If you have a lawn and want to protect Lake Tahoe’s water quality, one of the most important things you can do is avoid over-fertilizing. Fertilizers can leech into the ground water and eventually become runoff into the lake causing algae growth that affects our water quality and clarity.
Fertilizer is prohibited in the backshore and in stream environment zones basin-wide. However, in other areas on your property where fertilizer may be needed to help plants become established, your help is needed.
The best times to add phosphorus to the soil is just before planting – especially with transplants. Use composts and organics as amendments to the soil, as these have good levels of available phosphorus for plants to use. Be sure to monitor phosphorus and pH levels in your soil to make sure you are not applying more than what is needed. You might want to consider having your soil tested annually.
In fact, soil experts tell us that Tahoe soils have plenty of available phosphorus and adding phosphorus does nothing to improve the vitality of your plants and lawn. When using fertilizer check the N-P-K ratings on the back of the container. This will tell you what percentage of the product contains phosphorus. Phosphorus is always the middle numeral in the N-P-K rating, demonstrated in the photo to the right. To help reverse the declining water clarity in the nearshore, take the following simple steps:
• Use ZERO-PHOSPHOROUS fertilizer. Talk to your yard maintenance professional before applying any fertilizer to your property. If you are purchasing your own fertilizer, look for a “O” in the middle of the formula as shown in the photo to the right.
• Don’t over fertilize. The spring and summer growing season in Lake Tahoe is short, only lasting about 5 months, and doesn’t require multiple applications of fertilizer. Once in the spring when planting and done!
• And remember, never apply fertilizer in the backshore or stream zones!
For more information on phosphorous free fertilizers visit: http://tahoebmp.org/FertilizerPhosphorus.aspx