Not Wood Chips Or Pine Straw: The Best Type Of Mulch To Use Around An AC Unit

Mulching around your AC unit is important. If you don't stop plants from growing too close, dropped leaves and pollen can end up clogging up delicate fins and filters, compromising your unit's efficiency. Not only that, but nearby pollinator-friendly plants can end up attracting unfriendly insects, like wasps, which have been known to nest inside outdoor AC units. The problem that some homeowners run into with mulching is that they simply use the wrong type. Things like wood chips and pine straw are fairly lightweight, meaning they can be sucked up inside the unit, creating blockages and damaging the delicate internal parts. Not only that, but if your unit isn't suitably raised off the ground, those materials act like sponges and retain lots of water against the unit, which can also lead to damage.

It's generally best to mulch the area around your AC unit with something inorganic and weighty. River rock and gravel are both good options. These will stay put on the ground and can suppress unwanted garden growth. You can choose them in a variety of sizes and colors, too, meaning that if you're not planning to conceal your AC unit, you can at least improve its aesthetics. Oh, and don't forget, whereas pine straw and wood chips degrade after just a couple of seasons, rocks don't. In other words, provided that you follow some basic (but important) pointers, they should serve you well for decades with minimal, if any, maintenance.

Firstly, whether you opt for river rocks or gravel, make sure you buy enough to prevent sunlight from passing through it, which encourages grass and weeds to grow. A depth of two inches should be sufficient. It can also pay to get rid of any garden weeds around your AC unit before laying your stones, to further reduce the chances of growth. And, if you're really serious about it, it can't hurt to lay down some weed-proof landscape fabric before you place your rocks or gravel.

Bear in mind, too, that you'll need to allow for at least two-to-three feet of clearance around your AC unit. Even if you manage to successfully suppress weeds and grass from growing around your unit, you'll still need to have your system serviced and maintained from time to time. If there isn't enough clearance around the unit, your technician may struggle to gain the access to it.

Finally, while there's little maintenance involved with rock or gravel mulch, it's still important to keep an eye on it for unwanted growth. Soil can easily blow from elsewhere in your garden and settle on your stones, allowing weeds to take root. With that in mind, inspect the mulched area regularly, and clear it of any large debris, like twigs and leaves. If you notice a build up of soil, you could try to clear it with a leaf blower or garden sieve.