Here it is, next week already and we are talking about shady spots. You decided on a grass for your lawn and prepared and fertilized the soil.
Now your grass seed has taken root and rewarded you with a light fuzz of green. Time to look to the area under those trees.
My No. 1 solution for a single tree that makes dense shade? Landscaper fabric and macadamia nut shells. The fabric covers the ground preventing weeds and the
covering of nut shells keeps the rain from pounding the soil and washing it away. It also guarantees that the roots of the tree will not have to compete with other roots for nutrients. Start the fabric about a foot (30 cm) from the trunk and extend it out as far as the grass. If you don’t care for the nut shells, try using crushed rock. You might use the nearly white stone available to brighten up the darkness under the tree. Whatever you choose, make sure to put down about two inches of material.
Once the fabric and nut shells are down, you have a choice. You can put a border around the area with rock, brick, or some other material to keep the nut shells in place or you can put in a border of plants that are shade tolerant, or both. You might decide to continue the green of your lawn right up to the nut shells. In that case, ferns are a wonderful choice for the area. If you prefer to make a complete break from the green, a variegated liriope (mondo or monkey grass, ophiopogon japonicas) is an excellent choice to outline and define the space. Liriope is also slow growing and non-invasive, unlike some other choices. Ivies, for example, will start to creep both into the lawn and onto the nut shells, sometimes within days of planting, and that can be a nuisance.
There are other choices, of course. I have seen lovely areas surrounded with begonias and they are impressive. You can probably find wild begonias by fence lines on your property and transplant them or you can visit your local vivero for a wider choice. In partial shade, the Rex begonia develops colorful red and light green foliage to go along with its flowers so it looks wonderful even when not blooming.
So, choose your grass seed or sod wisely, try to stay away from a lawn in dry areas, and make good use of shady areas. Your yard is going to look wonderful.