Hydroponic Collard Greens
This comprehensive guide, “Hydroponic Collard Greens: An Easy Indoor and Outdoor Grow Guide,” aims to equip hydroponic growers with the knowledge and expertise needed to navigate the Collard Green growing process. From starting seeds to choosing an appropriate hydroponic system, this guide provides insights into every step, making it a valuable resource for both beginners and experienced gardeners alike.
Table of Contents:
- Starting Seeds
- Hydroponic Systems
- Growing Conditions
- Growing Maintenance
- Harvesting and Storing
- FAQs
Starting Collard Greens
Starting Collar Green seeds for hydroponic systems requires a precise approach to ensure a successful and healthy crop, but isn’t any more difficult than starting seeds in a soil-based garden.
Seed Considerations
When selecting seeds for hydroponic Collar Greens, opt for high-quality, disease-resistant varieties. Ensure the seeds are fresh, as older seeds may have lower germination rates, crucial for a successful hydroponic setup. Remember that the fundamentals behind seeds don’t change; anything that can germinate in soil will generally follow the same pattern in hydroponics as you’re typically just replacing soil with a hydroponics growing medium.
Starting Seeds Indoors
To start Collard Greens, plant your seeds in a suitable hydroponic growing medium (such as coco coir pith), about ½-¾ inch deep. This should be done 5-6 weeks before the last expected frost if you intend to transfer your Collard outdoors. Keep the temperature around 45-85 °F (7.22-29.44 °C) for optimal germination, which typically occurs in about 4-7 days. After sprouting, ensure your new Collard plant receives sufficient light for healthy growth. Remember to keep the growing medium consistently moist.
Starting Seeds Outdoors
Direct sowing Collard Green seeds in your outdoor hydroponic system is best done 5-6 weeks before the last expected frost. Ensure your growing medium and the nutrient solution in the reservoir have warmed to at least 40°F (4.44°C); then, plant seeds ½-¾ inch (1.27-1.91 cm) deep and 8-18 inches (20.32-45.72 cm) apart to accommodate the mature plant size.
Transplanting
If you started your seeds indoors, you can usually transplant them into your hydroponic system within 5-6 weeks. Handle them gently to avoid root damage and ensure the roots make good contact with the nutrient solution in their new system. It’s best to transplant when seedlings are sturdy and have a few true leaves, signaling they’re ready for more vigorous growth.
Growing Mediums
The growing medium you use is entirely dependent on your hydroponic system. It also can come down to personal preference (what’s worked for you, what’s available, etc.). To learn more, read up on hydroponic systems and hydroponic growing mediums to pick the right one. Ultimately, the medium you choose should facilitate nutrient flow and root development while also providing stability to your growing Collard Greens.
Hydroponic Systems for Collard Greens
There are six basic types of hydroponic systems, Wick, DWC, Ebb and Flow, NFT, Drip, and Aeroponics, each offering unique advantages for cultivating plants. Collard Greens, in particular, will thrive in any one of them, making it a versatile choice for hydroponics.
The Wick System
Ideal for beginners, wick systems provide a low-maintenance environment for Collard Greens, using capillary action to deliver water and nutrients directly to the roots. This setup minimizes root disturbance and maintains consistent moisture levels, supporting steady growth without the need for complex equipment or monitoring. Learn more about Wick Systems here.
Deep Water Culture (DWC)
In DWC systems, Collard Green roots are suspended in nutrient-rich water, promoting rapid growth and lush leaves. Using a pump and air stone, this method ensures high oxygen levels at the roots, and is largely considered a hands-off system. However, it does require careful monitoring of water temperature and nutrient concentration. Learn more about Deep Water Culture here.
Ebb and Flow (Flood and Drain)
Ebb and Flow systems periodically flood the root zone with nutrient solution and then drain it away, offering Collard Greens an optimal balance of water, nutrients, and air. This ‘on/off’ cycle encourages strong root development but demands precise timing and control to prevent root rot or drying out. Learn more about Ebb and Flow Systems here.
Nutrient Film Technique (NFT)
NFT systems constantly flow a thin layer of nutrient solution over Collard Green roots, ensuring they receive a continuous supply of water and nutrients while exposed to air. This balance promotes fast, healthy growth, but requires consistent monitoring to avoid blockages in the flow channels. Learn more about NFT Systems here.
Drip System
Drip systems provide a targeted and controlled delivery of nutrient solution to Collard Greens through drip irrigation tubes, allowing for efficient water and nutrient use. This method supports uniform growth and is adaptable to various plant sizes, but requires regular system checks to prevent clogging and ensure even distribution. Learn more about Drip Systems here.
Aeroponics
Aeroponics offers the most advanced and efficient environment for Collard Greens, misting the roots with nutrient solution in a highly oxygenated chamber. This method encourages rapid, robust growth and minimal root disease, but demands precise control of misting intervals and nutrient strength. Learn more about Aeroponic Systems here.
The Kratky Method (Honorable Mention)
The Kratky method is a simple, non-circulating, passive hydroponic technique where plants grow directly in a nutrient-rich solution. Collard Greens can do quite well in this low-maintenance setup, making it an ideal choice for those new to hydroponics or gardeners with limited space. Learn more about the Kratky System here.
Growing Conditions for Hydroponic Collard Greens
Collard Greens, when grown hydroponically, requires specific conditions to thrive. For the best results, it’s essential to carefully manage various factors such as pH levels, seed depth and spacing, germination time and optimal germination temperature, time to maturity, lighting needs, and preferred reservoir temperature.
pH
Collard Greens Prefers a pH range of 6.5 – 7.5 in hydroponic systems. Regularly monitoring and adjusting the pH is crucial, as the correct pH balance ensures nutrient availability and optimal plant health.
EC
Maintain your nutrient solution’s EC between 1.6 and 2.5 to ensure your Greens receive the right concentration of nutrients. Too low of an EC and the plants may show deficiency symptoms, too high and you risk nutrient burn.
Seed Depth and Spacing
Plant your Collard Green seeds about ½-¾ inch (1.27-1.91 cm) deep. If directly sowing outside, space your Collard Green seeds about 8-18 inches (20.32-45.72 cm) apart when planting. Proper spacing is vital for adequate air circulation and light penetration, promoting healthy growth and preventing disease.
Germination Time and Germination Temperature
Collard Green seeds typically germinate around 4-7 days when maintained at an optimal temperature of 45-85 °F (7.22-29.44 °C). Consistent warmth during this stage is key to prompt and uniform sprouting. Collard Greens may have issues germinating if temperatures are below or above 45-85 °F (7.22-29.44 °C).
Time to Maturity
Collard Greens are typically ready to harvest in 65-85 days in outdoor conditions. However, in hydroponic systems under optimal conditions (think indoors, perfect lighting, optimal reservoir temperature, good nutrient levels, etc.), it may be significantly quicker. Keep a close eye as the harvest time approaches to enjoy the freshest, most flavorful Collard Greens.
Light Requirements
Collard Greens prefer 6 to 8 hours of direct sunlight a day, but needs a minimum of 4 to 6 hours a day. If growing indoors under grow lights, ensure that your Greens receive between 12 and 16 hours of light to mimic natural conditions. High-quality, full-spectrum grow lights can ensure your plants receive the necessary light energy for robust growth.
Growing Temperature (Air)
Collard Greens grow best in cooler air temperatures in the Fall and Spring. Cooler air ensures healthy growth and prevents bolting.
Preferred Reservoir Temperature
For Collard Greens, the ideal, “optimal” nutrient solution temperature in hydroponic systems is generally between 68-72°F (20°C to 22.2°C), though some growers may extend this range slightly to 68-75°F (20-24°C). The term “optimal” signifies the most favorable conditions, but slight variations outside this range are typically not a concern. However, note that temperatures above 80°F (27°C) or below 60°F (16°C) will lead to poor growth and potential root diseases.
Recommended Hydroponic System
Collard does well in a variety of systems, but DWC and Ebb and Flow are particularly effective. These systems provide the stable environment and nutrient access that Collards needs to thrive.
USDA Plant Hardiness Zone
While your local USDA zone is irrelevant if growing inside (under controlled conditions), if growing outside, your hardiness zones for Collard Greens include 2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b. Important Note: USDA Zones only apply to USA Growers.
Growing Maintenance
Hydroponic growing can be pretty hands-off, but it doesn’t entirely eliminate the need for maintenance. Much like traditional gardening, you still need to regularly check and maintain your Collard Greens throughout the growing process.
Reservoir Maintenance
Regularly check and adjust your nutrient solution’s pH and EC levels to ensure your Collard Greens receive the ideal balance of nutrients. Change the solution every 2-3 weeks to prevent nutrient imbalances and build-up of harmful substances.
Preventing Algae
Limit light exposure to the nutrient solution and keep your hydroponic system clean to prevent algae growth. Covering reservoirs with light-blocking materials, using opaque (non-transparent) containers, and maintaining a clean environment are effective strategies against algae.
Pruning
Prune any yellowing or dead leaves to maintain airflow and plant health. Regular pruning also helps direct the plant’s energy towards producing a large, healthy leaves.
Pollination
Collard Greens produce edible leaves and pollination is irrelevant for consumption purposes. However, if you’re growing for seed, gentle shaking or brushing of the plant after bolting can help ensure seed production.
Disease Prevention
Keep your hydroponic system clean and monitor plants regularly for signs of disease. Quick identification and isolation of affected plants, along with proper air circulation and nutrient management, are key to preventing the spread of disease. Common Collard Green diseases include Clubroot
Black rot, Black leg, and Alternaria.
Plant Support
As Collard Greens grow, they may become slightly top-heavy. If it becomes an issue (although unlikely), provide support with stakes or nets to ensure the plant leaves remain upright and the stems don’t lean over.
Pest Management
Regularly inspect your plants for signs of pests and maintain a clean growing area to prevent infestations. If pests are detected, use appropriate, hydroponic-safe control methods such as insecticidal soaps or natural predators. Common pests include Cutworm Cabbage loopers, Cabbageworms, Flea beetles, Cabbage root maggots, Cabbage aphids, Slugs and snails, Nematodes.
Harvesting and Storing Collard Greens
Harvesting and storing Collard Greens properly ensures you enjoy the freshest taste and maximum nutrients from your hydroponic garden.
What will your Collard Greens look like when they’re ready?
A fully mature Collard Green plant can be over a foot in height and roughly a foot and a half in width. Additionally, as they are somewhat of a big plant, make sure to account for their large leaves, which can be greater than 6 inches in length and around 3-6 inches in width.
When to Harvest
Leaves can be harvested whenever you feel is best (comes down to personal preference), but they’re generally cut when they’re over 6 inches in length.
How to Harvest
To harvest, simply cut the leaf off at it’s base. You can start with the lower leaves and move your way up to newer growth.
Storing Collard Greens
After harvesting your Collard Greens, store in a perforated plastic bag without washing to prevent mold and preserve freshness. Collard Greens can be stored in the refrigerator (between 32-40°F (0-4.4°C)) for up to two weeks; for longer storage, consider blanching and freezing it to maintain quality and nutritional value (should last you around 8-12 months).
FAQs
Can I just top off my nutrient solution in my hydroponic system?
It’s recommended that you change the nutrient solution in your reservoir out every 2-3 weeks. However, for everyday hobbyists, this really depends on personal preference how serious you want to take the hobby. If you’re growing for someone else, it may be best to “go by the book” and fully change it out. If you’re growing for yourself, the choice is really yours. Many hobbyists do just fine by topping off the water/nutrients when it gets low and then cleaning out the system after a few grows.
Is it ok to use plastic to grow Collard Greens?
Yes, it is perfectly safe as long as you’re following Food Grade Safe standards.
Are Collard Greens Healthy?
Collard Greens are very healthy vegetables. Out of our healthiest ranking list, Collard Greens rank #10.
Do Collard Greens grow well in containers?
There are many hydroponic systems that use containers and Collard Greens will do well in any one of them. For more information, read up on our container size standards for vegetables guide.
Are Nutrient Deficiencies Common?
Hydroponics is truly a trial and error hobby and if you’re just starting out, you’re probably going to have some nutrient issues. Make sure to continually monitor your plants and look for any abnormalities. If anything looks off, do some ‘plant deficiency research’ and adjust as needed.
Are Collard Greens roots large?
Collard Green roots are small to medium in size/length and will do well in most hydroponic systems (aka size shouldn’t be a problem). If you’d like to learn more, you can read up on vegetable root sizes here.
Where can I find more information on hydroponics?
If you’d like to learn more about hydroponics, give our Hydroponics Hobby Center a read. The Hydroponics Hobby Center contains system guides, plant guides, charts, etc. that will help you get started. You can also download our free guide below or enroll in our online course, Hydroponics 101. You can also read and explore our big list of hydroponic designs on Amazon with 51 Hydroponic Designs: DIY Designs for Beginner Hobbyists.
