All things that will decompose in the soil are organic
Dear Janet & Steven,
Tell me about fertilizers, please! What do you fertilize
with? When? How?
I want to try to use organic gardening methods. Which
fertilizers will do the trick that are organic? - M -
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The ideal time to fertilize is when plants are most actively
growing, such as in spring when houseplants resume growth, as
outdoor plants leaf out for the year or in summer when fruit is
growing rapidly. The trouble is that every plant has its own
timetable. The snowdrops in our garden are forming seed now, yet
the Japanese anemones that occupy that same space aren't even
stirring yet. The cranberrybush viburnum that overhangs and
underlies that whole area won't reach its greatest need for
fertilizer until June and July as it forms a new crop of brightly
Rather than trying to keep up with all these plants
individually, we apply a slow release fertilizer made from poultry
manure to the whole bed in spring or in fall, spreading it on the
surface and then covering it with mulch so it will become available
to the plants a little at a time, whenever the soil is warm enough
that its microorganisms and "soil animals" can digest it. Sometimes
we follow up with a water soluble fertilizer during summer for the
heaviest feeders. Miracle Gro can serve this purpose, or fish
emulsion or seaweed solutions.
Photos at right: What's the common link between all the
plants and plant categories shown here? They're all in active
growth and so nutrients are as critical to them as vitamins to a
growing human child. These new leaves will never match the size,
color, flowering-/fruiting ability and natural pest resistance of
the mature foliage unless the water coming up to it now
has come from soil with an ample supply of nitrogen, phosphorus
and potassium. (Top to bottom: Common houseplant Schefflera
arbicola a.k.a. umbrella plant resuming growth after
the winter stall, American beech leaves (Fagus
grandifolia) expanding in April, perennial daffodils emerging
in spring, and annual seedlings of annual flowers and
Fertilize to correct the soil's lack, not the plant
The ingredients in fertilizer aren't plant food. Plants
all of their own food by creating sugar and starch from sunlight,
water and air. As they grow, the plants incorporate various
minerals from the soil. Fertilizers are mixtures of those
nutrients. They are the equivalent of vitamin supplements for the
soil. The best fertilizer is one that supplies what the soil around
that plant's roots might not have in enough quantity to meet all of
the plant's needs.
Most soils have all of the minerals a plant may need, but to
grow to its full potential a particular plant may need elements in
different proportions than what that soil will provide. A soil test
will tell you what to add for your soil to produce a good crop of
lawn, flowers, shrubs, Christmas trees, etc.
The soil in our yard tests fine for most elements but is a
little low for potassium, so soil test results recommended adding
relatively more potassium than other elements. If
we didn't have the test, we would apply a fertilizer with equal
amounts of nitrogen, phosphorus and potassium, such as a 10-10-10
granular that has ten percent of each of those major nutrients, or
a 2-2-2 dried cow manure. All of these are called "complete,
balanced" fertilizers for their
1-1-1 ratio of major nutrients.
Since we do know our soil's deficient in potassium we use a
balanced fertilizer plus some greensand, which is six percent
potassium, 0-0-6. Alternatively we could use the balanced
fertilizer plus muriate of potash which is 60 percent potassium,
Organic in fertilizers means carbon and less processing
Organic growers use raw materials as fertilizers rather than
granulated processed chemicals. To grow organically and add
potassium, use the greensand rather than muriate of potash, since
greensand is a simple rock powder but the other has been treated
with chemicals to make more of its potassium water soluble.
What counts as an organic slow release fertilizer? Manure,
cottonseed meal, coffee grounds, decaying leaves, bark mulch and
anything else that will decompose within the soil. They don't
"melt" into water like processsed, salt-based fertilizers but
release their constituent chemicals gradually as bacteria, fungi,
insects and worms digest them.
These organic materials also add carbon, which becomes humus and
beefs up the structure of the soil. That increases the soil's
ability to hold water and nutrients.
You can rely on compost or leaves for fertilizer but these are
relatively low in nutrients so you must use them in large
quantities and encourage their decomposition. Also, you won't know
for sure how much of the essential elements you're adding. To
supplement a specific soil , buy packaged organic products that
have been tested for nutrient content and labeled as fertilizers.
These are available at many garden centers. You can also look for
retailers that specialize in organic additives. (Do these all have
quaint names, like our local Chelsea Farm Co-op or Uncle Luke's
Feed Store? Maybe!)
Finding shrubs were mashed under snow
Don't try to bend or tie branches into place now. Prune off
what's broken, water well and wait for the plants to leaf out. Then
prop the branches -- by stages if necessary -- into better
positions if they don't rebound on their own as the sap rises. As
this year's leaves mature, new wood will form in the branches.
That's when they need to be in your desired alignment.
Why not suggest peat pellets in Styrofoam
... for that person who wasn't much of a gardener but wanted to
start seeds with young children? Asks S.B., who also points
out, "Those peat pellets are found everywhere. They are
cheap and easy to start seeds with no mess for the novice as well
as weekend gardeners." Good idea, S.B.
Green thumbs up
to all the rabbit pellets on our lawns and gardens. That's
organic fertilizer of the
Right: See the droppings on the ground below the badly
chewed canes of dwarf burning bush (Euonymus alatus
That's rabbit dung!
Green thumbs down
to all the damage those hungry rabbits did to shrubs and trees.
It's an expensive way to fertilize!
Originally published 3/20/04; updates 4/2/14
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