Hello, Over the years my once full grass has withered away in areas and given way to a particular type of weed. I cannot identify it from the pictures on the web, but I'm sure you all can. As for my grass (what's left of it) it is patchy. The ground is hard. Does it require lime? Aeration? Top soil and over seeding? We live in Clarksburg, MD (Montgomery County).The grass is in part shade in some areas and full sun in others. The area that struggles is in part shade. As for the weeds, I began to notice them about 2-3 years ago. They have gotten steadily worse over the years. I fertilize my grass typically once, in the early spring with Scott's Turf Builder. I would like to know the following: What is this weed? How do I get rid of it? What can I do to get my grass to come back? See my pictures that are attached. Thank you.
The weed in your lawn looks like chickweed, a winter annual. Seeds germinate from late summer through fall. Weeds overwinter and continue to grow in early spring. Control with a broadleaf postemergent herbicide http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/non_HGIC_FS/TT%2049%... when the weeds are actively growing in the spring. You can also control both with a preemergent applied in early to mid-September before it germinates. However, you would not be able to sow grass seed in the fall. Hand pull or mow soon to remove the seedheads before the plants mature. This one-time bagging of the clippings is recommended
Your lawn looks compacted and looks like it requires some renovation. The best time is late summer through mid October. Grass sown now needs to be able to make it through the stresses of summer. You can test your soil now and results will give pH, liming, and fertilization recommendations. The best time to fertilize is in the fall. http://extension.umd.edu/hgic/soils/soil-testing
The best type of grass to sow is turf type tall fescue for full sun to part shade. Your lawn looks compacted and there is a lot of competition for moisture and nutrients from the tree roots and lack of sunlight which is why the grass is not thriving. You will have to decide how you want to renovate the backyard. You have the option of lightly mulching around the tree roots and planting some shade perennials. This will also prevent lawn mower damage to the trunks. You can core aerate and seed the lawn areas not affected by tree roots. See our publication on lawn renovation and overseeding http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG102%20Lawn%20Estab...http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG102%20Lawn%20Estab...