How do I improve the flavor of leafy greens?
I’m a container farmer in Sacramento and I’m wanting to increase levels of flavor. I’ve read about many factors that contribute including stress, sulfur, calcium — micro nutrients... However, I have an NFT system that houses many plants at different stages...I grow leafy greens, herbs, micros...so the plants bring in a different stage of life. What tricks can I use? I’ve been told my greens are beautiful but sometimes have a light flavor especially on greens that have that punch such as cress, mustard, etc. What do you think?
You already touched on the importance of your fertilizer program, so first and foremost, be sure you have that dialed in. Choose fertilizers and supplements that contain a full range of micronutrients, then add humic and fulvic acids to help your plants uptake these nutrients better. This is especially important for increasing iron levels. Chlorophyll manufactures sugars during photosynthesis, and iron acts as the catalyst. If iron is readily available, plants will efficiently produce sugar.
Seaweed is excellent for increasing root mass and chelating micronutrients to make them more available. The increased root mass offers more surface area for minerals to be taken up into the plant.
Also, be sure your nitrogen levels aren’t too high because excessive nitrates can inhibit your crop’s ability to uptake nutrients. Excessive nitrogen reduces the sugars, acids, and antioxidants in plants, which are the compounds that create flavor. In fact, many gardeners who grow their own greens will intentionally increase their nitrogen levels to reduce the bitter taste some greens can have.
Monitor your nutrient solution’s pH and electrical conductivity (EC) daily. For greens, keep your pH around 5.8-5.9. Different varieties require different EC’s for best flavor. For example, lettuce generally does well around 1.4 mS/cm, whereas spinach thrives at 1.8 mS/cm.
As you’ve mentioned, stressing your plants will produce defense chemicals that improve flavor. Jasmine actually produces a chemical that will warn its neighbors when an attack is underway so they can prepare themselves. You can create this effect in your garden by spraying jasmine floral water, which contains the chemical methyl jasmonate, on your plants so they produce their own defense chemicals.
You can also mimic moisture stress in your NFT system by increasing your EC slightly to create a higher osmotic potential in the root zone. This is a proven way to increase flavor in your crops.
The weather and time of day can also affect flavor. Sunlight directly affects sugar content. Sugars will be higher on sunny days and lower on cloudy days. Moisture content is higher in the morning, which dilutes sugars, so harvest in the morning to reduce flavor, and later in the day to increase flavor.