Hydroponic Cabbage
This comprehensive guide, “Hydroponic Cabbage: An Easy Outdoor and Indoor Grow Guide,” aims to equip hydroponic growers with the knowledge and expertise needed to navigate the cabbage 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 Cabbage
Starting cabbage 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 cabbage, 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 cabbage, plant your seeds in a suitable hydroponic growing medium (such as coco coir pith), about ¼-½ inch (6.35-12.7 mm) deep. This should be done 5-6 weeks before the last expected frost if you intend to transfer your cabbage outdoors (frost date is irrelevant if you plan to keep growing indoors). Keep the temperature around 60-85°F (15.6-29.4°C) for optimal germination, which typically occurs in about 3 to 5 days. After sprouting, ensure your new cabbage plant receives sufficient light for healthy growth. Remember to keep the growing medium consistently moist.
Starting Seeds Outdoors
Direct sowing cabbage seeds in your outdoor hydroponic system is best done 5 to 6 weeks before the last expected frost. Ensure your growing medium and the nutrient solution in the reservoir have warmed to at least 50°F (10°C); then, plant seeds ¼-½ inch (6.35-12.7 mm) deep and 12-24 inches (30.5-61 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 to 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 cabbage plants.
Hydroponic Systems for Cabbage
There are six basic types of hydroponic systems, Wick, DWC, Ebb and Flow, NFT, Drip, and Aeroponics, each offering unique advantages for cultivating plants. Cabbage, being a relatively large and leafy vegetable, can thrive in any one of them, but certain setups may be better suited to its growth requirements and characteristics.
The Wick System
Ideal for beginners, wick systems provide a low-maintenance environment for hydroponic vegetables, 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. For cabbage, however, it’s important to note that wick systems may not provide enough water and nutrients as the plant matures, necessitating careful monitoring and adjustments. Learn more about Wick Systems here.
Deep Water Culture (DWC)
In DWC systems, cabbage 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 cabbage 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 cabbage 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. This is especially important when growing cabbage, as cabbage roots are fairly large and can easily cause a backup. Additionally, some NFT systems may not be enough support to hold heavy cabbage plants. Learn more about NFT Systems here.
Drip System
Drip systems provide a targeted and controlled delivery of nutrient solution to cabbage 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 cabbage, 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. Cabbage can do quite well in this setup, but because cabbage has such high nutrient/water demands, it may not be the best plant/system combination for beginners. Learn more about the Kratky System here.
Growing Conditions for Hydroponic Cabbage
Cabbage, 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
Cabbage prefers a pH range of 6.5 – 7.0 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 2.5 – 3.0 to ensure your cabbage receives 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 cabbage seeds about ¼-½ inch (6.35-12.7 mm) deep. If directly sowing outside, space your cabbage seeds about 12-24 inches (30.5 to 61 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
Cabbage seeds typically germinate around 3 to 5 days when maintained at an optimal temperature of 60-85°F (15.6-29.4°C). Consistent warmth during this stage is key to prompt and uniform sprouting.
Time to Maturity
Cabbage is typically ready to harvest in 65-95 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 cabbage.
Light Requirements
When growing outdoors, cabbage prefers 8 to 10 hours of direct sunlight a day, but needs a minimum of 6 hours a day. If growing indoors under grow lights, ensure that your cabbage receives 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)
Cabbage grows best in cooler air temperatures between around 60°F (15.6°C). Temperatures higher than 75 will typically induce bolting.
Preferred Reservoir Temperature
For cabbage, 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
Because cabbage is such a large plant (and quite heavy), the two systems that work best are Ebb and Flow and Deep Water Culture. Both of these systems should provide enough support to keep the plant upright and healthy.
USDA Plant Hardiness Zone
While your local USDA zone is irrelevant if growing inside (under controlled conditions), if growing outside, your hardiness zones for cabbage include 1a, 1b, 2a, 2b, 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, and 9b (but still worth trying in 10a, 10b). 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 cabbage throughout the growing process.
Reservoir Maintenance
Regularly check and adjust your nutrient solution’s pH and EC levels to ensure your cabbage receives 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
Pruning cabbage involves removing outer leaves that are old, damaged, or yellowing to encourage better growth and airflow around the plant. This selective removal helps to concentrate the plant’s energy on developing a dense, healthy head, resulting in a higher quality harvest.
Pollination
Cabbage, being a self-pollinating plant, doesn’t require pollination to produce its edible leaves. 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. Cabbage diseases include blackleg, yellows, leaf spot, and black rot.
Plant Support
Supporting cabbage plants as they grow is crucial, especially for varieties that produce large, heavy heads. Depending on your system, using stakes or cages can help maintain stability and prevent the plants from toppling over under their own weight, ensuring the cabbages develop properly and remain healthy throughout their growth cycle.
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 for cabbage include cabbage worms, slugs, caterpillars, cutworms, cabbage loopers, nematodes, root maggots, and cabbage aphids.
Harvesting and Storing Cabbage
Harvesting and storing cabbage properly ensures you enjoy the freshest taste and maximum nutrients from your hydroponic garden.
What will your cabbage look like when it’s ready?
A fully mature cabbage plant typically reaches 1 to 2 feet (10.5 to 61 cm) in height and 1 to 2 feet (10.5 to 61 cm) in width, varying with the variety and growing conditions.
When to Harvest
Harvest cabbage when its heads have grown to their full size and feel firm and compact. If growing from seed, this should be take about 65-95 days.
How to Harvest
Trim the stem beneath the head, ensuring to leave 2-3 outer leaves intact for protective coverage. Once cut, move it out of the sun as quickly as possible to prevent ‘sublister’.
Storing Cabbage
After harvesting your cabbage, store in a perforated plastic bag without washing to prevent mold and preserve freshness. Cabbage can be stored in the refrigerator (between 32-40°F (0-4.4°C)) for up to five months; for longer storage, consider blanching and freezing it to maintain quality and nutritional value (should last you around 8-12 months).
FAQs
How many types of cabbage are there?
There are three varieties of cabbage. The common cabbage features dark green leaves, while the Dutch cabbage, known for its larger heart and leaves along with a milder taste, displays pale green to white leaves. Lastly, the red cabbage is distinguished by its purplish-hued leaves.
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 Cabbage?
Yes, it is perfectly safe as long as you’re following Food Grade Safe standards.
Does cabbage grow well in containers?
There are many hydroponic systems that use containers and cabbage 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 cabbage roots large?
Cabbage roots are medium in size/length and will do well in hydroponic systems that are a little more roomy (such as Ebb and Flow, Drip, or DWC). 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.