How To Grow Grass Under Cedar Trees

Cedar trees (​Cedrus​ spp.) — an evergreen that reaches heights of 60 to 80 feet — tend to have the iconic "Christmas tree" shape with lower branches sweeping the ground. However, cutting away the lower branches can open up the landscape and give you more room to play in a small yard. The only drawback is the ring of barren land now visible under the cedar tree. Growing grass under your cedar tree may prove difficult, unless you understand the microclimate you're working with, choose a suitable type of grass and give the grass proper care.

Cedar trees create a microclimate around their trunk where few plants can thrive, primarily because of root competition. This helps the cedar as a large plant win the competition for water and nutrients in the soil over smaller plants such as grass. But from a homeowner's perspective, it can make the yard look sad and dead, not lush and vibrant. Understanding the growing conditions under a cedar tree can help you select the best grass to plant there.

The first thing to note is the dense shade under a cedar tree. Most grass types require full sun to grow in a thick, luxurious carpet, so it's important to find a shade-tolerant grass seed.

Next, it's important to understand that evergreen trees — including cedar trees — are very thirsty. Their extensive root systems will quickly draw in available water, which means any grass expected to grow underneath a cedar tree should also be drought tolerant or frequently watered.

According to Pennington Seed, the best shade-tolerant grass is fine fescue (​Festuca​ spp.). Fortunately, fine fescue grass also does best in soil with a slightly acidic pH of 5 to 6.5. Fescues are also drought tolerant, which means this grass meets all the criteria for growing under a cedar tree.

Specific types of fine fescue include Hard Fescue (​Festuca brevipila​) Chewings Fescue (​Festuca rubra​ subsp. ​commutata​), Creeping Red Fescue (​Festuca rubra​), and Sheep Fescue (​Festuca ovina​). There are slight differences among these cultivars in terms of color and germination speed. In general, all fine fescues grow slowly, which reduces the need to mow.

The only catch is that fine fescues are cool-season grasses, and they grow best in USDA zones 3 through 7. A shade- and drought-tolerant warm-season grass is Zoysia (​Zoysia​ spp., zones 5-10).

Sometimes it's possible to get away with throwing some grass seed on the ground, watering it now and then and reaping the rewards a few weeks later. But when you're growing grass in a less-than-ideal situation — like under a cedar tree — don't skimp on the prep work. Aerate the soil, add fertilizer, sow the seeds at the recommended rate for a bare patch of soil (versus for overseeding), keep the area well-watered and prevent kids and dogs from trampling the seedlings. With the proper grass selection and prep work, it's definitely possible to grow grass under a cedar tree.