by Lisa Watters-Lain, Arizona’s garden gal
When walking down the fertilizer aisle at Watters Garden Center or any home improvement store you can’t help notice the dizzying the array of plant food. You’ll see bags and bottles, powders and granules, sprays and concentrates. Furthermore, you’ll discover an increasing number of organic and “earth-friendly” plant foods. Which one is best for a healthy landscape? To pick the best plant food, you must make sense of a few plant nutrients first.
Your native evergreens appreciate a balanced fertilizer or plant food. For the vegetable, or flower gardeners a complete fertilizer is necessary to supply plants with the three major elements they require to thrive:
Nitrogen (N): Promotes healthy foliage and leaves.
Phosphorus or Phosphate (P): Stimulates root systems, bud, and vegetable growth.
Potassium or Potash (K): Promotes stronger stems and aids in flower (and fruit) formation.
The fertilizer label will list the nutrients in the order of NPK, with numbers representing the percentage of nutrient compared to filler ingredients. For example, Watters 7-4-4 All Purpose Plant Food contains 7% nitrogen, 4% Phosphorus, and 4% Potassium. Filler ingredients are inert materials that add weight and volume to make the plant food easier to spread. For example, limestone, sawdust, and clay are used in powdered formulas, and water enhances liquid fertilizers. Fillers also add micronutrients like iron and sulfur to the mix for increased plant health and increased color.
Flower fertilizers like Watters Flower Power 54, 10-54-10, usually have a more significant percentage of phosphorus compared to other ingredients. Healthy flowers start with a vigorous root system, and a phosphate boost ensures your flowers get a good start.
Chemical Fertilizers are inexpensive and widespread, but what are they?
Fertilizer manufacturers like Scotts, Miracle-Gro, Vigoro, and Ironite create artificial fertilizers by combining inorganic chemicals to form compounds like ammonium nitrate or magnesium sulfate. An advantage of chemical fertilizers is that rapid-growing plants take up their nutrients quickly, sometimes too fast.
Disadvantages include the risk of over-application, which causes burning, and the absence of any soil-improving qualities. Chemicals have a negative potential for drinking water when misused. The chemicals are released so rapidly they can taint your drinking water. Earth Friendly organics are far safer.
Spring, Summer, and Fall are the best seasonal dates to apply plant foods to the landscape. Local gardeners use Easter, July 4th, and Halloween as timely holiday markers for best application dates.
Foliar fertilizers are liquid nutrients that plants absorb through their leaves. Not all vegetable and flowering plants feed this way efficiently because the wax and hairs on the leaves act as a barrier to nutrient uptake, and as a result, the plant cannot receive the needed nutrients. However, some nutrient deficiencies are addressed quickly by using foliar fertilizers. Potassium is one readily absorbed nutrient in a foliar feeding application, so foliar fertilizers are appropriate for treating potassium deficiencies.
If your flowers are exhibiting signs of chlorosis, yellowing of the foliage, your plants may have an iron deficiency. Another situation where the rapid results achieved by foliar plant foods are useful.
Two Week Intervals are best when using liquid, or water-soluble plants food in the garden. This pattern brings out the most fragrance and color of blooming plants.
Organic Fertilizer Benefits
Organic fertilizers come from living things like barnyard manure, fish emulsion, and leaf mold, and from non-living material like rock phosphate and greensand.
Fertilizers from organic matter not only supply essential nutrients to your plants, but they also improve soil strength and texture. Even gardeners who don’t eat what they grow still appreciate organic plant foods because they:
Don’t burn plants
Strengthen plants’ immune systems
Are non-toxic to beneficial insects and wildlife
Remain active in the soil for extended periods
If a soil test reveals a deficiency of one primary nutrient, you can purchase a pure fertilizer, which contains only nitrogen, phosphorus, or potassium as a standalone ingredient. Simple fertilizers can be chemical or organic in makeup like organic bonemeal 0-10-0.
Best Advice – I’m a gardener who believes in organic plant foods because they are safer for us humans, our pets, and the wild animals that enter our landscapes. Feed everything in the landscape three times per year with Watters 7-4-4 ‘All Purpose Food,’ including container gardens and raised beds. Best application holidays to apply by are Easter, Independence day on July 4th and Halloween.
Ask for my free handout here at Watters Garden Center for those that want to go deeper into the 4 Steps of Proper Plant Food.
Until next issue, I’ll be helping readers with plant foods here at Watters Garden Center.