In article , "madgardener"
wrote:

Good day to you out there....Madgardener here, I was wondering about what
would happily live in a rather HUGE concrete planter my son got me a couple
of years ago that drains slowly (it has a huge hole dead center). I just
found out that the bricko blocks we lined the new fountain/pond/garden/BBQ
with holes up (bricko= cinder blocks) are alkaline, so because of that I
think the Litodoro 'Grace Ward' I found at Lowes is happy as clams in their
alky holes of soil. But I was wondering if the cement planter (this puppy is
HUGE, it originally was outside of a restaurant for ornamental planting
potential on the foyer entrance, if I coulda gotten all four, believe me,
despite the weight, I would have g) could be alkaline as well? It's
deffinately a cement product, and as large as it is (it holds three 40 pound
bags of soil and there are happy wild violets in the soil since I removed
the very dead red dogwood. The dogwood had anthracnose. Among other
things. I need to know if there is a ph problem with this thing, and if I
have to, I will plant sedums and such in it and dolly it to a sunny spot.
Any suggestions once we figure out the ph? I hate to waste such a fine and
large planter.
madgardener in a bit of writers block lately

Alkalinity doesn't leech all that greatly from well-cured concrete. When
laying fresh concrete the ground all around it gets alkalinized. A highly
acidic soil in direct contact with concrete will leech it somewhat, so
something seriously alkaline-hating might be effected (thought shouldn't
include dogwood, depending on species; some, like carnellian cherry
dogwood, even prefer a slightly alkaline soil).

Generally speaking the leeching will be so slight that acidic soil might
move a little closer to neutral which is still basically good soil. Even
the slight alkalinity at the contact-edge should wash through from normal
waterings. The reason some trees can get chloratic next to sidewalks &
foundations MOSTLY is because of the amount of run-off & leaching that
occurred before it was fully cured, or during the concrete-pouring moments
themselves.

Or when concrete is extremely old or poorly made, & really is breaking
down (which can happen from atmospheric & soil contaminants already
harmful to plants & people) its surface gets powdery, it loses strength,
brittles, crumbles, & cracks. At that point it may be doing some seriously
bad alkalinizing of soil. But if lime leaches out of concrete, it loses
strength & toughness; so as long as you can look at that planter & tell it
is an undecaying solid fully cured hunka concrete, it can't hurt any but
the most radically alkaline-intolerant plant such as couldn't even be
grown near a lawn.

If it worried you even so, you could paint the interior with a rubberized
paint or enamalizing paint. The only reason cement leeches even a tiny bit
is because it comes in contact with something acidic (so you can't put
buttermilk in a concrete container without leeching lots of lime). A paint
barrier keeps even the moderate acidity of loamy soil from interacting
with the concrete.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/