A proper fertilizer program is a very important component in a healthy landscape. With most new plantings we will add slow-release fertilizer tablets and 6-20-20 granular fertilizer. For planting in containers and for annuals we use Osmocote granular slow-release fertilizer, along with 6-20-20. (6-20-20 signifies 6% nitrogen, 20% phosphorus, 20% potassium. It also contains micronutrients).

Basically, nitrogen encourages growth and green leaves, phosphorus is important for flower, fruit, and root development, and potassium is akey to overall plant health. The 6-20-20 fertilizer is low in nitrogen and relatively high in phosphorus and potassium. This is why it’s an ideal starter fertilizer and fall fertilizer. We don’t want high nitrogen that will encourage tender new growth at those times.

New plantings go through a transition period when they’re removed from their containers and planted in a new environment. They need the right combination of growth and root development. Additionally, new plants get a small amount of organic nitrogen from the compost soil amendment we use. (The compost also has other components that benefit plant and soil health). The slow-release fertilizers probide a broad range of nutrients that become available for plant uptake over the course of several months.

Our approach to maintenance is that we want each plant to look as healthy and vigorous as possible. With this in mind, we apply 6-20-20 fertilizer in the fall around all plants that need better size, vigor, or color. We routinely fertilize all Roses, Rhododendrons, Camellias, Azaleas, Citrus and fruit trees.

In late February/early March, we apply a high nitrogen fertilizer to stimulate new spring growth. We use either 16-6-8 or 21-4-4 fertilizer on all plants and trees that need it. (Rhododendrons, Azaleas, and ferns will only get another application of 6-20-20–if anything–since they don’t perform well with too much nitrogen). These granular fertilizers get watered-in by the late winter/early spring rains. We use fertilizer injectors for drip systems where plantings require additional fertilizer applications during the growing season.

The fertilizers we use are inorganic, meaning they are derived from mineral sources. Organic fertilizers are deprived from plant or animal sources. The nutrients that are used by the plants (nitrogen, phosphorus, potassium and micronutrients) have the same molecular structure, whether they are organic or inorganic. The plants don’t know the difference. Inorganic fertilizers are far-less expensive than organic, are easier to apply, and are formulated with substantially-higher percentages of nutrients. (Therefore, less fertilizer needs to be applied to get the same results).

For new landscapes it is best to submit a soil sample for laboratory analysis. The sample is anlyzed to show nutrient and organic levels, pH, and recommended fertilizers and amendments necessary for optimal plant growth, at a cost of approximately $100. With this knowledge we will adjust our fertilizer program as needed.

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