Fall!
High time to prep poinsettia for bloom, elevate low trees
We have tended two nice-sized poinsettia plants, 30
inches high, since purchase last Christmas. They are in the
original eight-inch pots and were placed outside in a partly shaded
area and watered all through spring and summer. Of course all the
leaves are green but the plants have remained healthy looking with
no loss of leaves.
How can we treat the plants to ensure they produce the
nice red leaves for the holidays? - M.G. -
Keep them in full sun or under grow lights during the day so
they have enough light to remain full and healthy. Check moisture
in the potting mix often and water carefully so it's never sopping
wet or very dry. Most important, for bloom, block out all light for
an unbroken 12 to 13 hours during each 24 hour period.
What you're doing is manipulating the plant's chemistry. When a
leaf is lit, it uses carbon dioxide, water and sun to produce its
own sugars for fuel. There are byproducts such as oxygen from this
photosynthesis. When it's dark the leaf can't produce its own
energy and switches to burning carbohydrates made while there was
light. Chemicals that accumulate while the leaf is burning carbs
are different from photosynthetic byproducts. In "long night"
species like poinsettia, it's only when carb-burning residues in
the leaf reach certain concentrations that flowers begin to
form.
A New Year poinsettia?
By early November, commercial growers have already put their
poinsettia crops on long nights, since flower budding usually comes
two to three months later. If until now your plants have been
lighted at night or if their dark period was disturbed rather than
unbroken, you're late. You may have New Year poinsettia blooms
rather than Christmas decorations.
Even momentary light and dim one- to two footcandle illumination
such as might leak in through doors from adjacent rooms constitutes
disturbing the darkness. As Paul Ecke writes in the commercial
grower guide The Poinsettia Manual, "Each year more
and more growers are having trouble getting poinsettias to properly
set bud in autumn because of extraneous lights shining into the
greenhouse at night."
So be strict about the darkness until you see flower buds
forming. Then you can stop being careful every night. The growth of
those flower buds will prompt the plant to produce its trademark
brightly colored leaves.
Short report:
Every tree and shrub in my landscape was planted too
deep...
I took your Practical Gardening class. Our discussion
about the root flare -- that place where the trunk widens and meets
the roots -- and how it must be planted at ground level, made me
crazy. We bought 60 trees and shrubs this summer. I checked and saw
no root flare on any. So I scraped away all the mulch and topsoil
until I got to what I thought was the root flare. On further
inspection that flare turned out to be burlap wrapped around the
trunks 2 to 3 times! So I have started cutting the burlap off the
top of the root balls. I've completed about 20 plants so far. -
D.R. -
You're doing the right, thing, D.R. Even if burlap, string and
wire cages could rot away quickly enough to allow unimpeded growth
of the roots -- they don't! -- arborist organizations and
university extension services would still recommend that we take
them off once we get the plant into its planting hole. Only then
can we see and correct the planting depth for things like wadded
necks of burlap that look like flares, or too-deep planting by the
grower of bare root plants set out in a field for eventual sale in
ball-and-burlap (B&B).
We're not surprised by as much as 5 inches of extra soil
covering the flare in trees in B&B or large pots. It's one of
the first things we look for and the most common problem we find
when we investigate why newly planted woody ornamentals are
struggling. We work with trowel, spade, scissors and wire cutters
until the flare is visible and at ground level -- even digging up
and resetting plants as necessary. When we replace the mulch we
make it 2 to 3 inches deep but keep a bare area next to the
trunk.
Below, left: When a tree is planted too deep, it will lose
far more root when it's dug from the field, compared to one set at
the right level (below, right)
Hoo boy, do we need Sponsors! The graphic above comes from our
magazine, Janet & Steven give you
Trees, sales of which provide essential operating fees for
GardenAtoZ.com. Yet the magazine also has a great deal of pivotal
information we could dearly use here on the website... if only you
would Sponsor us we can start posting some
of that magazine ahead of time!
Green thumbs up
to using branches pruned from trees and shrubs to make rustic
fences, stakes for floppy perennials, holiday decorations or twig
sculpture right on site. Taxpayer-funded yard waste recycling
facilities are great but the volume of debris we send there keeps
rising as does the cost of fuels required to process it all. Doing
all we can to reuse leaves, branches and clippings where they fall
is better for the environment and our tax bills.
Green thumbs down
to golfers who can't take a joke. Never have we had such quick
and vehement response to a "thumbs down" than from summer evening
golfers supporting Daylight Savings Time. Don't worry guys and
gals, we're not launching any campaigns to rescind DST and ruin
your league play. However, your family gardener truly is on the
short end of the DST stick. How about recognizing that with one day
of your focused help each April and October?
Originally published 11/2/02