**I'm always looking for others to join in guerilla gardening in Manhattan or North Brooklyn. **
I would like to remind everyone in NYC about the seriousness of tree care and helping out the underfunded Parks Dept. as much as possible when out guerilla gardening. First off, it is massively ILLEGAL to prune (even if it is well done) street trees in NYC. HOWEVER, there are many things we can do to help care for the street trees that surround us.
1. WATER! The MillionTrees initative is admirable, however, there are not enough resources to follow up on planting after-care. If you see empty green water bags around a tree this summer, fill them! Regular supplemental watering during dry spells is vital the first 1-2 years after new trees are planted.
2. ALB! - Educate yourself and lookout for Asian Longhorn beetle evidence and call the Parks Dept immediately if you seriously suspect an infestation. It is rare to actually see the beetle but there are telltale evidence left on infected trees. We all have to manage this infestation before it escapes Upstate. ALB is partial to Maple trees, among others. If it does get Upstate, goodbye maple syrup industry, not to mention the Fall foliage! It was discovered in Greenpoint, Brooklyn. As guerilla gardeners, everyone should be aware that fallen branches and other timber should not be moved from its location to help minimize the spread. Leave fallen branches in the area they fell and call 311 for them to deal with.
3. STOP THE SUFFOCATION - tree roots need to breath! It is ok to underplant trees with annuals, bulbs, and shallow rooted perennials. This is my fav way to guerilla garden but it must be done properly (check out Brooklyn Botanic Garden's website for tips). It is NOT ok to create a raised bed and bury the bottom of the trunk with soil. This will slowly contribute to tree decline and eventual death by suffocation. I would love to rip out all the raised beds in Williamsburg/Greenpoint one of these days! There are tons!
4. REMOVE OLD GUIDEWIRES from trees after a year to prevent girdling. I've seen trees choked to death when the wires are left several years. There is a really great (dead) example of this on Leonard St. in Brooklyn. Tree planters are contractually required by the city to remove the wires after a year but many never do.
I recommend checking out websites of the Park's Dept. or Trees New York for more info. Also, read Chris Roddick's book, The Tree Care Primer from BBG. Just awesome.