With Spring almost here plants are starting to grow and will need “food”, just like we do.
Where you live will determine when to begin your spring fertilizer program. Incline Village and Truckee will need that application within a couple weeks. Tahoe City and the West Shore will be another month or so. A good indicator of the right timing is when the last snow has melted.
It is important to understand what nutrients your plants need. It is best to have your soil tested to determine what is missing. This way you won’t be wasting unneeded nutrients and your hard earned dollars. The soil analysis will tell you what is in the soil and recommendations to correct any soil problem you may have. Contact a soil lab for details, or my office.
What nutrients are required?We all remember chemistry class and the nutrients nitrogen (N), phosphorous (P) and potassium (K). There are 17 other elements that are needed for proper plant health. Most of these are found in the native soils.
When you buy a fertilizer (synthetic or organic) you will see the N-P-K numbers on the front of the bag. These numbers tell you how much of these nutrients are in the bag, AS A PERCENT OF THE WEIGHT OF THE BAG. Example- a 40 pound bag of 12-3-5 has 4.8 pounds of nitrogen (12 %), 1.2 pounds of phosphorous (3%) and 2 pounds of potassium (5%). Keep these numbers in mind when your recommendations say to apply “2 pounds of nitrogen per 1,000 square feet”. You should apply 16.66 pounds from that 40 pound bag. Not 2 pounds.
Why are these nutrients necessary?Nitrogen is used up quickly by the plants and can move through the soil profile. Nitrogen helps with “top” growth of plants. Phosphorous helps with root system development and seedling growth. Phosphorous binds tightly to the soil particles and doesn’t move very much. (Not true when sediment and erosion occur. Phosphorous can relocate into the lakes and streams this way.) Potassium helps with disease resistance, drought tolerance and doesn’t move very quickly through the soil.
How do the nutrients get into the plants? Fertilizers break down with moisture and soil microbes to become available to the plant roots. Slow release fertilizers are recommended for a longer lasting effect, are better for the environment and are more economical. Since organic fertilizers are broken down by microbes above certain temperatures, it may take a bit longer to see the result with these. Still a better choice for the environment and building the soil profile at the same time. Less salt build up also.
How often do I have to fertilize my planter beds?If you are using a slow release product you can expect to apply the fertilizer to the soil twice a season. Early spring and then again after the heat of summer. The fall application provides needed sugars that the plants store over the winter for spring wake up.
Stewardship  Having researched our local soils, and sent many soil samples to the lab, I have learned that the primary nutrient needed in the Truckee/Tahoe area is nitrogen. Phosphorous and, to a lesser degree potassium, are sufficiently present for most plant growth. When you are shopping look for a product that has a ratio of approximately 3-1-2 for the N-P-K. Best if you can use a low phosphorous product.  The second number (P) on the bag.
Again refer to your soil test for your specific recommendations.