Hydroponics offers an alternative to traditional soil gardening, allowing for the cultivation of flavorful garlic in a controlled, soilless environment. This method provides the advantage of year-round growth, independent of seasonal weather conditions, and enables faster yields, particularly for garlic greens and scapes. By managing nutrient delivery and environmental factors, growers can optimize conditions for either rapid leaf production or the slower process of bulb formation.
Preparing the System and Seed Stock
The initial setup requires selecting a suitable hydroponic method, such as Deep Water Culture (DWC) or Nutrient Film Technique (NFT). DWC suspends the roots directly in a nutrient solution and is often preferred for its ease of maintenance. NFT provides a thin film of solution to the roots, which can be beneficial for oxygenation.
Garlic begins as a single clove, which should be sourced from healthy, organic, and disease-free bulbs. Separate the bulb into individual cloves just before planting, selecting the largest and firmest ones for the best results. For growers focused on producing mature bulbs, the cloves must undergo a cold treatment called vernalization. This involves storing the cloves at 38 to 40 degrees Fahrenheit for 6 to 8 weeks to mimic winter, triggering the hormonal changes necessary for bulbing.
Once prepared, the clove is set into an inert growing medium such as rockwool or clay pebbles (hydroton) within a net pot. Position the clove with its flat, root-end facing down and the pointed tip facing up, leaving the top slightly exposed. The net pot is then placed into the system so that the base of the medium or developing roots are in contact with the nutrient solution. This initial contact encourages the development of the root system, which is crucial for nutrient absorption.
Maintaining Optimal Growth Conditions
Managing the nutrient solution must adapt to the plant’s growth stage and the desired harvest goal. For the initial vegetative growth phase, which produces the greens and scapes, a nutrient solution with a higher proportion of Nitrogen (N) is necessary to support robust leaf and stem development. This high-Nitrogen formula promotes the lush, green growth sought after when harvesting garlic greens.
When the goal shifts to forming large bulbs, the nutrient profile must be transitioned to a formula with lower Nitrogen and higher levels of Phosphorus (P) and Potassium (K). Phosphorus is essential for energy transfer and root development, while Potassium assists in bulbing and overall plant strength. Throughout the growth cycle, the solution’s pH should be maintained in a slightly acidic range, between 6.0 and 6.5, to ensure the optimal uptake of all macro and micronutrients.
Monitoring the Electrical Conductivity (EC) or Parts Per Million (PPM) of the solution, which measures nutrient concentration, is important, with a target range of 1.2 to 2.5 mS/cm generally recommended for garlic. Environmental controls are just as important as nutrient management, starting with light, where garlic requires 12 to 16 hours of light per day for healthy growth. The ambient temperature should be kept cool, between 60°F and 65°F, and good air circulation is necessary to prevent the development of mold or mildew.
Harvesting and Post-Harvest Curing
Harvesting the greens and scapes allows for continuous yields without terminating the plant’s life cycle. Garlic greens, which are the edible shoots, can be trimmed once they reach a height of four to seven inches, by snipping the top third of the shoot with clean scissors. This method allows the clove to continue producing new shoots. Scapes, the curly flower stalks produced by hardneck varieties, should be removed when they first curl to redirect the plant’s energy toward bulb formation.
For bulb harvesting, the timing is indicated by visible cues from the foliage, typically when the lower three to five leaves have turned yellow and begun to flop over, while the upper leaves still retain some green. This signals that the plant has finished transferring its energy and nutrients into the bulb. The bulb is carefully removed from the net pot and growing medium, being sure to avoid damage to the outer wrappers.
Once harvested, garlic bulbs require curing to dry the outer papery wrappers and seal the neck, preparing them for long-term storage. The bulbs, with stems and roots still attached, should be placed in a warm, dry area with good airflow, such as a shaded shelf or a covered porch. Curing is typically complete after two to four weeks, when the neck is dry and the outer wrappers are crisp. After curing, the roots and stems can be trimmed, and the finished bulbs are best stored in a cool, dark place with moderate humidity.