Ian,<br><br>In Collingwood (zone 5a...in southern Ontario's snowbelt) we find that perennials tolerate snow better than shrubs as they don't get crushed. We've tried Rosa rugosa, False Spirea, and Gro Low Fragrant Sumac with no luck. Karl Foerster Feather Reed Grass has been extremely successful in a 1m median (irrigated) and curbside planting beds (not irrigated.) It is cut once a year in the early spring (cool season grass that greens up early) so we have the benefit of the grass in the fall/winter.<br>
<br>As for trees, we had moderate luck with honeylocust in a 1m x 1m x 1m tree vault (the road engineers designed the vaults and we came in afterwards to 'green things up.' Covering the canopies with burlap over winter (not an easy job) improved the survival rate. The ones that survived their first year seem to be doing (relatively) well 4 years later.<br>
<br>Inspired by the Quebec City Urban Forestry Conference tours, we recently tried planting one of the Dutch Elm Disease resistant elm cultivars in a boulevard (zone 4.) After the first winter there was 100% survival for the elms and serviceberry (A. canadensis), if you can believe it. Honeylocust was third. Red oak (native to the area) did terribly. We don't know if it was stock from a warmer seed zone or if the red oak is just not able to tolerate that much salt and snow (trees were often buried in 2m snowbanks.) Anyway, I'd try the elm in in a median if I were planting trees.<br>
<br>Finally, I've noticed that if trees are tall enough to have some of the canopy above the salt spray, they seem to pull through. We planted four freemani maples in a boulevard. As you may know, they grow almost too fast and the stock at planting was very tall. The lower canopy was killed off by the salt but the rest of the canopy seems to be doing OK...again about 4 years later. <br>
<br>Alison<br><br>Alison Bond OALA CSLA<br>Landscape Architect and Certified Arborist<br>Envision-Tatham<br><br><div class="gmail_quote">On Mon, Mar 23, 2009 at 4:48 PM, Ian Wilson <span dir="ltr"><<a href="mailto:IWilson@kelowna.ca">IWilson@kelowna.ca</a>></span> wrote:<br>
<blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
<div>
<div><span><font size="2" face="Arial">I'm looking for
information on low-maintenance plant materials and landscaping designs for road
or highway medians that have "stood the test of time". I just got a copy
of the new "Planning the Urban Forest" book and saw a photo of
an interesting median planting in Urbana, Illinois utilizing native plants,
which got me thinking about what other cities might be using for
medians.</font></span></div>
<div><span><font size="2" face="Arial"></font></span> </div>
<div><span><font size="2" face="Arial">The City of Kelowna
has been developing more medians in recent years. We've tried a variety of
different designs and plant materials. Medians seem to be among the most
difficult growing sites in terms of maintenance and plant health. Here's
some of the challenges that we have had:</font></span></div>
<div><span><font size="2" face="Arial"></font></span> </div>
<div><span><font size="2" face="Arial">1) Getting enough soil volume for trees and plants,
particularly in narrower medians</font></span></div>
<div><span><font size="2" face="Arial">2)
Salt spray due to winter road maintenance in our climate. Some trees
suffer bud dieback due to salt spray. Others might suffer soil toxicity
once the salts get too high. One of the best trees we've found so far
seems to be red oak.</font></span></div>
<div><span><font size="2" face="Arial">3) Sand
accumulations in the planting bed. Even if you have a nicely mulched bed,
after a year or two it all ends up looking like a bed of
sand.</font></span></div>
<div><span><font size="2" face="Arial">4) Worker
safety in order to maintain median plant materials and remove garbage and
maintain irrigation etc.</font></span></div>
<div><span><font size="2" face="Arial">5) Landscaping
medians on highways with higher speeds - the additional wind and salt spray etc
seems to be particularly hard on plants when the traffic speeds are
higher.</font></span></div>
<div><span><font size="2" face="Arial"></font></span> </div>
<div><span><font size="2" face="Arial">We have several
different designs that we have tried, depending on situation. We're
starting to move towards a couple of different designs, one is more of a
xeriscape design with trees in a large planting bed and xeriscape plant ground
covers (where we have the space). Where speeds are higher and sand and
salt accumulation is an issue we're trying more hardscape with trees in "pits"
and hard surfacing, but unless we use Silva cells or something similar we
run into the challenge of limited soil volumes.</font></span></div>
<div><span><font size="2" face="Arial"></font></span> </div>
<div><span><font size="2" face="Arial">Anybody have some
good designs or ideas that they'd like to share?</font></span></div>
<div><span><font size="2" face="Arial"></font></span> </div>
<div><span><font size="2" face="Arial">thanks,
Ian</font></span></div>
<div> </div>
<div align="left">
<div align="left"><font size="2" face="Arial">
<div align="left"><font face="Arial"><font size="2">Ian Wilson<span>, RPF, Certified Arborist</span></font></font></div>
<div align="left"><font face="Arial"><font size="2"><span>Park Services Manager</span></font></font></div>
<div align="left"><font size="2" face="Arial">City of Kelowna</font></div>
<div align="left"><font size="2" face="Arial">Park Services</font></div>
<div align="left"><font size="2" face="Arial">Civic Operations</font></div>
<div align="left"><span><font size="2" face="Arial">1359 KLO
road,</font></span></div>
<div align="left"><span><font size="2" face="Arial">Kelowna,
BC V1W 3N8</font></span></div>
<div align="left"><font size="2" face="Arial"><a href="mailto:iwilson@kelowna.ca" target="_blank">iwilson@kelowna.ca</a></font></div>
<div align="left"><font size="2" face="Arial">Phone: (250) 469-8842</font></div>
<div align="left"><font size="2" face="Arial">Fax: (250) 862-3335</font></div>
<div align="left"> </div>
<div align="left"><img alt="BestBlooming" src="cid:403182520@23032009-0DAD" align="left" border="0" hspace="0"></div></font></div>
<div> </div></div>
<div> </div></div>
</blockquote></div><br>