My lawn has large bare patches, what can I do?

Are those bare patches recent or have they been there for a while? Because depending on the cause (fungus, pests, soil compaction, lack of watering) the treatment changes quite a bit.

First thing is to figure out what's wrong. If the soil is hard as a rock and barely drains water, it's probably compaction. In that case you need to aerate the area with an aerator or even dig a bit to loosen the soil, then rake well to clear out the dead stuff and seed with quality grass seed. If you see dark areas or kind of slimy-looking spots, it could be a fungus, and then you need to stop watering so much and improve air circulation (cut the grass short so air can flow through). Pests like beetle larvae are easier to spot because if you lift up a patch of grass you'll see white bugs.

Once you've identified the problem, fixing it is straightforward: prep that area well by clearing debris and dead matter, add fresh soil if needed, seed and keep it moist (but not waterlogged) for about three weeks. Some people use a mix of peat and seed so it takes better. Patience - grass takes its time filling in those bare spots. And while you're at it, check if you're watering evenly or if there are areas getting less water; sometimes bare patches show up just because some parts of your lawn get less water than others.

The truth is, before you dig into investigating the cause so much, you should check if those areas are getting enough water! A lot of bare patches are just from neglecting watering, especially in spots where the sun hits direct and the soil dries out super fast. Once you make sure the watering is solid, that's when you look into fungus and pests if nothing changes.

What nobody mentions before you start investigating causes is that if you seed those bare spots without properly preparing the soil first, it's going to fail anyway. You need to scrape away the dead area, loosen the compacted soil, and only then put down new seed or sod. Once you've done that, consistent watering is key - a couple of weeks without water and you'll lose it all over again. If the bare spots have fungus or pests, you'll notice it because the surrounding soil looks off or the remaining grass is yellowing; in that case you do need to treat it specifically. But in most cases it's a combination of poor soil prep and irregular watering.

If you've got large bare patches, what really works is starting by aerating those areas well before doing anything else. A dethatcher or even a sturdy rake to remove compacted dead matter is step zero, because the soil underneath is packed down and no seed is going to germinate there. Once you've loosened the soil a bit, only then can you think about the rest.

What we all overlook is that many times those bare patches aren't just from watering issues or a one-off pest problem, but from a combination of several things: soil compaction, poor drainage, and yeah, lack of water in summer. So after aerating, it's time to topdress - throw down a layer of quality substrate mixed with sand to improve drainage - and then you seed or lay down small patches of sod. The important thing is keeping it moist without waterlogging it for the next two or three weeks, which is when it's establishing roots.

If the bare patches stick around after that, then yeah investigate whether there's a recurring problem: maybe that area gets a lot of foot traffic, or it drains poorly and fungi take advantage of the standing moisture. But most of the time, prepping the soil correctly solves the problem without needing to go around looking for culprits.