Native Plants

Q. Who is Mr. Smarty Plants?

A: There are those who suspect Wildflower Center volunteers are the culpable and capable culprits. Yet, others think staff members play some, albeit small, role. You can torture us with your plant questions, but we will never reveal the Green Guru's secret identity.

Help us grow by giving to the Plant Database Fund or by becoming a member

Did you know you can access the Native Plant Information Network with your web-enabled smartphone?

Ask Mr. Smarty Plants

Ask Mr. Smarty Plants is a free service provided by the staff and volunteers at the Lady Bird Johnson Wildflower Center.

Search Smarty Plants

See a list of all Smarty Plants questions

Please forgive us, but Mr. Smarty Plants has been overwhelmed by a flood of mail and must take a break for awhile to catch up. We hope to be accepting new questions again soon. Thank you!

Need help with plant identification, visit the plant identification page.

rate this answer

1 rating

Thursday - April 03, 2008

From: Staten Island , NY
Region: Northeast
Topic: Shrubs
Title: Dwarf evergreen shrub for windowboxes in Staten Island , NY
Answered by: Barbara Medford

QUESTION:

Dear Mr. Smarty Plants, Could you recommend a dwarf evergreen shrub, not deciduous that also has pretty flowers that would thrive in a container in the northeast...area would have sun for about 4 -5 hrs per day. Is there a small evergreen that would survive in window boxes all year here? Something that would look great all year round? Any suggestions would be appreciated. Would also like to string white lights on front lawn tree all year round...do you know of a resource where I could purchase commercial quality, low voltage lighting? Thank you very much

ANSWER:

Last question first, electricity stuff is WAY our of our line. We try to ignore electricity altogether, hoping it will work and not bother us. You can probably find a good selection at any of the big home improvement stores, that seems to be the sort of thing they carry a lot of.

Your other request, for year round evergreen shrubs that will thrive in a container, is difficult. It's a little hard to tell from this USDA Plant Hardiness Zone Map for the Northeast U.S., but it looks like Staten Island is in Zone 5a, which means you will have average minimum temperatures of -15 deg to -20 deg. While we may be able to find some evergreen shrubs that could, with careful pruning, remain in a windowbox for some time, remember that when a plant is in the ground, its roots are insulated by the whole Earth. When it is in a windowbox, they are insulated with a few inches of potting soil. In very low temperatures, covering the plant will do the roots no good. If the roots freeze, the plant dies. We found precisely two shrubs that are considered evergreen in New York, Gaultheria procumbens (eastern teaberry) and Ilex opaca (American holly). Neither of these will necessarily stay in bounds or permit pruning that would keep them small. There are a few conifers that stay evergreen there, but they have long, deep roots, and could not survive in a container.

We would refer you again, as we did the last time you wrote, to The Cornell University Department of Horticulture website on Trees and Shrubs for more local information.

Gaultheria procumbens