Most of us treat fertilizing as a guesstimate. Out come the balanced kind from shed, and we sprinkle it over the area and hope for the best. Often, you get lush foliage but veggies is tiny.
Think of each plant in your garden as a person with individual dietary requirements. Would you feed a powerlifter the same thing you serve a marathon runner? It is no different then giving sweet corn the same amount of nitrogen you give lettuce.
How to Feed Your Garden Plants
Knowing which plants are light and heavy feeders are one of the greatest changes you can make to your gardening tactics. You can see those requirements broken out nicely in this visual guide.
Those are what we call heavy feeders. Sweet corn is at the very top of the list because it pulls heavily from the nitrogen supply. It requires a big preplant dose, and then another when the stalks hit knee-high. Skimp on nitrogen for your corn, and you’ll get pale, stunted ears.
At the other end of the scale, legumes such as bush beans is self-sufficient; they has a special relationship with certain bacteria that lets them take their own nitrogen from the air. Applying heavy doses of nitrogen to beans isn’t good practice, it will encourage weak, leafy growth at the expense of pod production, which seems counterintuitive but is true. Match the fertilizer to the plant’s biology, not just the color of its leaves.
The timing on application can be almost more important than which nutrient you’re applying. First-timers often make the rookie error of applying all at once at planting time. This is fine if your crop is a light feeder (lettuce, radish) with a relatively brief life cycle that doesn’t require much. But with heavy feeders such as squash or tomatoes, you want to time things carefully.
These plants has long seasons and go through periodic surges of hunger. You should of put half the dose in at planting time, when a root system is beginning to take hold. Then, add the other half when the plant begins to set fruit. With tomatoes in particular, this is the moment their need for nutrition realy skyrockets. With the splits, the plant gets what it needs when it needs it and you avoid wasting fertilizer by having it sit unused in the ground or wash away.
People often forget what the other two do differently. Nitrogen is what most of us think about; it drives leafy green growth. In fact, phosphorus (one part of the N-P-K ratio) helps flowers and roots, too, but especially roots. If your beet or carrot roots has turned out woody and forked instead, they may not have had sufficient phosphorus. They could be well-rooted tops with nothing to show below except a mess.
Finally, potash (or potassium) strengthens cell walls and boosts disease resistance, which is critical to getting good-quality fruit later in the season. Giving those tomatoes an extra boost of potassium just before setting fruit can mean the difference between a rotting-on-the-vine tomato and one that stands up to harvest time.
The same goes for organic amendments, though at a slower rate of action. Compost is slow release, feeding the soil microbiome over time. You can get a targeted boost from meals like bone meal or blood meal. But again: Patience is required with the organics. You cannot water them in as a quick fix the way you can with those granular synthetics. The aim instead is to establish a strong structure in the soil, one that holds nutrients well.
To do this, first have your soil tested. This is the smartest thing you can do, since it will tell you what’s present and allow you to avoid over-applying something that’s already plentiful. Then match your rate of amendment to the stage of growth of your plants based off guesswork. Your garden will look like a system instead of a battle once you stop guessing and start taking action. And then the real abundance starts.