Fertilizers for Container Gardens
Grow Healthy Plants With Nitrogen Phosphorous and Potassium
Plants in container gardens need fertilizers to thrive while growing. Fertilizers that contain nitrogen, phosphorous and potassium are good for growing healthy plants.
Understanding Garden Fertilizers
A percent number system is used to represent the amount of nutrients found in a fertilizer. For example, 10-5-5 would mean that the fertilizer contains 10 percent nitrogen, 5 percent phosphorous and 5 percent potassium, sometimes called potash. Each of these nutrients contributes to growing healthy plants:
- Nitrogen encourages growth of stems and leaves on a plant. Too much nitrogen will kill a plant or discourage flowering.
- Phosphorous stimulates flower and fruit production and root development. Plants will use less amounts of phosphorous than nitrogen.
- Potassium provides protection from disease, helps the plant efficiently use water and strengthens a plant against stresses such as drought or extreme temperatures. A plant will use lesser quantities of potassium, as well.
Basic Container Plant Fertilizing
Gardeners fertilize plants in container gardens more often than in garden beds. The repeated watering container gardens need, especially during hot summer days, washes away nutrients faster. Outside, container gardens grown in a drought situation will take up less fertilizer.
Indoor, container gardens will require fertilizing more frequently during spring and summer months. When plants go dormant, such as during winter months, they will use less nutrients.
In general, annual and vegetable plants use more fertilizer than perennial flowers and groundcovers. Apply fertilizer only when soil is moist to avoid burning the plant.
Slow Release Fertilizers
Slow release fertilizers come in, what looks like, tiny beads. When mixed in potting soil, the beads will gradually release fertilizer as the plants are watered. Some gardeners will start the growing season with this type of fertilizer. Later in the season, gardeners may add a series of liquid plant fertilizer treatments to the watering schedule. Some potting soil mixes include a slow release fertilizer; it is a good idea to check the package label before adding more.
Liquid Plant Fertilizers
Liquid plant fertilizers are sold in concentrated form. The directions will indicate to add a measured amount to a specified quantity of water. Gardeners will dilute, by half, the amount of liquid fertilizer when using it in combination with a slow release fertilizer. A plant will benefit from a weaker solution of liquid fertilizer but applied more often.
As stated earlier, plants should be fertilized when the soil is moist. Soil less potting mix in container gardens is especially susceptible to drying out.
Organic Fertilizers
Organic gardeners use packaged fertilizers made with fish emulsion, seaweed or microbes put into a slow release, non-burning bead. Homemade manure or herbal teas are other garden fertilizers to try. Whether organic or inorganic, plants take up the same amount of nutrients needed to grow healthy.
Over time, fertilizer run off has polluted many communities by excessive nitrogen, phosphorous or potassium entering into the groundwater or soil. First, gardeners should rely on growing healthy plants by improving garden soil with organic matter. Then add appropriate amounts of fertilizer for the plants’ needs. Container gardeners can follow the same principle by using fresh potting soil every season for outdoor containers and repotting indoor plants every one-two years.
