It's never advisable to plant around your AC units. They need proper air circulation to perform at their optimum. Planting around them can actually increase the workload on them and raise your electric bill. Worse case scenario is that the unit can overheat due to lack of adequate air circulation.

Barb

Thank you Barb, it's a good point.
Natalie

In Texas we are mostly trying to shade our AC units from blistering afternoon sun, so some have put up a lattice screen around theirs that allows for air circulation but does disguise them for the most part. Don't put it too close to the unit, and be sure to build it in a way to allow access for maintenance.

I have hosta around mine. they still allow air flow. but, they are bare in the winter also.

I am trying to figure this out too. Our AC faces directly west next to a brick wall, yup hot! I was advised against any bushy bushes, due to the air flow issue. Now I wonder if just some clematis or other vines against the wall will dress up the space.

Can you plant a tree nearby to shade them?

I planted dwarf boxwood around mine, taking care to place them where there would still be room for airflow around the unit and between the boxwoods, even when the shrubs reached their mature size. Also, the boxwood can be clipped back in case I made a calculation mistake. I don't think the shrubs will ever hide the unit, but it does move the eye from the unit to the greenery.

Andee,
I really like the look of neatly cut boxwood - reminds me of a formal english garden. At this point there is tall hosta and cannas doing their temporary job that will be history in a winter time. I would like to have "bones" there, that distruct attention from the metal all year long.
Thanks for the idea!
I love this forum - wish I could have all of you guys over for tea/coffee, garden conversation and company of mind-like friends.
~Natalie

I have put two trellis at an angle to each other to hide the AC. There is some small space between the two trellis and I put them far enough away from the AC as to not to block air flow.

I covered one trellis with Clematis and the other with vineing Nastursium. In the winter the AC is buried by the snow.

Snow is a great cover up for AC units. We get snow here in GA infrequently. I grew up with tons of snow in winter and miss it.
I like the idea of trellis - allows the air to circulate.
Nasturtiums are such happy flowers. This is a first year that I am growing them, and they get so tall to my surprise. Don't know if they are climbers, will see. So far they look very bright and healthy despite of the drought.
Thanks Bud_wi!
~Natalie