Yew trees are evergreen hardwoods that grow in temperate to cold climates. They are smaller evergreens with branching, multi-lobed foliage. Unlike pines that only need fertiliser when they are yellowing or wilting, yews can benefit from regular fertilisation whether or not they are healthy. In fact, proper fertilisation can help your yew trees thrive and flourish even through the cold season.
Fertilise your yew tree or shrub in mid-May after the first rush of new growth. Fertiliser applied before the new growth is formed could be washed away by heavy spring rains, especially if the ground is still partially frozen.
Observe your yew tree or shrub and note how far the longest branch stretches out. This marks the edge of the drip line, the area where water drips from the branches to the ground.
Drive a garden stake into the ground directly under the longest branch. Drive several more stakes into the ground every 3 feet in a circle around the tree, following the drip line. For a shrub, drive a second stake into the ground about a foot away from the first stake and use the second stake to create your circle. This ensures that the fertiliser reaches the outer edges of the tree's or shrub's roots.
Use a shovel to scoop small piles of evergreen fertiliser in a 3-foot wide circular band outside the drip line. Most root endings extend beyond the drip line; fertilising outside of the drip line ensures the fertiliser reaches these root endings. Evergreen fertilisers usually contain peat moss or pine bark to help keep the soil acid.
Rake the piles of fertiliser into an even 1-inch layer. Water the area until the ground is very wet but not soggy. Mulch with a 1-inch layer of pine straw to help the water and fertiliser sink into the soil. Remove the garden stakes if desired.