From the Maryland Cooperative Extension:
1. Take a soil test every 3 to 4 years. Fertilize according to soil test recommendations. Use less than the recommended amounts listed on fertilizer packages.
2. Leave grass clippings on your lawn (grasscycling.) They are a source of nitrogen for your lawn and will not contribute to thatch build-up in fescue or bluegrass lawns.
3. Home gardeners tend to over-fertilize flower and vegetable gardens. Reduce or eliminate fertilizer applications in well-established beds if organic matter is being added each year.
4. Don’t fertilize trees and shrubs if they appear healthy and are making adequate shoot and leaf growth.
5. Compost plant residues or incorporate them directly into soil. Discard plants with serious disease problems.
6. When appropriate, substitute slow-release fertilizers for those that are highly soluble and substitute locally available organic fertilizers (well-decomposed farmyard manure, backyard compost and municipal leaf compost) for manufactured chemical fertilizers.
7. Keep fertilizers off hard surfaces. Rain water will carry fertilizer salts into storm drains and surface waters and contribute to nutrient pollution of our waterways.
8. Over time, rainfall causes bare soil to erode and become compacted. Keep bare soil covered with a mulch and plant ground covers in areas where turf won’t grow. Plant winter cover crops in vegetable gardens – like oats, winter rye and crimson clover.
9. Avoid excessive foot or equipment traffic to prevent soil compaction, especially when the soil is wet. Construct terraces for beds on sloped ground. Keep soil in raised beds framed with solid sides.
10. To melt winter ice, use calcium magnesium acetate (CMA), potassium chloride (KCl), sodium chloride (NaCl) or calcium chloride (CaCl2). Do not use urea, potassium nitrate, or other chemical fertilizers containing nitrogen or phosphorous. The salts in these fertilizers may burn the foliage and roots of adjacent plants and wash into and pollute waterways.
Authors : Jon Traunfeld, Regional Specialist, Home and Garden Information Center, Maryland Cooperative Extension
Reviewers: Patricia Steinhilber, Ph.D., Nutrient Management Coordinator, Maryland Cooperative Extension and Judy McGowan, Nutrient Management Specialist, Maryland Department of Agriculture
12/03; revised 9/05; 2/09