top of page

To Fertilize or not to Fertilize. That be the question.

In their natural habitats, Trees, Shrubs & Plants rarely display signs of nutrient deficiency because the natural recycling of nutrients occurs through the decomposition of fallen leaves, twigs, branches and other organic materials. They’re well adapted to growing in their native regions and therefore, need little or no human intervention to survive. This is their ideal life.

The modern garden landscape, however, is an artificial habitat for most non-native trees and shrubs. The soil conditions may be vastly different than what they are genetically adapted to and diminished nutrient recycling as a result of planting schemes (layouts) or maintenance practices (collection of leaves in spring/fall) call for periodic applications of fertilizer to the soil directly beneath them.

Every good soil fertility program should begin with a soil test that identifies the pH (acidity) levels on a scale from 0-14. Soils with a pH below 7 are acidic while those above 7 are alkaline. Nutrient recycling best occurs within a pH range of 6 & 7. At the extremes of this range, many nutrients occur in forms that are unavailable for uptake by plant roots. So close, yet so far. Identifying the pH means we can make adjustments to suit the specific plants, shrubs and trees.

Sometimes, Limestone is used to adjust pH levels higher and Sulphur to adjust it lower. However, these materials need to be worked into the soil at a minimum depth of 8” to be effective. Surface application is not enough and may scar the topsoil irreparably.

All plants, shrubs and trees require an uptake of essential 16 mineral elements most commonly Nitrogen, Phosphorous and Potassium. Research has shown that Nitrogen yields the greatest growth response in trees and shrubs. For this reason, high nitrogen fertilizers are recommended for established woody plants.

Application of slow-release fertilizers provide the most efficient use of these nutrients because root growth and nutrient absorption can occur anytime soil temperatures are above 5° C. Slow release is preferred over their quick release, water-based fertilizers because they provide more nutrients, more slowly, resulting in uniform growth. Nutrients are also more readily absorbed through the soil rather than the foliage.

A great catch-all way to ensure that your plants, trees and shrubs are well-fertilized throughout the season is to ensure they have at least 2-3” of natural, compost blend mulch to feed on. This type of mulch is different from decorative blends which may contain rubber, plastics, or artificial material which does not decompose or feed the surrounding soil. We only use the best compost blend mulches that are locally produced so not only are you helping your plants grow, you’re helping the local economy grow as well!

Bonus tip – When preparing your gardens for the fall, have a thick layer of fall leaves and shrub trimmings in the bed. This adds a natural layer between your precious plants and the icy Canadian winters but also as the material degrades, it will provide a slow drip of nutrients to the beds

24 views0 comments

Recent Posts

See All


bottom of page