CO-Horts Blog

Thursday, May 12, 2016

Sins of the Landscape

My fellow Horticulture Agents will agree; sometimes it is hard to drive around town and see the landscape “sins” that are going on.  One of our Tri River Area Master Gardeners recently wrote an article on trees.  It pained her to see them improperly planted, pruned or ignored.  Please do your homework.  Plant the right tree in the right place.
Plant using the latest updated planting techniques.
Do your homework before you prune.
If the tree is in the right place, you should have minimal pruning to do.  Always remove dead, dying and disease wood as soon as you see it.  And please never, never top a tree.  Some people will say they are pollarding.  Pollarding is started on saplings and was used in Europe to produce a quick large amount of wood that was then used for firewood.  “Pollarding”, aka topping, should never be done on large trees.  When topping is done, it is committing the tree to a short life.  Talk to your local Masters Gardeners about trees.  They will be happy to fill you in so you can grow trees that live longer than we do.  Leave a Legacy.
Right plant, right place

Now on to the next “sin” I witnessed driving home the other night.  A local business was laying weed fabric.  Well, the big problem with this is they were laying it over already existing fabric and decomposed granite rock.  Then they were putting a 1” or larger river rock on top.  I assume they were doing this to help conquer the weeds.  The problem, actually there is more than one, is first: old fabric gets dirt built up on it and it essentially clogs the pores of the fabric.  This dirt build up on top is why the weeds are now there.  Secondly, one has to understand the movement of water through different materials.  Water moves through one material before it will start to penetrate another layer.  These layers are called interfaces.  So by the time water moves through 4 layers of material how much is going to actually get to the soil below and to the roots of the plant.  The correct thing to do would be to remove the existing rock mulch and fabric and start over.  Or not use fabric to start with and use other methods to control weeds.

Dandelion photo by Susan Carter

Controlling weeds starts by identifying the weeds that you are trying to get rid of. We have winter annual weeds that start growing in late summer or early fall.  These them start growing like mad in early spring and are already setting seed at lower elevations.  Downey Brome, aka Cheatgrass, is one great example of a winter annual.  Then we have annuals that germinate in spring or summer.  Biennials type of weeds grow vegetation one year and bloom and go to seed the second year.  And perennial weeds are ones that will come up at least 2 years or more from the root system.  Woody weeds fit in this category.  Pre-emergents can be used to control weeds in areas like the rock mulch bed in my story, but it is important to know the identity of the weed or its life cycle so you apply the herbicide at the appropriate time.  Of course, manual removal of the weeds is one way to control them.  Spraying herbicide on them after they have germinated is another and trying to out compete them with properly grown turfgrass or cover crops is another. (Always read the label and follow instructions on pesticide labels.)
Feel free to take weed samples to your local Extension office.  Please bring the entire plant and if it is blooming, that is even better.  The more information we have, the better we can help you.  So do your homework, choose what works best for you and your landscape, to help you maintain a healthy landscape.   Blog posted by Susan L Carter, Horticulture Agent, CSU Extension Tri River Area

1 comment:

  1. Thank you for the note about weed barrier. I have found the only thing that grows well in weed barrier are weeds. Desirable plants will send roots out on top of the weed barrier in the decomposing bark mulch. This effects the cold hardiness of the roots as well as the drought tolerance of the plant. Unfortunately everyone uses weed barrier and many municipalities require it! JUST SAY NO TO WEED BARRIER!