Water-soluble fertilizer, such as Miracle-Gro, Rapid-Gro, Dyna-Gro and other generic formulas, is a fertilizer designed to mix with water and apply to the foliage of flowers and vegetables. This foliar fertilizer penetrates the leaves and goes to work immediately, providing essential nutrients to plants. Excess solution drains into the soil where roots absorb and carry the nutrients to the plant. For many gardeners, using foliar feeder spray in the garden brings about the rapid results they desire, while eliminating the need to fuss with side dressing and mixing granular fertilizer into the soil.
Choosing a formula
Each manufacturer produces it own formula, but the proportions are basically the same. All-purpose formulas typically contain a higher amount of nitrogen and with slightly less phosphorus and potassium. All-purpose formulas can be used successfully on all garden vegetables and flowers. Some formulas designed for tomatoes contain less nitrogen and more phosphorus and potassium, better suiting the needs of tomatoes. I have used both successfully with my tomatoes. However, I do recommend using plant food for tomatoes to produce the best tomatoes and using the all-purpose formula for other garden vegetables.
Fertilizer is typically labeled with three numbers indicating the balance of nutrients in the formula. The first number represents the percentage of Nitrogen, the second represents Phosphorus and the third represents Potassium. All three nutrients are vital to the health of your plants.
Nitrogen is a major nutrient responsible for plant growth. Although necessary for rich, green foliage and healthy plant growth, an overabundance of nitrogen produces heavy (often deep green) foliage with few blooms or fruit. This often poses a problem in growing tomatoes. A lack of nitrogen, on the other hand, causes stunted growth with reduced leaf size, yellowed foliage and leaf drop.
Phosphorus is necessary for good root formation, but also plays a vital role in producing flowers, fruit and seeds. A phosphorus deficiency typically produces plants with weak support systems, dull or small blooms and may reduce overall yield of vegetables.
Potassium's major role in plant growth is in regulating water. Potassium maintains turgor (rigidity in the plant from water pressure), prepares plants for the stress of drought and increases resistance to disease. Phosphorus also improves winter hardiness. Without adequate amounts of phosphorus, plants cannot uptake the water and nutrients they need to thrive.
Water-soluble fertilizer is specially formulated to mix easily with water. It can be used in a feeder attached to the hose to water the entire garden or mixed in a bucket or watering can and applied to specific plants. Because it is a foliar feeder, the solution can be applied directly to the plant's leaves, where absorption begins. Excess solution drains into the soil where it is taken up by the roots.
I've been using water-soluble foliar fertilizer on my garden for over 20 years and have always been happy with the product. Not only does it supply the nutrients my plants need, it is easy to use and convenient to store. I often see a noticeable difference in my plants within a day or two as the foliage tends to "green up" quickly and exhibit a spurt of new growth.