Marvel of Four Seasons is a pre-1885 French heirloom variety. It is a butter-head type of lettuce variety with long, slender leaves. It supposedly resists getting bitter during warm summers. Let’s be honest, lettuce doesn’t have tons of flavor to begin with, but to me the flavor of this one is actually quite pleasant.
Here I will be testing 2 different types of fertilizer blends:
- Masterblend 4-18-38 + calcium nitrate + magnesium sulfate. This is my normal blend, and it works well. Since it is supplied as a dry powder it is very inexpensive.
- Dyna-Gro Liquid Grow 7-9-5. This is a liquid concentrate which I normally only use for starting my seedlings. It is more expensive than the dry fertilizers, but is much more convenient to work with, especially when making up small batches of hydroponic solution (< 2 gallons).
Dec 24, 2015 = Day 0. Started from seed (Botanical Interests). Moistened with dilute fertilizer solution: 1 mL (1/5 tsp) Dyna-Gro Liquid Grow per gallon of tap water. Nutrient concentrations (in ppm): N 18, P 24, K 13, Ca 5, Mg 1, S 0.13, Fe 0.26, Mn 0.13, B 0.05, Zn 0.13, Cu 0.13, Mo 0.002, Ni 0.0003, Co 0.004. pH = 7.0.
Dec 27, 2015 = Day 3. Seeds germinated. Transferred to grow room, receiving 3 hours sunlight + 5 hours LED grow-light per day.
Jan 4, 2016 = Day 11. To give plants more light, placed plants directly under a fluorescent light (2-ft. T8 bulb, 17W, 6500k) for 14-16 hours per day.
Jan 8, 2016 = Day 15. Installed plants in 1.2 gallon containers:
Solution #1 composed of: 1.2 gal tap water, 2.4 g MasterBlend 4-18-38, 2.4 g calcium nitrate, 1.2 g magnesium sulfate, 0.25 mL Dyna-Gro Pro-TeKt, 1.2 mL pH Down. pH = 6.0.
Solution #2 composed of: 1.2 gal tap water, 7.2 mL Dyna-Gro Liquid Grow, 0.25 mL Dyna-Gro Pro-TeKt. pH = 6.0. No pH adjustment needed.
Nutrient concentrations (in ppm):
Jan 16, 2016 = Day 23. Thinned down to 2 plants per container. Transferred plants to indoor grow room with LED lights. At this point, the plants in Liquid Grow seem to be doing slightly better than the plants in Masterblend. Interestingly, there is almost no root development on the Liquid Grow plants, while the roots are about 4-inches long on the Masterblend plants.
Feb 18 = Day 56. Starting to harvest leaves from these plants. At this point, the plant grown in Masterblend has used more of its fluid than the plant grown in Liquid Grow.
Feb 24 = Day 62. Harvested all leaves from both plants. Final statistics:
Masterblend plant: Used 1.1 gallons of fluid. Final pH of fluid = 8.0.
Liquid Grow plant: Used 0.8 gallons of fluid. Final pH of fluid < 4.0.
Compared the root systems:
Although the upper portions of both plants were not too different, it is clear that the root system of the plant grown in Masterblend looks much better than the plant grown in Liquid Grow. In both cases, the pH started out at 6.0, but neither system maintained a stable pH throughout the growing period. It seems that the Masterblend’s spike up to 8.0 was tolerated better than the Liquid Grow’s drop down to below 4.0.