Which fertilizer type is least harmful to newly planted ornamentals?

Slow-release fertilizers are the least harmful to newly planted ornamentals because they provide nutrients gradually over an extended period. This slow release minimizes the risk of nutrient burn, which can occur when plants receive a sudden surge of nutrients, particularly nitrogen, phosphorus, or potassium.

Newly planted ornamentals often experience stress as they establish their root systems. Slow-release fertilizers support this establishment process by ensuring that the plants receive a consistent supply of nutrients at a rate that aligns with their developing needs. This approach reduces the potential for over-fertilization and helps maintain soil health, promoting beneficial microbial activity.

Weed-and-feed fertilizers, while effective for weed control and providing nutrients, often contain high levels of nitrogen and are typically designed for established lawns rather than sensitive new plantings. High phosphorus fertilizers can be detrimental to newly planted ornamentals as they may cause nutrient imbalances and environmental runoff issues. Granular nitrogen fertilizers can also be too strong for young plants, potentially leading to root burn if applied excessively or improperly.

In contrast, slow-release fertilizers are formulated specifically for a gradual release, thereby ensuring that newly planted ornamentals receive the necessary nutrients they need without the associated risks of over-fertilization.