| There are a number of evergreen viburnums that tolerate stressful urban conditions very well. Some get very large, so check ultimate growth potential and space accordingly: Viburnum x pragense, V. rhytidophyllum and cultivars, V. x rhytidophylloides and cultivars. You can see mature specimens at the Brooklyn Botanic Garden. The leaves of evergreen viburnums droop in sub-freezing weather, like many rhododendrons do. Evergreen hollies are nice, and droopless, but our native Ilex opaca is not forgiving of conditions it doesn't like. You might want to try the so-called blue hollies, Ilex x meserveae. There are a number of cultivars. These hollies and the viburnums tolerate shade very well, but grow in full sun too. The previous suggestion of junipers is excellent, as long as they receive full sunlight. Also for full sun, a good pine is Pinus parviflora, Japanese white pine. It's smaller growing, yet similar to our native white pine, but it is tolerant of salt. Don't plant Japanese black pine, Pinus thunbergii. Gets so many diseases now it is unlikely to survive to maturity. Some people are reporting good success with a similar-looking pine, Pinus heldrechii var. leucodermis, the Bosnian pine, a dead ringer for the Japanese black, except it is smaller and slower growing, also somewhat salt tolerant. So far, it is proving resistant to the diseases that are devastating Japanese black pine (diplodia tip blight and blue stain fungus, spread by pine bark beetles). Evergreen euonymus, Euonymus kiautschovicus 'Manhattan', is commonly planted in NYC, but it now has a real problem with scale insects which tends to weaken it. I'd use something else, but it is still very popular. By the way, the name refers to the city of Manhattan, Kansas, where it was bred. Pyracantha is not dense enough for a good hedge, but it can give a lot of fall and winter berry color when used as an accent among the other evergreens. It's most beautiful if you have the space to let it grow wild and free. The carbon monoxide problem is fortunately not severe in the city, according to studies by Cornell University, because the air is not trapped, like in L.A. or Mexico City. Especially true along the Hudson River. Ozone can be more problematic for our trees and plants when it flares up. I'd say more worrisome are compacted soil full of construction debris, wacky soil pH, salt, strong winds, and high heat in summer from all the pavement reflection and absorption. Lack of drainage is also bad, but usually city soils are pretty well drained. You always want to loosen and amend your soil with compost. Beyond that, you are smart to look for plants that are adaptable. With all these horrors, we still seem to able to grow a lot of plants along our roadways. Good luck! |
