by Charlene Burgi
| April gardening in the sunshine
April weather can be disconcerting at best. One day the sun draws us out into the garden to weed, complete last-minute pruning, fertilize or set out seedlings. Then the next day torrential rains drive us right back into the house.
This past weekend was no exception, as rains thwarted the best of intentions to tackle weeding before the weeds take over the garden. The ground was still too cold and saturated here in Lassen to set out seedlings. But the weather worked for applying fertilizers—in fact, I was able to take advantage of the rains to help deliver the rich nutrients down into the root systems.
The first question when pursuing this task is always: what type of fertilizers to use, if any at all? Should you choose granular or liquid? Time released? Organic or inorganic? And what is with all those numbers on the fertilizer package?
Did I just say the weather was disconcerting? Books have been written on the subject of fertilizers. Many gardeners have their favorite formulas, brand and timing for application. This gardener is no different. I prefer using organic fertilizers—either manufactured by my chickens, donkeys or horses, or purchased fertilizers made from various manures, plant or animal matter. I also look for fertilizers rich in nitrogen (N), phosphorus (P) and potassium (K). The numbers following the NPK on the packaging represent the percentage of each nutrient in the mix. You will note that they never add up to 100%. The remainder is other nutrients and fillers. I prefer fertilizers in which these are as organic as well, as there is less chance of burning the plants than with inorganic fertilizers. In addition, organic products help eliminate salt build-up—especially in potted plants.
I also like to control the amount of nitrogen, phosphorus and potassium going to specific plants at different times of the year. For example, nitrogen contributes to the growth and greening of plants, but makes for weak stem growth. Fertilizers high in nitrogen are used to achieve lush green lawns. On the other hand, spring flowering plants benefit from getting a 0-10-10 fertilizing during the winter months to aid in their flower/fruit production. While dormant, they do not need any nitrogen for growth (note the 0 in that 0-10-10 formula). However, in spring I can easily switch to 15-30-15 to feed roses, rhodies, camellias and azaleas, along with other flowering shrubs and fruit trees.
You might be wondering what those last two macronutrients do. If nitrogen accounts for green fast growth, phosphorus aids in overall health of the plant by stimulating and developing strong roots and flowers. Potassium is responsible for creating overall vigor and further development of carbohydrates in photosynthesis.
The right ratio of these three elements offers a well-balanced diet to your garden. However, to complicate the issue, if your soil is already high in phosphorus or potassium it could be detrimental to your plants that do not need large amounts of these macronutrients to survive. The best way to determine the specific needs of your plants is to purchase a soil test kit at your local garden center. This can help determine if you should omit one of these elements when fertilizing. For example, if you have soil already abundant in phosphorus, you can purchase a fertilizer with a 0 (P) in the numeric formula.
Fertilizers: They are a study in themselves. What better thing can you do on a rainy day but to pick up some more detailed literature on the subject? Your plants will thank you for it!