By Pat Dray
The Garden Spot
Pat Dray.
Most of us understand that we need to feed our gardens and house plants but are often confused by all the choices in the plant food world.
The labels will typically show three numbers that represent the proportion by weight of N (nitrogen), P (phosphorus) and K (potassium). Each of these elements helps plants in different ways. Nitrogen spurs vigorous, leafy green growth and is an important nutrient for turf grasses. Phosphorus is important for strong root growth and flowering, and potassium enhances overall growth – both of roots and plants.
Once you understand the purpose of the three key nutrients, it’s fairly easy to choose the right fertilizer for your plant needs. If your goal is a healthy, green turf you’ll see that lawn fertilizers have an N-P-K ratio with the first number (nitrogen) much higher than the other two. Soil usually provides enough phosphorus and most of the potassium healthy grass needs, so the numbers for those nutrients are low.
Just remember not to overfeed – numerous studies have found that a spring and fall feeding coupled with deep watering are enough to keep the lawn looking great. Leave the grass clippings on the lawn since as they decay, they provide additional nitrogen. I love to see the clover blooming in my lawn since they are another excellent source of nitrogen. Use the nitrogen that nature is providing and save time and money.
Vegetables need nitrogen, but for the plants to flower and give a large harvest you’ll need to feed them more phosphorus and potassium. That’s why the second and third numbers are highest in products specifically for vegetables.
Flowering bulbs depend on phosphorus for healthy roots, so bulb fertilizers have a high middle number. You can also feed plants like your lilies with what’s called a balanced fertilizer such as 10-10-10, to deliver a balanced N-P-K designed for all-round garden health. I feed my daylily bed in early spring with 10-10-10 so that the lilies have lush foliage and lots of bloom by July.
Be sure to follow the instructions on the label carefully, especially early in the season when overfertilizing can cause “burning.” Most fertilizers should be worked into the soil around the plant rather than applied directly to the foliage. However, there are some liquid fertilizers that can be applied directly to the plants via spray.
Another choice is whether to use an organic or inorganic fertilizer. The major difference is that the organic fertilizer is less processed and usually has more micronutrients than does the inorganic fertilizer. Some examples of organic fertilizers are bone meal, manure and compost. The nutrients in the organic fertilizer will break down more slowly than those in inorganics and need to be applied less often. They also contain microorganisms that help to improve the soil texture over time, leading to better plant health. The initial cost of organics may be higher, but since fewer applications are needed the cost difference becomes pretty much equal over time.
By understanding the basics behind fertilizer labels, you can choose the right products for your lawn and garden goals with confidence.