Organic Fertilizers for a Pine Tree
Pine trees (Pinus sp.) are hardy evergreen conifers that have varying characteristics and growing requirements, depending on the species or cultivar of the pine. For example, the Japanese umbrella pine grows in U.S. Department of Agriculture Hardiness Zones 5 through 9. Pines are hardy trees that require little maintenance and generally no fertilization. However, adding an organic fertilizer to the pine tree can help improve poor soil and give the plant a nutrient boost.
According to University of Minnesota, pine trees should be given a complete fertilizer with nitrogen, phosphorus and potassium. The nitrogen content should be slightly higher than phosphorus and potassium levels; 10-8-6 is generally recommended for pine trees and shrubs. The first number in the analysis is nitrogen, the second is phosphorus and the last number is potassium. Furthermore, consider performing a soil analysis test, which will inform you what nutrients your soil is lacking, what type of soil you are dealing with and whether it is acidic or alkaline. Evergreen plants generally grow best in more acidic soils with decent organic content.
Manure is a common organic fertilizer that comes from various sources, including cow, horse, poultry and bat guano. Cow manure has an average NPK level of 0.6-0.2-0.5 and adds nitrogen to the soil. Horse manure adds a small amount of nitrogen, phosphorous, and potassium at an analysis of about 0.7-0.3-0.6. Poultry manure has a higher level of nitrogen with an analysis of 1.1-0.8-0.5 and should be composted before applying to the pine, since the high level of nitrogen can burn the tree. Bat guano is the feces from bats. It adds both nitrogen and phosphorus and helps stimulate the microbes in the soil. If the guano is processed for a higher level of nitrogen, the analysis is 10-3-1. If the guano is processed for a higher level of phosphorus, the analysis is 3-10-1. Each type of manure has its own recommended usage instructions that you should follow for best results. However, general directions for manure are to spread it on the soil around the pine moving outward to the tree’s drip line. Incorporate the manure into the soil with a garden fork and dampen the area with a water hose.
Composts are aged organic materials, such as decayed plant matter. When added to the soil, compost adds vital nutrients and organic material to the soil. Compost is either aged or unfinished and can be made at home in your compost pile or purchased at garden centers. Unfinished composts should never be used on pine trees or other plants with active roots and can be identified by its ammonia-like odor. Only compost that is aged or seasoned should be applied to established pine trees. Use compost in the spring before new growth appears by adding a 3-inch layer around the entire pine tree. Avoid piling compost against the trunk and water thoroughly after the application.
Compost tea is essentially “brewed” using water and a bag or sacked filled with organic compost. A burlap sack, pillowcase or pantyhose works well for the bag or sack. Whichever you choose, fill it with about two shovelfuls of compost and secure the end of the sack or bag closed. Set a large container that has a lid on a level surface and place the compost-filled bag inside the container. Add water to the container at a ratio of 5 parts water and 1 part compost, and cover the container with its lid. The compost tea will need to brew for about 7 to 10 days undisturbed. After the allotted time has passed, remove the lid and add water until the liquid achieves a light brown tint that resembles tea. When ready to use, transfer the compost tea to a pump sprayer and mist the pine foliage or its soil with the compost tea.
Organic mulch added around the pine tree helps to keep the moisture and nutrients in the soil but it also helps insulate the pine’s roots protecting them from temperature fluctuations. Any organic mulch works including shredded bark, wood chips or aged compost. A 2- to 3-inch layer of mulch should be added around the entire tree keeping it 2 inches away from the pine tree trunk and spreading it out a few inches from the tree branches. You can water and fertilize the tree by applying the liquid directly over the organic mulch.
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