

So, depending upon temperature broccoli seeds can take 3-6 days to germinate. I saw seeds sprouting on Day 5 where I could see little seedlings trying to break out and by Day 7 most of seedlings had emerged

I usually feed plain RO water and don’t start any nutrition until seedlings have completely emerged and their cotlyledons (first pair of leaves) are completely opened up. At Day 7 or 8 seedlings were ready for their first nutrition feed and a low strength hydroponic nutrient solution for broccoli was required, ideally around 250 ppm with pH between 5.5-6.5

You can measure TDS or EC with the help of a TDS/EC meter and pH with the help of pH meter

I bottom feed the seedlings where I place propagation tray in a bigger container with nutrient solution with level that covers propagation tray 1/4 from bottom and solution is sucked from holes at the bottom of Pro-tray.

Once nutrient solution is absorbed by growing media, propagation tray can be removed from container. One sign that hydroponic nutrient solution has been absorbed by seed starting media i.e. cocopeat, it’s colour turns dark brown as compared to light brown when it’s going to dry up.

I increase strength of hydroponic nutrient solution for broccoli seedlings is increased by approximately 100 ppm every week because there is no point in giving more than what seedlings can handle. Excess nutrients can burn the seedlings

I keep increasing TDS or strength of nutrient solution every week until transplant and never go higher than 450 ppm before transplant. At this stage, usually around 24-30 days from seed sowing, seedlings are ready to be transplanted

Transplanting Seedlings of Hydroponic Broccoli in NFT

At the time of transplanting, utmost care needs to be taken so that seedlings are not harmed. It is quite easy to remove a seedling from propagation tray as all seedlings have their separate cells, you just need to push a little bit from bottom of the cell and seedling comes out along with growing media

Also, before you transplant a seedling in NFT or DFT system you need to clean the roots and remove as much cocopeat as possible because if it gets into the NFT system then it can block the pipes or harm water pump. I usually clean the roots by first gently shaking the seedlings so that excess cocopeat falls off and then washing the roots with tap water to remove remaining cocopeat

Growing Media for Broccoli Seedlings

After washing the roots, you need to choose growing media and how you would like to put your seedlings into NFT system with proper support. I used 3 inch net cups for this purpose along with glass marbles for support. Although glass marbles are heavy but since I didn’t have any other option at that time and they were readily available so I used them

You can use any growing media such as Clay pebbles (hydrotons), Foam blocks, Perlite, etc. and the only thing you need to keep in mind is that growing media should not be able to affect ph of nutrient solution otherwise your pH will always be out of whack

To put seedling in net cups, put the roots first so that comes out hanging from the bottom of net cup and have access to hydroponic nutrient solution

A Glance at NFT system for Hydroponic Broccoli

I grew Broccoli in NFT (Nutrient Film Technique) or to be more precise DFT system (Deep Flow Technique). The difference between the two is that NFT has very shallow stream of nutrient solution flowing where roots are always in touch whereas in DFT there is a depth of 1-3 inches of nutrient solution hence the name Deep Flow Technique but hobby gardeners often use both terms inter as interchangeable

Here’s a look at my NFT system……

I had one spare 10 feet uPVC pipe, so I cut in half to make two pipes and drilled 8 holes in each pipe 6 inch distance to fit 3 inch net cups. You can click here for the tool kit including drill bits or hole saw that is required for all this drilling. I used an Iron angle stand to place the pipes and fastened them with metal clips you can easily get in a hardware store

For re-circulation of hydroponic nutrient solution, I installed a drip irrigation pipe system where a submersible pump in the reservoir was connected with 16 mm main supply line to carry the nutrient solution around with 4 mm feeder lines inserted in the 16 mm main pipe near the input holes in the pipes

Also, return of nutrient solution back to the reservoir was facilitated by using 1 inch PVC pipes attached at one end of the 4 inch pipes by drilling a hole in End caps

Let’s take a look at how the nutrient solution is being supplied and also at depth of the solution inside the pipes

Now, it’s time to transplant our seedlings into NFT system. Earlier we had put seedlings in 3 inch net cups with marbles in it. All I had to do was to put each net cup in the holes and that’s all about transplanting broccoli seedlings in NFT system

Note how the roots are touching nutrient solution. When they touch the solution, it gives signal to plants that there’s nutrients and water below and eventually plants grow more roots to absorb more nutrients from the solution. I keep the solution level in pipe at least half inch below net cup bottom in order to ensure enough aeration for plant root zone. If nutrient solution in NFT pipes touch the bottom of net cups then chances of root rot or drowning are higher due to lack of aeration

Hydroponic Nutrient Solution Recipe for Broccoli

Nutrition is very important in Hydroponics where plants are dependent on us for their needs and therefore, it is very crucial that we provide optimum nutrition to our plants.

I used the same Hydroponic nutrient solution recipe for broccoli that I use for other Fruiting vegetables such as Hydroponic Bottle Gourd. It gives fantastic results. You can click the links to read more about Nutrient solution recipe

Below you can see growth updates of Hydroponic Broccoli along with changes in Nutrient Solution strength –

Hydroponic Broccoli EC or TDS and pH details

Strength of nutrient solution is increased by around 150-200 ppm every 7-10 days from here on so that growing plants get all the nutrition that is required for healthy growth. Always increase strength of nutrient solution gradually otherwise plants can get burnt due to excess nutrition. Full strength nutrient solution has TDS of around 1200-1300 ppm or EC 2.4-2.6 mS/cm

pH of Hydroponic Nutrient Solution is always kept between 5.5-6.5 for optimum nutrient uptake

Hydroponic Nutrient Solution was changed completely every 10 days along with increase in TDS as per plant growth. Leftover solution was either fed to plants in soil or discarded off

Harvesting Hydroponic Broccoli in NFT

At Day 75, Hydroponic Broccoli was ready to be harvested. Broccoli head should be harvested in the morning when it is firm and tight. The size of broccoli head also depends on the variety you are growing but when the head is big enough for a large size fist is also firm and tight without loosening of the curd then it’s right time to harvest it.

Broccoli Head is actually its flowers before blooming and if you don’t harvest broccoli at the right time the the head will loosen and you will see flowers forming. If you see yellowish leaves starting to form in broccoli head then you’re probable late and should harvest broccoli right away or it won’t taste as good

Cut the heads from stem with 1-3 inches of stem attached to broccoli. Once harvested it should keep well in refrigerator for 4-5 days and it can also be blanched and frozen for a year. After harvesting, tiny heads of broccoli will keep forming for couple of weeks/months which you can harvest

You can also watch my video on How to grow Hydroponic Broccoli in NFT by clicking the link below :-

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