Hydroponic Cucumbers in Grow Bags or 5 Gallon Buckets Outdoors

Last updated on October 25th, 2022 at 11:34 am

Hydroponic Cucumbers in Grow Bags or 5 Gallon Buckets Outdoors – Cucumbers can be grown hydroponically outdoors or indoors in various hydroponic systems but in this post I am going to share how I grow Hydroponic cucumbers in substrate hydroponics, i.e 5 gallon buckets or grow bags filled with cocopeat via drain to waste method.

Although the title says grow bags but you can always use other containers such as plastic paint buckets or other containers. I have also used 20 L paint buckets for the same purpose (You’ll see in the post ahead)

Seed Starting Process

To grow cucumbers in hydroponics high quality seeds are required and therefore I chose Syngenta’s Glossy Cucumber seeds that are also used in commercial farming. Also, I normally start seeds in a propagation tray and below you can see I have all three things required to start seeds :-

• Cocopeat that is thoroughly washed to have lower salt content
• Propagation tray
• Syngenta Cucumber seeds

First, cocopeat needs to be filled in the cells of pro tray to the point that is 1/2 inch below the rim or edges of cells. Then you can sow 1-2 seeds per cell and cover the seeds with just enough cocopeat to hide them. Don’t bury cucumber seeds anymore than 1/2 to 1 inch

After covering seeds with cocopeat, you can water the propagation tray preferably with a water sprayer to make cocopeat moist or even wet. At this stage plain R.O. water or any water with EC/TDS below 0.4 ms/cm or 150-200 ppm can be used because there is no need of nutrients before germination

Keep the propagation tray in indirect sunlight until there is germination and after that move the tray to a spot having full sunlight

Germination of Cucumber seeds

Cucumber is a warm season crop and it doesn’t tolerate cold well. Best temperature range for growth of cucumber plants is between 20-30 degrees Celsius and depending upon temperatures, cucumber seeds can take anywhere between 3-5 days to germinate

Below you can see germination of cucumber seeds happening at around Day 5 after sowing the seeds

A couple days later you can see in images below both seeds had germinated and now I had to thin the seedlings in which one seedling from each cell is removed and healthiest of the two seedlings is carried on with. Thinning is done have just one seedling per cell and we sowed two seeds per cell in order to ensure enough germination in case quality of seeds is doubtful

You can just pull out the weak seedling and discard or transplant them elsewhere

Starting Hydroponic Nutrient Solution for Cucumbers

After first two leaves of the seedlings open, I start feeding them with a weak nutrient solution of strength around EC 0.5 ms/cm or TDS 250 ppm. I bottom feed the seedlings where I place the propagation tray in a bigger container filled with hydroponic nutrient solution for cucumbers and let cocopeat absorb the solution

EC or TDS can be measured with the help of a EC/TDS meter

Once cocopeat has absorbed the solution it’s color will turn to dark brown which means it’s wet now. pH for hydroponic cucumbers should always be kept between 5.5-6.5 at all stages of growth

ph can be measured with the help of a pH meter

Cucumber Seedlings usually take around 25-30 days from sowing to be ready for transplanting. Until transplant, strength of nutrient solution is increased by around by EC 0.3 ms/cm or TDS 150 ppm every 5 days or a week and is not exceeded EC 1.0 ms/cm or TDS 500 ppm mark until transplant

Transplanting Cucumbers in Grow Bags/Containers

Below you can see that at around 24 day mark seedlings were ready to be transplanted and you can transplant any seedling when first pair of true leaves in a seedling has emerged. True leaves are the second pair of leaves after cotyledons (First pair of leaves)

To transplant seedlings, I had to pull them out of propagation tray by gently pressing the cell from outside and below and then pulling the seedling out

Since I was growing cucumbers hydroponically outdoors, I chose 5 gallon paint buckets ( 20 Litres) for seedlings to be transplanted into , I had all the buckets lined up and ready with growing media already filled in them. I used 70% cocopeat and 30% perlite as growing media but you can also use 100% cocopeat if you want. Buckets had a hole at the bottom for drainage as I am growing these plants through drain to waste method where nutrient solution is not circulated

You can also use grow bags in place of these buckets, there is not much difference. I use these buckets because it’s easy to move them around and grow bags can get damaged if you try to move them but grow bags are definitely lighter in weight and compact to store. So it’s up to you what to choose!

To transplant seedlings into these buckets I had to dig a shallow hole in the center of the bucket and then place the seedling in that hole thereafter firming the media around the seedling for support

You can either hand water the plants or install a drip irrigation system if you find hand watering difficult or time consuming. In the beginning when plants are small, you don’t need much nutrient solution to feed and frequency of feeding is also lower but it increases as plants grow

Growing Cucumbers in Hydroponics /Growing Cucumbers Hydroponically Outdoors

After transplantation, I fed them with nutrient solution of strength around EC 1.1 ms/cm or TDS 550 ppm and frequency was thrice a week. Strength of Nutrient solution was increased by EC 0.5 ms/cm or TDS 250 ppm every week until full strength of nutrient solution was achieved which is around EC 2.4 ms/cm or TDS 1200 ppm

You can see below for images at different stages of growth

A week after transplant, female flower buds had also started appearing. It depends a lot on which variety cucumber you are growing. Try to choose a variety that has more number of female flowers

Around March 11, I had also put some wooden stakes to support cucumber vines as the plants were growing well and needed support

Hand Pollinating Cucumbers

If natural pollinators such as Honey bees, etc. are very less in numbers in your garden then you will have to hand pollinate your cucumber plants. Hand pollination requires transferring the pollen from male flower to female flower with the help of cotton wick or a small paint brush or even by rubbing male flower against female flower.

Below you can see that after successful hand pollination, cucumbers started developing very fast

Harvesting Hydroponic Cucumbers

Around March 19, few cucumbers were ready to be harvested. As you can see below, I harvested the first cucumbers and many more later on

As the plants grew, lots of cucumbers were harvested subsequently and the strength of nutrient solution was kept at it’s highest till the termination of the plants

Hydroponic Nutrient Solution for Cucumbers- The Recipe

Growing cucumbers in hydroponics requires a very well balanced hydroponic nutrient solution that can provide all the necessary nutrients to cucumber plants.

You can read my post on DIY Hydroponic Nutrients to know how to make your own nutrient solution for fruiting vegetables at home

If you have read any of my other posts then you know I use a well balanced hydroponic nutrient solution recipe for fruiting vegetables and I have used the same recipe to grow other plants such as Hydroponic Bottle Gourd, Hydroponic Brinjal, or even Hydroponic Broccoli, etc.

Please see below for quantities of different fertilizers required to make hydroponic nutrient solution for cucumbers. These quantities have to be added to 100 Liters of plain R.O. water with EC below 0.3 ms/cm or TDS 150 ppm. Add these hydroponic fertilizers one by one. You can read my article on How make hydroponic nutrient solution for complete details

• Calcium Nitrate 90 grams
• Magnesium Sulphate 53 grams
• Mono Ammonium Phosphate 10 grams
• Mono Potassium Phosphate 13 grams
• Potassium Nitrate 15 grams
• Potassium Sulphate 62 grams
• Iron 12% EDTA 3 grams
• Micronutrients Chelated Mix EDTA 300 mg

If you want in depth information on hydroponic nutrients or how to make stock solution, you can always get in touch with us for our short online training where we teach how to make nutrient solution at home from scratch using commonly available fertilizers and it is going to save huge costs for you as online available nutrients are very costly

You can email me at smgardener99@gmail.com for more details

EC for Hydroponic Cucumbers

When making hydroponic nutrient solution, EC for hydroponic cucumbers should not exceed it’s highest strength which is around EC 2.4 ms/cm or TDS 1200 ppm. Now this value will depend on many factors such as base water EC/TDS or quality of nutrients that you are using. R.O. water that I used has EC of 0.08 or TDS 40 ppm so in my case highest EC value was 2.3-2.4 ms/cm but it can vary

pH for Hydroponic Cucumbers

ph of hydroponic nutrient solution for cucumbers should be kept between 5.5-6.5 where 5.8-6.2 being the sweet spot

If you want you can also watch my Hindi YouTube video on the same topic, you can turn on the English subtitles if you don’t understand Hindi