Proper general fertilization isn’t really something you can describe in one setting. Fertilizing the right way depends on what you’re growing and the results you’re looking for. But there is one constant- you should do your best to do it right. Different plants have different needs. Your lawn is going to have far different needs than your vegetable beds, for example. In this article, I’m going to focus on the basic fertilization techniques appropriate for the most general of situations, meaning for basic landscaping and basic growing conditions of commonly used landscape plants. More detailed help will come later. Sometimes it’s better to start with a good, general idea.
For most trees and shrubs, the spring brings drastic physiological changes as the plant begins to reawaken from their winter slumber. Hormones in the plant induce the formation of new leaves, and the buds of those new leaves break open. Gibberellins (a plant hormone) push the now growing stems toward the light, requiring energy to do so. You’ll maximize your plant’s potential to not only photosynthesize its own food, but grow to it’s full potential that year by providing the right amount of nutrients that it will need. That said, there are many plants that don’t need much in the way of extra fertilization, and excess fertilization can create unwanted growth- such as explosive foliage leading to smaller blooms. But for simplicity, here’s a general fertilization schedule for most landscape plants.
• Offer acidifying fertilizers for rhododendrons, conifers, camellias, and hydrangeas (if the color of the blooms matter to you). Be sure to follow the manufacturer’s directions carefully. For a more natural alternative, you can collect pine needles or other conifer needles and lay down about a two inch layer around the base of each acid loving plant. A general fertilizer works well for annuals, perennials, flowering and fruiting trees, and shrubs that don’t have specific pH requirements. Trees like cherry, apple, crabapple, shade deciduous trees, most common examples of trees. Commonly found annuals like impatiens, petunias, and others fall into this category. Once again, follow the manufacturer’s directions. For a natural alternative, save grass clippings, mulched fall leaves, manure, and compost are all good fertilizers. Veggies need a good amount of general fertilizer too. They typically do better if you allow them time to establish their roots first in the spring before you begin a fertilizer regimen, right after transplant.
• For newly planted shrubs, trees, and perennials, it’s a good idea to give the plant a few weeks before you begin fertilizing them. You can also use a special fertilizer made especially for new transplants that encourage root development right off the bat. Follow the directions on the package carefully.
• For your lawn, apply a nitrogen rich fertilizer on a cloudy, somewhat moist day in the spring. Fertilizers can burn your grass if you apply it on a hot, dry day.
There are some special ways to fertilize if you’re hoping for specific results. Generally speaking, nitrogen encourages top, leafy growth in all plants. Phosphorus encourages flowering and fruit development. Potassium encourages strength and vigor. General fertilizers usually are made with a balance of these three nutrients, and are appropriate to use all year long during the growing season. For grasses who don’t really flower or have a need to put on girth and strength, they use a lot of nitrogen as they grow quickly. If you’re hoping to create more blooms on your roses, choose a fertilizer that’s higher in phosphorus and lower in nitrogen.
This is an extremely general description of how to use fertilizers in your garden. Depending on the plants that you have, the soil composition you have, and the results you’re looking for, your needs may differ. The best rule of thumb is to apply your fertilizer via manufacturer’s instructions.