Would you be surprised to learn that soil conditions in urban environments are inhospitable to trees? That’s right. An urban growing environment is vastly different than the ideal conditions found in nature.
Trees growing in urban soils often have small, yellow foliage, which indicates a nutrient imbalance.
Compacted soil, restricted root zones, and competition with turf for nutrients are just a few of the stresses urban trees are under. These challenges are particularly common on commercial properties due to heavier foot traffic, more buildings and pavement.
Unable to access the nutrients they need, trees will struggle. They grow more slowly. Their foliage is smaller and off-color. Leaves die and fall unseasonably. Insect and disease problems occur more frequently.
The best autumn advice for healthy trees is this: get a soil test! Find out now what is, and isn’t, in the soil where your trees and shrubs are living.
Even though it’s mostly hidden underground, the soil is not a mystery. It contains macronutrients – nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur – as well as micronutrients like iron and zinc. These nutrients are necessary for plant growth, but not always present at appropriate levels. Further, certain soil conditions like texture or pH level may make it difficult for plants to access those nutrients that are available.
Nutrient levels and soil characteristics will vary from site to site, and may even differ on the same property. The only sure way to find out about the soil on a specific property is through a soil test. A soil sample is collected from beneath the trees or shrubs and analyzed to determine exact nutrient levels, pH level, organic matter present, and nutrient retention capacity.
Tried and Tested
If you fertilize without a soil test, it’s very possible you’ll see no results. Not only will you waste your investment, but worse, you could harm soil or plants in the landscape through misapplication. Add certain nitrogen fertilizers to a plant with aphids or mites and your infestation may escalate. Create an imbalance of nutrient levels and see your turf suffer as it competes with trees to uptake what’s available.
With soil testing, specific nutrient deficiencies, as well as problems with pH level or amount of organic matter present, can be identified. That means fertilization and soil amendments can be tailored to effectively address problems instead of squandering money and creating new issues.
Timing is Key
The results of a soil test combined with horticultural knowledge provide precise, scientific data that can be used to improve plant health and appearance – if soil treatments are timed correctly. Autumn is an ideal time for this work to be completed because two vital needs can be addressed at once: (1) nutrients aren’t needed for new foliage growth in autumn or winter so trees and shrubs can instead use those nutrients for root development and (2) excess nutrients can be stored so that they are immediately available when the next season’s spring growth begins.
When you have the right information, you can make the right decisions. Soil testing provides that information and should be prioritized on commercial landscapes in the upcoming season.