Linden trees, known botanically as Tilia americana and more commonly as basswood or lime trees, are hardy deciduous trees. They are prized for their large size up to 70 feet in height, white- or butter-hued spring flowers, and lush canopy of large medium-tone green leaves. Linden trees possess a large, wide root mass extending out by 2 1/2 times the height of the tree, are heavy feeders and are not drought tolerant.
Determine if your linden tree requires fertilizer by assessing the new green branch growth each year. If there is more than 6 inches of growth without fertilizer, fertilizer is not likely needed. Fertilizer is warranted ff there is less than 2 inches of new growth each year. Conduct a soil analysis test if in doubt about growth and the nutrient content of the soil.
Feed your linden tree once a year, or every other year, as needed, in the spring after the soil has thawed and can be worked readily. This is commonly in April or early May.
Cast a slow-release complete fertilizer formula with a guaranteed analysis of 18-6-12 around the tree. Start a foot out from the trunk and extend out in a wide circle equal in distance to at least twice the height of the linden tree. Apply 1/2 lb. of fertilizer for every 100-square feet of soil expanse around the tree.
Work the slow-release fertilizer granules into the top few inches of soil with a rake or cultivating fork.
Water the soil immediately after fertilizing, drenching the soil to a depth of at least a foot down to drive the nutrients into the soil.