Answer: You have a real challenge on your hands! Grass won't thrive in shade. You can try the Shade Mixtures but you are just fighting a losing battle with Mother Nature. Grass - even the shade tolerant ones - needs a certain amount of sunshine in order to grow and be healthy. Fescue grass will tolerate shade better than most grasses. But in the deep shade, even fescue will need to be replanted each fall.
Three practices will help fescue survive in the shade but they might be counter-intuitive to you. First, mow higher in the shade than you would in the sun. You will maximize leaf surface on the grass. Second, fertilize less so the grass won't be forced to grow what it can't support. Third, water more (deeply, once per week) in July and August so the grass is not stressed.
If you combine these three suggestions with removing some of your nearby tree limbs, you might be pleasantly surprised this year. Otherwise, hoist the white flag of surrender and plant liriope, mondo grass, ivy or pachysandra in the deep shade.
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