Re: Shade garden help

Planting under trees is one of the primary challenges of shade
gardening.  It can be done, but it is not as simple as creating a bed
or border in soil that is not completely infested with tree roots.

Trees send roots out at least 2.5 times the diameter of their crown -
and that's not absolute; could be more or could be less.

Some trees are shallow rooted (maples) and some are deep rooted (most
oaks), but all of them will have some roots within the top foot or so
of soil....these are their feeder roots.  All will also have roots
much deeper, which are usually the roots that help hold them upright.

Trees are sensitive to changes in grade elevation over their roots -
to a more or lesser degree, depending on the tree.  For some trees,
even a minor addition of soil can kill them over a period of some
years and some don't seem to mind much at all.  This also goes for
removing soil from root areas.

Tree roots require air as well as water and when too much soil is
piled on top of the natural grade, it cuts off their air supply and
changes the way water reaches them, which kills the roots and thus
the tree.

That said, I have, for many years, planted under assorted trees by
adding about 6" to 8" of VERY light mix - primarily organic material
with only a little of my native clay.  I do not completely encircle
any one tree and I keep this mix at least a foot or two away from the
tree trunk.  In one bed, where I have a red maple, dogwood and black
locust clump, I have dug out the maple roots on one side several
times and added this light mix.  That maple tree seems to thrive on
this - infiltrating the new mix as fast as it can.

You will need to retain this light mix and be aware that in a year or
so, it will sink considerably, so plant your plants so that their
root balls won't end up high and dry and be prepared to add mix to
the raised area as needed to keep roots covered.  I have used old
logs, wood edging, rocks and whatever I can get my hands on to retain
areas to be planted.

Your goal is to provide an area for the plants you want to plant to
get established before the adjacent tree roots discover all the
goodies and fill the area with their roots - which they will do, esp.
maples.

If you can, try to keep planting areas 4' or more from any tree
trunk.  If you want to plant shrubs, poke around with a digging fork
and see if you can find a pocket between large tree roots so that you
can dig into the native soil as well as adding on top so that your
shrub can have a bit of space for its roots to grow - they will
eventually grow over and under tree roots, adding to the root web
just under the soil.  You may need to remove a few smaller roots from
any of these pockets...this is OK.  Trees can stand a certain amount
of root loss without difficulty...they just grow more of them:-)

You will need to be able to provide supplemental water for just about
anything you plant under trees. In the first place, if you use a
light mix, water will drain fast from your plantings and in the
second, tree roots will get the lion's share of water going.  You can
try to use plants that are tolerant of woodland/tree competition, but
even they will need supplemental water until they are well
established.

If you are working around a dead stump, go ahead and dig out whatever
roots you can find  - they will also be dead or should be if they
belong to the stump.  You can leave them; they will eventually rot
and feed the soil, but if you need to get into the soil there, you
can remove them.  You will find, however, that all roots - living and
dead - will be making a web and be hard to distinguish unless you
trace from the dead stump.

If you feel like you must remove roots, once you get past the first
6" or so of solid root web, you will find much more open soil...it's
that top 6" that's really tough going...you need to use a digging
fork, a shovel or spade will not work.

You can dig individual areas - smallish, like for a shrub - cutting
roots as you go - and not do serious tree damage as long as you don't
completely circle a tree; you will be leaving most of the roots
intact.  If you do this, loosen as much soil as you can with a
digging fork around the planting area without actually prying up
roots so that your shrub roots have looser media to penetrate.  When
you need to cut roots, do it cleanly - don't just rip them off with
jagged tears.

Rototilling under trees with rootweb soil won't work....this is hand
work:-)

Your best bet is to consider your ground and trees and try to locate
shrubs where the tree root web is thinnest - between trees at their
drip lines or farther out - and instead of thinking about planting a
solid area under trees, do several smaller raised areas of major
plants and start some groundcovers in between, which will eventually
tie everything together.

Marge Talt, zone 7 Maryland
mtalt@hort.net
Editor:  Gardening in Shade
-----------------------------------------------
Current Article: Wild, Wonderful Aroids Part 3 - Amorphophallus
http://www.suite101.com/welcome.cfm/shade_gardening
------------------------------------------------
Complete Index of Articles by Category and Date
http://mtalt.hort.net/article-index.html
------------------------------------------------
All Suite101.com garden topics :
http://www.suite101.com/topics.cfm/635

----------
> From: Sophie Rapaport <sophieruth@charter.net>
> 
> I am not sure if it strictly "perennials" topic but I need help
creating the
> shade garden on my new  to me but really very old - the house dates
from the
> early 1800) property. On one side of my yard the light is just
right for the
> shade perennials and shrubs.   The problem is with the soil - it is
so full
> of tree roots that digging it even to the depth of  few inches
proved
> impossible. I tried to plant some crocuses and small daffodils
there and
> could not do it. The roots come both from the trees growing there
now - (old
> hemlocks, maples and oaks) and also from the numerous stumps of the
trees
> removed by the previous owner. Is there any solution short of
removing the
> stumps and rototilling  (?) the soil? Berms? Raised beds? Please
help - any
> suggestions will be appreciated. Sophie Rapaport Zone 5B Central MA

---------------------------------------------------------------------
To sign-off this list, send email to majordomo@hort.net with the
message text UNSUBSCRIBE PERENNIALS
Other Mailing lists | Author Index | Date Index | Subject Index | Thread Index