We’re getting a lot of questions about which fertilizer to use and how, when and how much to apply, so here is some information that I hope will help you. I will admit that I am not a consistent applicator to my trees and shrubs in the ground, but I am very good about my container plants – they depend on me, you see.
How to fertilize hanging baskets and containers – here at Watson’s we fertilize our hanging baskets almost every time we water, but anyone will get good results by fertilizing once a week. Synthetic fertilizers such as Miracle-Gro are perfectly appropriate for annual containers and hanging baskets. If the container planting includes calibrachoa (“million bells”) or petunias, Miracid is a good choice, otherwise the Miracle-Gro Bloom Booster will work just fine. The normal mix is 1 Tablespoon per gallon of water. Containers should never be fertilized when they are very dry; dry planters should be watered well and fertilized later the same day or on the following day.
What fertilizer is best for container trees, like Japanese maples? – I really like the Dr. Earth Life fertilizer because it is pelletized and does not have to be worked into the soil. Its label says “Throw and Go” and that is exactly what I do. It is organic and slow release, so I apply it once a year only around mid-May to June.
What about plants in the ground? Dr. Earth Life fertilizer also works well for plants in the ground. If you have acid-loving plants such as rhododendrons, azaleas, camellias or blueberries, an acid mix, such as Dr. Earth’s Acid Lover’s fertilizer is best to use because its formulation makes iron more available to those plants. I do prefer organic fertilizers for plants in the ground because it makes the soil healthier as well as providing nutrients for the plants.
If you’ve always used Miracle-Gro for everything: Miracle-Gro and other synthetic fertilizers are like drinking a Red Bull – it’s a quick shot in the arm (or kick in the pants) and then it’s gone. Synthetic fertilizers dissolve quickly in water and some of it is taken up immediately by plants. The rest leaches away quickly. Synthetic fertilizers are also high in salts which can build up in the soil over time, which can kill beneficial organisms in the soil. Organic fertilizers release much more slowly and are available for a long period of time, so they do not have to be applied very often. Most organic fertilizers nowadays are loaded with beneficial bacteria and mycorrhizae that make the soil healthier and better for plants.
How to fertilize tomatoes: Again, I recommend a slow release organic fertilizer such as Dr. Earth Tomato and Vegetable food. A handful should be worked into the hole when the tomato is planted. After that, about once a month a handful can be worked gently into the soil around each plant. Synthetic fertilizers won’t hurt, they do supply nitrogen, phosphorus and potassium, but they generally do not have micronutrients and they definitely do not have the beneficial bacteria and mycorrhizae that can make soil nutrients available to the plant.