Question: Is this a good time to fertilize my landscape? I am confused by the wide variety of different fertilizers. What type of fertilizer do you use?

Answer: Now is a good time to fertilize all the existing plants in your landscape. I also fertilize anytime I plant new plants. Although there are many specialized fertilizers available, I use two types of granular fertilizer for almost all my outdoor plants. I use lawn fertilizer for my lawn, trees and shrubs, and a general purpose fertilizer for flowers and vegetables. Woody plants only need one fertilizer application per year. Lawns need at least two applications. Some flowers and vegetables also need a second application, especially container plants.

I prefer a 3-1-2 ratio of nitrogen-phosphorus-potassium for lawns. A 3-1-1 or 4-1-1 balance is also acceptable. Check the active ingredients label, usually found on the bottom or back of the bag. Most lawn fertilizers contain 15% to 20% nitrogen. So a 3-1-2 balance could be 15-5-10 or 20-7-14. Organic fertilizers will have a lower percentage with about half as much fertilizer. It is also important to have a small percentage of iron (1% to 3% or less is enough).

Since nitrogen is the most soluble of nutrients, it is also desirable if at least part of the nitrogen in lawn fertilizers is the slow release or timed release type. This is often accomplished by poly coating or encapsulating the nitrogen pellets. This allows the nitrogen to be released over a longer period, reducing the need for frequent applications. Organic fertilizers are naturally slow release.

Although many tree and shrub fertilizers have different nutrient balances, I have found that 3-0-2 lawn fertilizer works equally well and sometimes better.

General purpose fertilizers usually contain about a 1-1-1 ratio of nitrogen- phosphorus-potassium. Typical is 12-12-12 or 16-16-16, with organic fertilizers more like 6-6-6. These ratios do not have to be exact, just so there are approximately equal amounts of the three major fertilizer nutrients. Micronutrients such as iron, zinc and manganese are also beneficial.

Flower and vegetable fertilizers are typically 1-2-1 ratio, such as 5-10-5 or 6-10-4. I have found that general purpose fertilizers work equally well as flower and vegetable fertilizers.

General purpose fertilizers are also available in a coated or time-release type. All of the fertilizer is coated and not just the nitrogen. They release fertilizer gradually over several weeks. Osmocote is the most popular brand. I use it for all my containers and sometimes in flower beds.

I occasionally use liquid and soluble fertilizers for more immediate effect on plants that are not doing well. Most of them have ratios of about 1-1-1. If used alone, they must be applied frequently since they are quickly leached below the root zone.

Allen Wilson can be contacted at allenw98663@yahoo.com.

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