Most trees and shrubs get all the nutrients they need from soil and mulch. But annual plants, vegetable gardens and lawns sometimes need extra nutrients.
Go Organic and slow release!
Natural organic or slow-release fertilizers provide nutrients in small amounts over time - just the way your plants need them! Quick-release fertilizers are highly soluble, and water and rain can wash them right down the storm drain - directly into local waterways where nitrogen causes algae to grow, depleting oxygen and suffocating aquatic wildlife.
N = nitrogen, P = phosphorous, K = potassium
Nitrogen, phosphorous and potassium are three major nutrients that are important for the growth of healthy plants. All plant food (fertilizer) needs to have a healthy balance of nutrients.
In the Pacific Northwest, the optimum ratio of N, P and K is three parts nitrogen to one part phosphorous to two parts potassium: 3N-to-1P-to-2K.
Don't over fertilize
Plants need only small amounts of nutrients. Applying more fertilizer than what the label recommends will NOT make plants greener or healthier. Stick to the amount called for on the label, if not less!
When to Apply
Vegetables, perennials and ornamentals have different fertilizer needs. Product labels and county extension services are good sources of information.
Lawns are best fertilized in the fall; this builds up nutrient reserves in the grass. If you fertilize twice a year, feed once in late May and then again in the fall. But remember, May and June are heavy grass-growing months, especially if we have a lot of rain, and the lawn also is using the reserves it has built up over winter. Be prepared to mow! Learn more… (PDF, 142 K).
Updated: Jun. 3, 2011