Heuchera and Astilbe in the shade of trees

by Jane
(Camden East Ontario)

I have several heuchera and astilbe which have been growing in the shade of a pine tree and a maple tree for about three years.

They have expressed their displeasure at this situation by becoming progressively smaller each year. I have tried digging around them to break up the small fibrous roots of the pine tree, digging in several inches of manure, adding lime to the heuchera, mulching lightly with straw, watering every couple of days but still they stubbornly refuse to grow. Any other suggestions?

Doug says - move them. Pine are too dense shade for growing plants like Heuchera. And too competitive root zones for water-loving Astilbe. You've picked the two toughest trees to garden under so unless you're prepared to add lots of compost and lots of water to this area and even trim the trees to give the plants extra light, you're fighting a losing battle. Move them to a space where they get a touch more light and better growing conditions.