Repairing Weak Spots
Every lawn will have its own strong and weak areas and sometimes for one reason or the another, weak spots will develop needing the attention and the repair. Most of the healthy lawns should usually repair themselves given the proper time and nurture, however in some cases that may not be enough.
Pet damage (urinating on the lawn, digging and clawing as well as faeces, seeds or other debris that may invite other pest and rodents that damage your lawn) as well as larger pests such as moles, gophers, etc. can cause the damage to certain areas of your lawn. Furthermore, insects, mold, disease, excessive moisture or dry spots on your lawn may damage the lawn past the point where it can repair itself. When that happens, you may want to repair those weak or damaged areas to aid the lawn in recovery and repair process.
Reseeding: Larger damaged and weak spots may require reseeding. Reseeding involves mixing the grass seeds with soil and compost and applying over weak or damaged areas. The care should be taken to investigate as to why the weak or damaged spot has appeared and removing or remedying any apparent issues that may have contributed to it (disease, drainage problems, pet urine damage etc.).
Once the problem that has contributed to the weak spot development, has been remedied effectively the repair of the damaged area can commence by applying seed and compost mixture as a thin layer covering the damaged area. With proper time and care of newly reseeded area (water at regular intervals, keep traffic, pets and other factors that can damage newly seeded area further, etc.) the new lawn will develop and blend with the existing turf, therefore, repairing the damaged area.
Turf Patching: Alternatively, if you want more immediate result or the damaged area cannot be protected adequately from traffic and pets, you may opt to replace the damaged or dead area with freshly cut sod plugin or patch, therefore, speeding up the process of regrowth and repair of the damaged or weakened area on your lawn.