The natural nutrients for all plant growth are normally found only in soil. When a major nutrient such as nitrogen, phosphorus, or potassium is deficient, any plant may soon show signs of discolored foliage, stunted growth, or paltry flowering. Trace elements such as iron, boron, zinc, copper, and magnesium, while not needed in large amounts, are also essential to best growth. An in-depth soil analysis can determine what is missing as well as suggest what chemicals to use to correct the imbalance. Nitrogen is essential for stem and leaf development. Phosphorus is for root enlargement and expansion. Potassium is for flower and fruit production. Since nitrogen is easily dissolved both by repeated rainfall and by mechanical irrigation, it needs to be replaced more frequently than phosphorus or potassium. Manufactured products are available in either a quick-acting chemical form or a slow-acting organic formulation. Always follow the manufacturer's instructions for application exactly. Distribute the fertilizer evenly -- never in clumps. Scratch it lightly into the top surface, and follow with a thorough watering to start the fertilizer into a useful solution. Excess amounts of water-absorbing, dry fertilizer left to nature's erratic rainfall schedules can damage delicate feeder roots at the surface of the soil. Fertilizing established perennials is usually recommended at the start of spring growth, yet many spring bulbs benefit from feeding right after blooming ends in order to stimulate stronger budding for the next season's leaves and flowers. Newly divided perennials, having reduced root systems, are best left unfertilized until they show definitive new growth. Excerpted from Gardening with Perennials Month by Month by Joseph Hudak All rights reserved by the original copyright owners. Excerpts are provided for display purposes only and may not be reproduced, reprinted or distributed without the written permission of the publisher.
