If fertilizers are improperly applied, the nutrients they contain will bypass the plants they are intended for and end up in downstream waters where they stimulate the growth of another plant, algae, spoiling the crystal clear beauty of Lake Tahoe. Do not routinely apply fertilizer when it may not be needed. Have a good reason for using it. Plants exhibit symptoms of specific nutrient deficiencies. For instance, the most common symptoms of N shortage are a general yellowing of older leaves and poor growth.
Young leaves remain green.
Phosphorus deficiencies commonly appear as a reddish color along the edges of leaves and next to the veins. Deficiencies of K are not as obvious, but may show up as mottling on leaves and poor growth. Growth reduction is another symptom that may not be apparent unless there are healthy plants nearby. Sierra Nevada soils are typically not deficient in K. Plants native or adapted to the Tahoe Basin and the Sierra Nevada will not need fertilization and in fact may be harmed by it. Fertilizer Selection In Nevada and California, fertilizers are regulated by State Law.