Conscientious gardening is doable for all

The warm weather has tomato plants blossoming, lawn mowers raging, and weeds rising.  While exercising your green thumb this summer and fall, make sure your garden isn’t negatively impacting water quality.

Excess nutrients like nitrogen and phosphorus threaten the health of Lake Pend Oreille and other local waterways.  Sources of nutrients include excess fertilizers, soil that enters storm water runoff, and yard waste. 

With a little extra effort you can drastically reduce or eliminate the impacts your lawn and garden have on water quality.

Before applying synthetic or organic fertilizers, test nearby soils every three to five years to make sure your plants even need the additives. Soil test kits are available at the University of Idaho Extension Office; for a modest expense you can learn about what will make your tomatoes plump and juicy. 

Lawns and gardens need a certain amount of nitrogen, phosphorus, potassium, and other nutrients to grow their best.  Once soil has achieved this benchmark, the remainder will join storm water in future rain events.  This runoff will take these nutrients to surface or ground water.  Please fertilize wisely.  When applied at the wrong time or over applied, fertilizers can create salt problems, affect winter hardiness, exaggerate pest problems, and make plants grow excessively.

When applying fertilizers, it’s a good idea to work them into the soil to prevent them from seeping during a storm.  When selecting a fertilizer, look for slow release or natural organic fertilizers.

Some things to look for on fertilizer labels include water insoluble nitrogen (WIN), controlled release nitrogen, sulfur coated urea (SCU), isobutylidene diurea (IBDU), urea formaldehyde (UF), or resin-coated urea to indicate slow release forms. 

Responsible watering and mowing practices will protect water bodies and conserve water. Most lawns and gardens require the weekly equivalent of one inch of rain.  Place a tin can in the garden to measure and avoid over watering.  Keep in mind that cool season grasses like fescues, bluegrasses and ryegrasses naturally go dormant in the summer and grow well in shoulder seasons.  Mowing at heights of 2.5-3.5 inches promotes a deeper drought tolerant and pest tolerant root system reducing erosion.

Yard waste and essentially all plant matter is also a source of nutrients that will fertilize waterways and terrestrial zones.  Dispose of these materials responsibly by keeping them away from surface waters. 

Mulching can help retain soil moisture, moderate soil temperature, and prevent erosion.  But mulching deeper than 3 inches will rob plants of moisture and encourage shallow root systems (especially harmful in drought conditions).  Don’t mulch with freshly ground organic materials.  Let them sit for 6 months or they will remove nitrogen from soil and cause your plants to yellow.

While not a full list of ways to reduce nutrient pollution, this serves as a good start to protect our waterways.  For more information, check www.tristatecouncil.org and remember a clean lake begins at your doorstep.

n John Sugden is the program director for the Tri-State Water Quality Council.