Hydroponic Basil
Growing basil hydroponically is a highly efficient and compact method that eliminates the need for soil, making it an ideal option for gardeners with limited space. Suitable for both beginners and seasoned gardeners, this guide provides a comprehensive overview of how to grow basil hydroponically,
It covers starting seeds, choosing the right hydroponic system (including Wick, DWC, Ebb and Flow, NFT, Drip, and Aeroponics), and outlines the optimal growing conditions such as pH and EC levels, lighting, and temperature.
Maintenance tips, including reservoir upkeep, algae prevention, pruning, and pest management, ensure your basil remains healthy and productive. Additionally, the guide offers advice on harvesting and storing basil to maximize freshness and flavor.
With an FAQ section to address common queries, this guide is a complete resource for anyone looking to cultivate hydroponic basil indoors or outdoors, providing the necessary insights to enjoy fresh basil year-round.
Table of Contents:
- Starting Seeds
- Hydroponic Systems
- Growing Conditions
- Growing Maintenance
- Harvesting and Storing
- FAQs
Starting Basil
Starting basil seeds for hydroponic systems requires a precise approach to ensure a successful and healthy herb, but isn’t any more difficult than starting seeds in a soil-based garden.
Seed Considerations
When selecting seeds for hydroponic basil, 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.
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 basil plants.
Starting Seeds Indoors
To start basil, plant your seeds in a suitable hydroponic growing medium (such as coco coir pith), about ¼ inch (6.35 mm) deep. This should be done about 6 weeks before the last expected frost if you intend to transfer your basil outdoors (no need to worry about this at all if you’re not transferring). Keep the temperature around 75-85°F (23.9-29.4°C) for optimal germination, which typically occurs in about 10 to 14 days. After sprouting, ensure your new basil plant receives sufficient light for healthy growth using a full-spectrum grow light. Remember to keep the growing medium consistently moist and thin the seedlings as they get bigger.
Starting Seeds Outdoors
Direct sowing basil seeds in your outdoor hydroponic system is best done after the last expected frost has passed, as basil is a heat-loving plant. Ensure your growing medium and the nutrient solution in the reservoir have warmed to at least 50°F (10°C) or higher; then, plant seeds ¼ inch (6.35 mm) deep and 6-12 inches (15.24-30.48 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 4-6 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.
Starting From a Cutting
To start basil from cuttings, cut the stem at a node (the point where leaves join the stem) as roots tend to grow more plentifully from these areas. Strip off the leaves near the base and submerge the trimmed end into a damp growing medium like vermiculite, coco coir pith, or perlite. To boost humidity around the cutting, encase the pot in a plastic covering. Ensure the plastic doesn’t touch the leaves to prevent rot. Position the container in a warm spot out of direct sunlight. You may also want to consider cloning basil aeroponically which should take about 5 days.
Hydroponic Systems for Basil
There are six basic types of hydroponic systems, Wick, DWC, Ebb and Flow, NFT, Drip, and Aeroponics, each offering unique advantages for cultivating plants. Basil, 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 basil, 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, basil 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 basil 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 basil 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 basil through drip irrigation methods, 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 basil, 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. Basil 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 Basil
Basil, 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
Basil prefers a pH range of 5.5 – 6.5 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 and 1.6 to ensure your basil 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 basil seeds about ¼ inch (6.35 mm) deep and 8 to 10 seeds per inch and then slowly thin as they get bigger. If directly sowing outside, space your basil seeds about 6-12 inches (15.24-30.48 cm) apart when planting to accommodate the mature plant size. Proper spacing is vital for adequate air circulation and light penetration, promoting healthy growth and preventing disease.
Germination Time and Germination Temperature
Basil seeds typically germinate around 10 to 14 days when maintained at an optimal temperature between 75-85°F (23.9-29.4°C). Consistent warmth during this stage is key to prompt and uniform sprouting. Basil is unlikely to germinate at all if temperatures are below 50°F (10°C) or above 95°F (35°C).
Time to Maturity
Basil typically reaches full maturity in about 60-70 days after seeding 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 leaves.
Light Requirements
Basil prefers 8 to 10 hours of direct sunlight a day, but needs a minimum of 6 to 8 hours a day. If growing indoors under grow lights, ensure that your basil 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)
Basil grows best in warm-to-hot air temperatures between 80-90°F (26-32°C). Maintaining this range will encourage healthy growth.
Preferred Reservoir Temperature
For basil, 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
Basil does well in a variety of systems, and because of how easy it is to grow, you should find success in any one of them. For beginners, it may be best to try DWC or Wick as these systems are easy to setup and build.
USDA Plant Hardiness Zone
While your local USDA zone is irrelevant if growing inside (under controlled conditions), if growing outside, basil grows best in hardiness zones 10a and 10b. However, you should still try growing basil if you live in 3a, 3b, 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a, 8b, 9a, 9b, 10a, 10b, 11a, 11b, 12a, and 12b. 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 basil throughout the growing process.
Reservoir Maintenance
Regularly check and adjust your nutrient solution’s pH and EC levels to ensure your basil 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
Prune any yellowing or dead leaves to maintain airflow and plant health. Regular pruning before flowering also helps direct the plant’s energy towards producing a large, healthy leaves and forces the plant to grow additional leaves and branches.
Pollination
When growing basil for leaf harvest, pollination is not needed, as leaves are picked before flowering; however, for seed saving or enhancing genetic diversity, allowing flowering and ensuring insect pollination is key.
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.
Plant Support
Basil typically doesn’t need support, but if you find it starting to tip over in your system (especially at the base), it may be a good idea to support the plant using strings, stakes or nets to ensure it remains upright.
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 basil pests include Japanese beetles, slugs and aphids.
Harvesting and Storing Basil
Harvesting and storing basil properly ensures you enjoy the freshest taste and maximum nutrients from your hydroponic garden.
What will your basil look like when it’s ready?
A fully mature basil plant can typically reach 3 feet (91.44 cm) in height and just over 1 foot (121.92 cm) in width, varying with the growing stage, variety, and growing conditions.
When to Harvest
Basil reaches full maturity around 60 to 70 days, but you can start harvesting well ahead of that if you want more flavorful leaves, which are often more aromatic and potent when young. Basil leaves can be anywhere from 1 to 4 inches in length and vary in width from about 1 to 2 inches, depending on the variety. Younger leaves tend to be more tender and have a more concentrated flavor, making them ideal for fresh uses, such as in salads or as garnishes. As basil plants grow, regular harvesting can encourage a bushier growth habit and prevent the plant from flowering, which can alter the flavor of the leaves.
How to Harvest
Harvest basil in the morning after the dew has evaporated but before the heat of the day intensifies, capturing the leaves at their peak freshness. Depending on the amount removed, plants may be harvested every one to seven days, allowing for continuous growth, with basil capable of growing up to 1 inch per day. To encourage the plant to focus on leaf production, snip leaves or stem tips just as the plant begins to bud, but well before any flowers appear (and remove flower spikes as they appear to prevent the plant from setting seed). With careful management, basil can be harvested one to five times throughout the season, promoting a bushier growth and extending the harvesting period.
Storing Basil
After harvesting your basil, store stems in water like a bouquet, and cover loosely with a plastic bag. This keeps leaves vibrant and prevents wilting. Basil can be stored in a cool spot (around 55°F (12.8°C)) for up to two weeks; blanching and freezing is not recommended for basil.
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 basil?
Yes, it is perfectly safe as long as you’re following Food Grade Safe standards.
Does basil grow well in containers?
There are many hydroponic systems that use containers and basil 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 basil roots large?
Basil roots are medium in size/length (comparatively) 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 other vegetable root sizes here.
What kind of nutrients does basil need in a hydroponic system?
Basil needs a nutrient solution with an appropriate balance of nitrogen, potassium, and phosphorus, as well as essential micronutrients such as calcium and magnesium. Utilize a nutrient mix designed for hydroponics, and routinely monitor and adjust the nutrient levels and pH of the solution to ensure optimal basil growth. For more information, try reading our hydroponic nutrients guide.
Can I grow basil hydroponically all year round?
Yes, one of the advantages of hydroponic systems is the ability to control growing conditions, allowing for year-round cultivation. However, you need to maintain optimal light, temperature, and nutrient conditions, which may require additional equipment like grow lights and heaters in colder months.
How do I manage the pH level in my hydroponic system?
Regularly test the pH of your nutrient solution, aiming to keep it in the 5.5 to 6.5 range, which is ideal for basil absorption of nutrients. Use pH up or pH down solutions to adjust levels as needed.
Can I grow basil hydroponically alongside other plants?
Yes, basil can be grown with other plants in a hydroponic system, provided those plants have similar nutrient and environmental needs.
Are there any special considerations for growing basil in a vertical hydroponic system?
In vertical systems, ensure adequate spacing between plants for air circulation and light penetration. Basil does great in vertical systems due to its relatively small size and weight.
How do I know if my basil is receiving adequate nutrients?
To determine if your basil is receiving adequate nutrients, observe the plant’s color and growth patterns; vibrant, green leaves and steady growth typically indicate good nutrient levels. Additionally, regularly check the nutrient solution’s pH and electrical conductivity to ensure it’s within the optimal range for basil.
What other plants can be grown hydroponically?
Technically speaking, anything can be grown hydroponically, but there are certainly some plants/vegetables that make more sense. For more information, check out our hydroponics hobby center, where you’ll find hydroponic vegetable growing guides for commonly grown vegetables/herbs such as green onions, bok choy, cucumbers, spinach, broccoli, etc.
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.