When you don’t know what the three big numbers on the side of a bag of fertilizer mean, that’s confusing. You’re looking at all those colorful sacks in garden aisle, wondering which one will turn your grass thick or your tomatoes fat. It isn’t magic, actualy, but it is chemistry.
The big N stand for nitrogen, to promote leaf growth. The P stands for phosphorus, to promote bloom and root development. And the K stand for potassium, to promote general plant health. After seeing this pattern, you get it. No more random bags, no more; just what the plant require.
How to Use Fertilizer
Each crop requires nutrients in a slightly different way from the soil. For example, corn must has plenty of nitrogen to develop tall stalks. However, adding extra isn’t necessary because beans produces their own nitrogen from air. Too much nitrogen will be harmfuler to beans. What does this mean? It means you don’t want to treat each plant equally. Some plants might get too many nutrient while others might not gets enough. Use the guide to see which plants needs the most (like corn) and less (like beans). Before deciding on a bag, examine the plant first.
Another thing about feeding your plants, in addition to what ratio to use, is knowing when the right time is. Like with people, when they’re babies, you don’t feed them the same size portion as you would someone who’s grown up. Ditto with plants; seedlings respond best to a gentle beginning, such as half-strength diluted fertilizer. Their young roots aren’t tough yet and can absorbs by heavy doses of strong synthetics. As the plant matures, you add more. When tomato begins to set fruit, for instance, that’s when it’s in need of more nutrients. It is too late to begin feeding the plant then. What you fed it when it was smaller is what the plant has determined it could of carry through into fruit production. It is a small step, but it makes big difference.
Another consideration is how it’s delivered. Because its nutrients are pre-dissolved, liquid fertilizer take effect rapidly. This is good if you have limited soil, such as in a container garden. You mix it in with watering every couple of weeks, keeping the levels steady.
Granular fertilizer goes into ground and feeds gradually when broken down by moisture. This is good if your goal is sustained feed, such as in an established lawn or bed. In a smallish pot, the danger is that salts will accumulate to toxic levels; not a good use for granules. A big lawn is not a good customer for liquid fertilizer; too much money and a lot of labor to apply. Match the format to root zone.
Feeding plants varies by season. Feed them an extra push in springtime; that’s when they begin pushing new growth. In late summer, back off on feeding. Fall high-nitrogen feeds promote soft growth… No good comes with frost. Promote root protection against winter with phosphorus and potassium instead. It’s easy to see how the routine diminishes on a seasonal chart. Growth includes rest. The garden (and the gardener) can get exhausted if we try to push it hard all year long.
That’s the thing with fertilizer: Once you understand those few things, it becomes your friend. Read the label. Look for the NPK number, and think about how much that plant eats. When is the time of year to feed? How much do you put down where? And then…patience; sun; water. Let the other stuff happen.
Stop reading the numbers, and let the plants teach you what they want. Observe the plants.