Choosing the best tree fertilizer spikes begins with identifying the specific requirements of a tree and the particular characteristics of the surrounding soil, as these factors determine the type and concentration of plant nutrients that will optimize tree growth and health. The size, shape, and composition of tree fertilizer spikes varies from product to product, has an impact on the speed with which fertilizer enters the soil, and needs to be taken into consideration when shopping for fertilizer. Certain consumers may also wish to consider natural or organic tree fertilizer spikes, primarily for ethical or environmental, rather than strictly practical, reasons.
All plants require large amounts of water, air, and sunlight to grow. They require nutrients, principally nitrogen, phosphorous, and potassium, but also many trace minerals and nutrients that are critical for healthy growth. Ideally, these nutrients are found naturally in the soil, but in many cases, the level of nutrients available in the soil is insufficient for optimal plant growth or the balance of nutrients is off for a particular species of tree, and fertilizers, such as tree fertilizer spikes, must be employed.
When choosing tree fertilizer spikes, the first step should be to determine the level of nutrients in the soil and to compare that level to the requirements of the specific tree being fertilized. Home soil assay kits can offer some insight, and professionals at a reputable local garden center can often provide general advice on the characteristics of soil in the region. Tree fertilizer spikes should be chosen to complement the makeup of the local soil. Most fertilizers are rated using three numbers, which indicate the percentage of the fertilizer that is made up of nitrogen, phosphorous, and potassium, respectively, with the remainder of the fertilizer made up of inert agents.
Tree fertilizer spikes are generally made up of a nutrient mix encased in a biodegradable binder. As a rule of thumb, spikes with more surface area break down faster, although most spikes deliver their fertilizer content quite slowly. Their slow rate of breakdown makes spikes a very safe form of fertilizer, although they tend to be noticeably more expensive than other forms of fertilizer.
Some consumers may prefer to employ natural or organic tree fertilizer spikes. These fertilizers are often chemically identical to other types of fertilizer and rated using the same system. They are usually, however, produced through more natural methods, rather than through industrial processes, and this may reduce their overall environmental footprint.