planting over existing underground utilities

Asked May 1, 2013, 1:04 PM EDT

We have a bare area about 5x20 feet, next to the street and paralleling our driveway, that needs re-planting. (Neighbors recently needed to remove several big shrubs here near the property line.) The tricky thing is, our electric/gas/sewer lines are buried underneath this area. We've dumped 8-10" of compost over the ground but are not sure what to safely plant. We'd like to put in a smallish tree(s) and some shrubs. Can you recommend varieties that don't have monstrous roots, like full sun, and don't need much summer water? Good fall color would be great. Also, we don't want anything so massive that it'd be hard to see when we drive in or out. We're in West Linn, zone 8. Thanks for any suggestions.

Clackamas County Oregon

4 Responses

Thanks for your quetion. First, do you know how deep the lines are buried? It might be a good idea to contact your utility company to find out before you begin digging. Shrubs might be better than trees in this circumstance because their roots tend to grow more at surface area than trees. I would start with attractive sun-loving shrubs like rock rose (Cistus sp.) that produce colorful flowers and are drought tolerant. After a few years, they may need to be trimmed back a bit--the ones available at nurseries can grow larger. To prune, you would just shape them at the edges with a clipper--no need for anything fancy. Other possibilities are orange or variegated forms of Spirea that will maintain a mounded shape but fill out the space over time, or even the smaller forms of andromeda (Pieris sp.). Pieris is evergreen but the new foliage can be very colorful. All are drought tolerant, once they become established. You could add to that some low growing flowering perennials like the native Oregon iris (Iris tenax) with bright blue flowers, or the Mediterranean sunrose (Helianthemum sp.) with flower colors ranging from white and yellow to pink, orange or red. Japanese or dutch iris would be other suitable choices. I hope this provides you with some alternatives. If you need more suggestions or feedback on particular plants, please let me know. Good luck. Linda

Thank you, Linda--I hadn't thought about Cistus and Helianthemum but those are great ideas.

One more question for you: A church nearby has rugosa roses in their parking lot. They're in two long dividers, 100 feet or more, and make a beautiful big hedge. Do you think a rugosa type rose shrub might work in our situation? Thanks.

Yes, rugosa roses will work well too. They also can get quite large, so plan to prune them. I personally prefer mixed plantings, but you should do the kind of planting you are most comfortable with. Linda

I'm with you, mixed plantings usually look best. I'll have to look for a smaller-growing rugosa, perhaps. Or if that doesn't work I can just drive a couple miles up the road and admire the church's rose hedge!

Thanks again.