Here is a primer on Fertilizer. Not really complicated, but it can seem that way when you are faced with a wall of choices at your local nursery. Take a deep breath and let’s get through this!
A Guide to Fertilizing
Plant fertilizer comes in liquid and powdered forms. Liquid fertilizer can be sprayed on leaves or poured onto the roots while powdered fertilizer needs to be worked into the soil or scattered on top. Yet another fertilizing choice is the fertilizer stake, which is inserted in the soil. Some fertilizers are formulated for particular plants, such as roses or lawn grass.
Most fertilizers contain three nutrients; numbers on their packages give the proportions of these nutrients. The first number is nitrogen, the second is phosphorous, and the third is potassium. A 15-30-15 fertilizer contains 15 percent nitrogen, 30 percent phosphorous and 15 percent potassium.
Chemical elements — primary, secondary and trace — play a vital role in growing healthy plants. Look at the fertilizer pack, where you’ll find the symbols N:P:K, which are the ratios of the three major elements — nitrogen, phosphorous and potassium.
• Nitrogen (N) — important for vegetative growth (leaves, stems and fruit), making leaves lush. Herbs grown for their foliage, such as mints, need a higher nitrogen value (for example, 12:1:5).
• Phosphorous (P) — for cell formation and chemical reactions involved in growth and reproduction. It promotes root development as well as seed, flower and fruit production.
• Potassium (K) — important for fruit-bearing trees and vegetable and flower crops, as it improves the quality of flowers and fruits. It aids plant health, stem and cell thickness and the movement of water within plants, providing resistance to pests, diseases, drought and heat. For a good flush of blooms, flowering plants need a fertilizer containing more potassium (6:14:17).
• Calcium (Ca) — needed for healthy cell walls and root growth.
• Magnesium (Mg) — a key component in the green coloring of plants (that is, chlorophyll) and therefore vital for photosynthesis, a process whereby plants use the energy of sunlight to produce sugars.
• Sulphur (S) — part of the flavor and odor components (for example, onions and cabbages).
• These are iron (Fe), manganese (Mn), boron (B), copper (Cu), zinc (Zn) and molybdenum (Mo), which are only needed in minute quantities.
I’ve been fertilizing everything this month. The weather’s warming up and plants are springing to life. They could use a good meal. I use Fish Fertilizer. The brand I’m using is 5-1-1. I can feed more often, and this fertilizer doesn’t burn plants since it’s a natural product.
An all-purpose fertilizer will probably serve your gardening needs. Use it according to the manufacturer’s instructions. When in doubt, use too little rather than too much, since too much fertilizer can burn plant roots or contribute to unwanted plant growth. Fertilizer is seldom needed for trees or shrubs (except roses). Use sparingly with perennials. Most annual flowers and vegetables benefit from regular, light fertilization. Plants in containers need more feeding because nutrients wash out during watering.
Okay, fertilizing doesn’t have to be complicated. Yes, there are reasons why certain plants should be fed certain times of the year, but don’t let that overwhelm you. Gardening is a process and the learning never stops. Here’s my rule of thumb for fertilizing. Lighter regular feedings rather than heavy, and less often. As you get more comfortable with the process, you can move up to the next level and be more specific to the plants you are fertilizing.
Don’t fertilizer when plants are resting, typically in the winter. You don’t to encourage delicate growth at a time when the weather is colder and harsh.
For plants that are heavy bloomers, I typically fertilize when I first see buds, then another dose as the last third of the flowers are blooming. My theory is that they have worked hard and they need a nourishment. I had gardenias that I struggled with for a number of years until I figured this out. They would bloom prolifically, but when it finished they were sapped and the bugs moved in. Everyone needs a snack when they’re tired. Okay, get out there and do your magic. Your plants will thank you!