stressed plants

How To Care For Them

By Nick Boulton

So what do those three numbers on fertilizers mean and how do you know what your plant needs? Keep in mind it’s important to plant healthy plants to start with, but fertilizing bushes, plants and trees provides additional nutrients that the surrounding soil may be lacking. Using fertilizer on young and newly transplanted bushes quickens their growth and a bush’s ability to establish itself into the landscape. Fertilizer can also help bushes with slower growth begin to sprout once again. All plants produce their own food through photosynthesis and the application of fertilizer provides the very important and necessary ingredients and elements to help promote healthy, vigorous growth. In a forest, some of these elements are present in the soil since the debris from trees and plants are constantly falling off of other plants and trees and biodegrading into the soil providing nutrients to plants and trees. Within our yards, city and surrounding areas, we are constantly cleaning this debris up and not allowing it time to biodegrade into nutrients for our plants.

Most complete fertilizers are a mixture of three elements - nitrogen (N), phosphorus (P) and potassium (K), represented by a series of three numbers, such as 18-18-18. The numbers will tell the percentage of each element in the package by weight. So, an 1818-18 fertilizer would contain 18 percent each of nitrogen, phosphorus and potassium. A 16-4-8 would contain 16 percent nitrogen, 4 percent phosphorus and 8 percent potassium. A fertilizer with 8 percent nitrogen and no phosphorus or potassium would read 8-0-0. You can really get into what each plant is going to need more of. Such as what to give a plant that blossoming compared to a plant that is just trying to stay green, or what to give a tomato plant to get large tomatoes to produce. Nitrogen is the element most used by plants and is extremely important for healthy plant growth. Phosphorus promotes photosynthesis and healthy root growth, and potassium assists with water retention and disease resistance.

Just as you would test the water in a pool or spa before applying chemicals to it, it’s important to test the soil pH before randomly picking fertilizer to ensure the fertilizer will be effective. A soil pH between 6.0 and 7.0 is the optimum level for the bush to absorb and draw nutrients from the fertilizer. A high or low soil pH may make the fertilizer ineffective or possibly toxic to the plant, which would in turn kill the plant. A soil test will determine if any changes need to be made before fertilizing. The best time to fertilize is in early spring as growing is beginning, or in Fall once the active growing period of plants have finished.

There are several types of fertilizer that can be used. Some of these are Water-Soluble, Granules, and Natural Fertilizers.

Water-soluble

Water-soluble blends are dissolved in water prior to application similar to sugar in your ice tea. The nutrients will surround the plant when poured into the soil. Typically this can cost less than slow-releasing versions. The downside of water-soluble nutrients is that it can be lost quicker through the soil with just a few inches of rain water or additional watering, thereby not providing as much nutrition to the plant as hoped for.

Granules

Granules or slow-release fertilizers provide ongoing nutrition throughout the season because the granules release nitrogen and other elements over time. By placing the granules in a wide circle around the bush it will slowly work it into the soil around the plant. As rainfall or regular watering occurs, the bush receives little amounts of fertilizer.

Natural fertilizers

Natural fertilizers such as compost, manure or vegetation can provide a slower rate than other fertilizers and they also provide many of the little elements that plants benefit from such as iron or zinc. The nitrogen, phosphorus and potassium levels tend to be lower in natural fertilizers, requiring more applications than other fertilizers. The benefit, however, is that natural fertilizers aid in improving the overall soil condition and can be added to the soil at any time. As well as it is a more natural way to supply your plants with the fertilizer that they may need.

Poor plant growth is not always a sure sign of a need to fertilize. Planting in the wrong location, too much sun, not enough sun, overwatering and under watering can all cause growth issues such as yellowing or fewer leaves than usual, limited twig growth or dying. Before fertilizing, try to determine if there is an underlying issue and then correct the issue of the plant performance. In addition, fertilizing during periods of stress may cause further harm to the plant. Never fertilize when plants show signs of stress, such as scorched or drooping branches, and do not apply any fertilizers during a period of drought unless the bush is well watered. Fertilizing when conditions are dry may cause root, stem and leaf damage if water is not consistently available and could in turn ultimately kill the plant.

If you still are not comfortable with doing this yourself, Lawn Doctor here in Southern Utah offers tree and shrub fertilization feedings to all your trees, plants and shrubs. With their help you can get the necessary “food” that they may be lacking for the right times of the year.