Growing grass in full shade isn’t easy. In fact, it’s impossible! Grass, like all plants, need sunlight for photosynthesis. However, there are several steps you can take to grow grass in partial and dappled shade sections of your garden.
A natural competition
Grass and trees are competitors- they both need sun, water and nutrients. Lack of sunlight will cause your grass to thin and become stunted, and make it easier for disease, weeds and pests to move in. If you are hoping to establish grass under a tree, the first thing to do is to assess how much sunlight reaches the ground each day. Watch the amount of sun available to the section. If it’s less than a total of three or four hours in the day, there really isn’t much point trying to establish grass.
Trim the trees
If the total amount of sunlight isn’t enough to sustain grass, one option could be to cut back the tree to allow more dappled light through. Depending on the species and size of the tree, removing limbs, thinning out the canopy or giving the densest parts of the tree a prune will all make a difference. And removing branches also benefits the tree, by enhancing air circulation to the center of the tree which improves overall health.
Eliminate foot traffic
When grass is already struggling to deal with shade from trees or buildings, you want to remove any extra stress you can, such as what is caused by traffic (people and pets). Think creatively about how this might be done. You might want to:
- Create a path or walkway through the grassed area
- Place a garden bed around the base of the tree
- Place feature rocks in the shadiest areas
- Use bark chips, pine straw or wood chips in the most densely shaded spots
Pick the right grass
Your climate, the soil you are planting and seasonal variations will have an impact on your chances of success. The soil under trees often becomes acidic, so you might want to do some soil testing before you settle on a particular grass type. Once you know what type of soil you are working with, you can prepare the soil as recommended before seeding. It also pays to know if the cool-season or warm-season grasses do better in your area.
Shade tolerant grasses – St Augustine
There are several varieties of the St Augustine grass available, most of which adapt well to dappled light. Our recommendation is the Palmetto which adapts well to sandy soil and has been proven to do ok in soils that retain a lot of moisture. The Palmetto, Seville and Sapphire varieties will require a minimum of 4-5 hours of direct sunlight a day.
Shade tolerant grasses – Zoysia
This turf-like grass is often used on golf courses and playing fields because it can handle more traffic and wear than many other kinds of grasses. It is a shade-tolerant species that do better in the warmer and more tropical states. It has fine blades, deep green color and a shiny appearance.
Others Shade tolerant grasses consider
On top of St Augustine and Zoysia, some other shade-tolerant grasses that are available are:
- Rye Grass
These grasses tend to prefer full sun, but with proper care, they will grow in part in shady areas of your garden.
Planting grass from seed
There are two steps you can take when planting grass seeds in shady areas, that can help you achieve a decent patch. The first is to over-seed each fall, making sure your grass has a good shot at achieving a density that will help sustain it over time. Aim for between 6 – 8 lbs of grass seed per 1000 square feet to get your grass off to a good start. The second step is to use mixed grass seed. This also improves your odds of achieving a nice dense lawn, which can tolerate a wider range of tough conditions.
The blades of grass are like little solar panels- they collect the sun that the grass needs for growth. If you mow too short, you will be removing some of the overall amounts of grass that can be used to gain nourishment. Set your mower blades to mow a little higher than you would normally to encourage maximum sun access for the individual blades.
Don’t make these mistakes when it comes to dealing with grass in shaded areas:
- Don’t replace sunlight with nutrients- it is possible to add many nutrients and treatments to grassed areas. Grassed areas need one half to two third less nitrogen than sunny lawns. Nutrients are not a replacement for sunlight!
- Don’t replace sunlight with water- it might be tempting to pour more water on grass that is struggling. Water is not a replacement for sunlight!
- Grass that is growing in shaded areas has less chance to dry out when it is wet. During prolonged rainy periods, your grass may be constantly damp, which can actually lead to fungal diseases. Treat any disease you notice as soon as you can.
- Don’t let the weeds take hold! If weeds are getting into your grass, remove them as soon as you can, and where possible limit herbicide on already stressed grass.
Ornamental grass options
It might be worth considering growing the taller and more ornamental grasses in the toughest spots on your yard. These ornamental grasses will grow fast with variegation and natural diversity and will add some structure, shape and color to wide sections of the shaded yard. Some of the best to consider are:
• Mondo grass
• Berkeley sedge
• Japanese forest grass
• Korean feather reed grass
• Northern sea oats
• Mosquito grass
The bottom line: Your grass needs sunlight to survive. There are steps you can take to help grass that is growing in the dappled and low-level sun. You really need to watch how much sun is available, make good decisions about which grass to use and be prepared to think a little creatively when it comes to garden design.