When plants reach three weeks of age, are about 4-inches in height, or after thinning, weekly fertilizing should begin to replenish the nutrients in the soil being used up by seedlings and plants to develop. As with all concentrated fertilizers, ensure that you are mixing only the quantity to be used at the ratio recommended on the packaging.
If you have a foliage-only garden such as the Salad, Herb, or Taco Seedsheet kits, there are two options for fertilizers which we have tested and recommend. The first is Fox Farm Grow Big, which while not organic, is the market standard and contains tons of beneficial, natural and synthetic ingredients, keeping costs low and yields high. This concentrate has an elevated level of nitrogen which facilitates foliage growth, making it the perfect fertilizer for use throughout the lifetime of greens and herb plant varieties.
The second fertilizer option for foliar plants is Neptune’s Harvest Organic Fish-Seaweed Fertilizer, which works wonders for strong greenery with increased yields, but some may be put off by the pungent fish odor. This fertilizer can also be used throughout the life stages of fruiting plants like tomatoes, peppers, or cucumbers. It will boost the natural blossom production of these plants and increase the natural sugars in the fruits, creating more flavorful produce.
If you have fruiting varieties of plants such as tomatoes, peppers, or cucumbers, and do not wish to use Neptune’s Harvest, we recommend a three-stage Fox Farm fertilizer approach, which can be purchased as a trio.
First use Fox Farm Grow Big, as foliage first needs to be built before transitioning life stages.
As soon as plants begin to develop blossoms a different fertilizer should be applied and Grow Big fertilizer should be ceased entirely. Diluted Tiger Bloom fertilizer should instead be applied weekly. The Tiger Bloom concentrate is formulated with elevated levels of phosphorus, which is a key nutrient for blossom development. The more blossoms which develop on plants will lead to more fruit development.
Finally, once blossoms begin to transition to fruit development, we recommend terminating the application of Tiger Bloom and switching to the third stage, weekly diluted Big Bloom fertilizer, which has elevated levels of potassium. Potassium is a key component in many of the processes which assist in the development and maturation of fruit.