Hi Gardeners
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| Tulip slyvestris |
Since I wrote last the ground was covered in about 8 inches of
snow. A little has melted, although it’s
not that warm. The trees are coming out
of dormancy and they are producing enough heat that snow is melting around
their bases leaving spots of bare ground.
That’s probably what keeps the robin that’s singing each morning going.
But the flowers are buried.
When I walk to the barn each morning- or rather wade- since I am
not shoveling anymore- I hear the birds singing like crazy. It’s 7 days until calendar spring and I hope
the weather will improve to match it. Our weather is not as bad as some of you
have on the northeast coast and in a few other places. I try to be thankful for that. If you are one of the snow buried I feel for
you. It’s snowing pretty good as I write
this, but the next few days are supposed to be snow free and milder.
Don’t worry about flowers that came up and got snow buried. Unless they were just about to open their blooms,
they will be fine. Even if the blooms got
damaged the plants should survive. Snow will actually insulate the plants. Most
perennials that may have started growing will just suffer some cold damaged foliage
and won’t be permanently injured.
If you had branches cracked or broken by heavy snow and winds, make
sure to trim them off evenly close to the branch collar. You do not need pruning paint. If evergreens and shrubs were bent and bowed
by snow let it melt to see if they spring back into shape. If they don’t you may have to gently tie them
together or stake them temporarily. Be
very careful you don’t crack branches moving them, it would be better to leave
them if that’s likely. Remove ties and
stakes in a few weeks.
If you are anxious to see some spring blooms you can cut and force
some early flowering plants to bloom inside.
Pussy willows, forsythia, fruit trees, flowering quince, and redbuds
that have big flower buds can have branches cut and placed in a vase of water
inside. They should bloom quickly this
time of year.
Have you fertilized your houseplants yet? It’s time to start, especially if you have
patio type plants you want in bloom when the weather warms up.
Let’s all hope for better weather next week.
Why does soil (or potting medium) disappear
from flower pots?
Have you ever looked at a pot and realized that the plant had sunk
into it by several inches, as if something had removed planting medium from the
bottom? Most people who raise plants in
containers, whether as houseplants or in outdoor planters have experienced
this. So where does the potting medium
go?
Well it doesn’t get absorbed or “used up” by the plant, which is
something many people think. Plant roots
don’t absorb potting medium or soil. In
some cases, some potting medium may wash out through the drainage holes, this
is more likely if the pot is outside and subjected to heavy rains. However, the correct answer most of the time
is that the organic matter in the pot has decomposed, broken down, into smaller
particles.
Potting medium generally doesn’t contain any real soil, it’s a
mixture of organic and man-made ingredients like ground bark, coir, peat,
vermiculite and perlite. Even inside the
home the organic ingredients begin to be broken down by microorganisms and over
time they are reduced to smaller and smaller particles. These particles settle, and some may even
dissolve in water. Even if you filled
your pots with garden soil the organic matter in the soil will eventually break
down.
Think of the process as a mini- compost pile. You start with a huge pile of leaves, weeds,
manure and other things but when the pile is ready to be used it has been
greatly reduced in volume. Or think of
filling a pot with coarse chunks of wood chips.
Then take those wood chips and run them through a grinder until they are
the consistency of potting medium. Now
they won’t fill the pot even though they filled it earlier. The potting medium
you fill your pots with has small particles of organic materials, but they
break down into even smaller particles over time.
If the plant is vigorously growing and has filled the pot with
roots the break down of the potting medium may not be obvious. What will be obvious though is that when you
water the pot, water seems to flow right through it and the plant needs
watering frequently to keep it alive.
That’s because there is very little organic medium left to absorb water. Water is held in the pores of the potting
medium and the smaller the particles of organic matter, the smaller the spaces
or pores between them.
So, what do you do when you gaze into a pot and discover it has
half the volume it once had? You can
simply slide the plant the plant out of the pot and add some fresh potting
medium to the bottom. You may have to
fill in some along the sides also. You
want the top of the original root ball to sit about an inch below the pot rim. Don’t add soil to the top of the pot. You don’t want the stems of the plants any
deeper in the potting medium than they were before.
If the pot does seem to be losing potting medium or soil through
the drainage holes, because you can see where it has washed out, slide the
plant rootball out of the pot and add a paper coffee filter or a piece of screen
to the bottom. Then add some new potting
medium as described above.
If the pot still seems full but is having trouble absorbing water,
you can re-pot it in a slightly larger pot with fresh potting medium. Roots that circled around and formed a thick
mass at the bottom of the pot can be trimmed straight across an inch or so from
the bottom of the root ball and the roots teased apart slightly. If the plant has multiple crowns or there are
several plants in the pot you may want to divide the plants and make a few
smaller pots.
Sometimes pots that seem to be shedding water instead of absorbing
it are simply over dry and the medium has shrunk away from the sides of the
pot, leaving an easy channel for water to flow through. Try soaking the pot in a bucket of water for
an hour or two, the water should come to just over the top of the pot. It may float if its very dry, hold it down in
the water and let air bubbles escape until it settles into the water. Take it out after the potting medium is
thoroughly soaked and don’t let it get that dry again.
When you have large planters or raised beds outside, adding
organic matter to the top of the bed when plants aren’t in it can correct the
problem. You can dig it into the top layer of soil or potting medium or just
let it decompose on top. Don’t add a lot
of new organic matter or potting medium to the top of planters while plants are
growing in them. Very large planters can
be difficult to slide plants out of to add potting medium to the bottom. You may
have to take the plants out and add new potting medium to the top, and then re-plant
the plants.
Potting medium that has broken down to very fine particles doesn’t
hold water well and may be more prone to crusting or hardening. You may want to
discard it and use new potting medium. Because plant roots usually need the
depth of the pot for good growth and potting medium is needed to balance the
weight of the plant top growth, correct shrinking soil medium as soon as you
notice it.
More
seed starting tips
These tips are more “garden-granny” type than last weeks
tips.
Every inside seed starter should have these tools in
their “kit”, a pair of tweezers, a small pair of scissors, a nail file or nail
clipper, a spoon or spork- plastic is fine, a pencil with an eraser, a small
ruler, a marking pen.
The tweezers will help thin or transplant seedlings. The scissors will cut out seedlings you need
to thin out and are useful for other things.
The nail file or clippers are for nicking hard seeds so water can enter
and begin the germination process. I
like to use a nail clipper to pinch out a piece of seed shell on one end of the
seed. Don’t nick the curved side of the seed, the side with the scar. This is where the plant embryo will be.
A spoon works well as a tiny spade for transplanting
seedlings. A spork, one of those
spoon/fork combo’s works really well when transplanting. If you moisten the
pencils eraser you can pick up small seeds that fingers have difficulty
handling and place them where you want them.
With really fine seeds a moistened toothpick may also work. The ruler
let’s you actually measure how far apart seeds are and the marker lets you
label what you planted- because you will forget.
If you are trying to transplant and not thin, always move
the plant by it’s leaves, not the stem.
If you break a leaf it’s fine, one will grow back. If you damage the stem you’ve probably killed
the seedling.
Save these things to make plant labels: popsicle/craft
sticks (wash used ones with hot soapy water) plastic window blinds (cut the
blind slats in pieces with scissors) plastic table wear- the handles can be
written on or the knife blade or spoon bowl, and paint stirring sticks.
Save these things to start seeds in; deli containers with
clear dome lids, cake and baking pans with clear lids, cheap aluminum roasting
pans (for trays and mixing potting medium), Styrofoam cups. Wash all used things with hot water and soap
before using for seeds.
Do you have trouble spacing seeds because they are hard
to see against the starting medium or soil?
Get a bag of white sand or parakeet gravel. Make your furrow, put a little sand or
parakeet gravel on the bottom and place your seeds. Cover with starting medium. Do not use flour or other food items. They will mold and attract animals.
Outside when planting seeds and you need to mark where
different varieties start or where your planted rows are, you can use the sand
or gravel in a thin line or even a little sawdust or wood shavings to mark or
outline areas. You can also mark rows
with sturdy sticks that you have dipped or sprayed with colorful paint.
If you have trouble stooping to evenly space seeds use a
piece of PVC pipe cut to just the right height for you. Place one end where you want the seed to go
and drop the seed in the other end while you are standing- or sitting.
A bag of cheap wood skewers can make supports for small
plants. If you place them pointed sides
up and circle your seedlings they can protect them. Plastic forks with the tines up can also
protect seedlings.
Save cardboard toilet paper/paper towel tubes and cut
them in sections. Use the sections
around seedling plants outside to protect plants from cutworms. You can also set these sections in a tray,
fill them with seed starting medium and use them to start seeds like peat
pots. I do this and find it works well,
the cardboard peels off easily when you transplant the seedlings.
Should
you grow castor beans?
The castor bean plant (Ricinus communis) makes a commanding and exotic statement in the
garden. Gardeners are often attracted to
a stately, gorgeously colored plant and want one of their own, until they are
told how poisonous the plant is. So,
let’s address this issue first- how dangerous is the castor bean plant? The answer is- pretty dangerous, but that
doesn’t mean you can’t grow it.
Many common garden plants are poisonous, many gardeners
have no idea how many potentially deadly plants they have in the garden. Here’s
an article that will help you determine what poisonous plants you have.
Castor beans, however, are the source of ricin, one of
the world’s deadliest poisons. Ricin is
a chemical weapon used by many country’s and has been used to commit murder or
suicide through the centuries. All parts
of the castor bean plant are at least mildly poisonous, but ricin comes from
the plant’s seeds. The beans are also
the source of castor oil, a potent laxative that’s also used as an engine
lubricant, in brake fluid, as biofuel and in cosmetics.
Castor bean seeds have a thick, hard coating and if
someone swallows them whole they usually pass through the digestive system
intact, without causing major problems.
However, if the seeds are chewed or ground up, serious illness and death
can result. The poison ricin uses
isolated, concentrated chemicals from the seed and may be made into a gas,
powder, or liquid injectable, which is extremely dangerous.
The suggested fatal dose of chewed whole castor beans is
8 beans for adults and 2 for children. (Concentrated ricin can kill with just a
few small table salt sized grains) There is no current safe antidote for ricin
poisoning, but fatalities rarely occur now from ingestion of beans because of
modern medical treatments such as stomach pumping, intravenous fluids,
respiratory support, seizure medications and other supportive care. But while
it may not kill you poisoning from bean ingestion may leave people with organ
or brain damage.
Castor plants produce their seeds in the fall. Seed
production can be abundant in the right weather. The seeds are very attractive,
although they remind some people of an engorged tick and that’s where part of
their scientific name comes from. They
are bean sized, black, brown or burgundy, with white or dark markings. They have been used as jewelry, but this
would inadvisable around children and pets.
So, the decision a gardener needs to make before planting
this tropical looking beauty is whether they have children, pets, livestock, or
vulnerable adults who might ingest seeds if they came upon them and if so, are
they willing to risk planting castor beans?
If tight security is maintained on the seeds before planting and flowers
are trimmed off before they make seeds the danger is greatly lessened. Pets and
livestock shouldn’t be able to eat the plant foliage either. Gardeners should know however, that some
people also have a serious allergic reaction to handling the plants or seeds.
If you think growing castor beans is fairly safe in your
situation then read on about the plant and it’s growing needs.
Growing
castor beans
Castor bean plants are tender perennials, native to
Eastern Africa but naturalized in many tropical areas around the world. In the US they are usually grown as annual
plants. In the wild plants form small
trees 30 feet high or more. In the
garden plants may reach 10 feet high in good conditions, so they are best as
specimen plants or back of the border.
Castor bean plants have leaves arranged alternately on
the stem, on long petioles. The leaves
are palmately compound, (shaped like a hand) with 5 -11 lobes. Leaf edges are serrated and there’s a prominent
mid vein running through each leaf segment.
Some cultivars have narrower leaf segments than the species. The species
has green glossy leaves but cultivars (varieties), have been developed with
burgundy, purple and variegated foliage.
Leaves can be up to 2 feet long.
The flowers of castor bean appear in late summer on the
top of the plant in clusters. Male and
female flowers are separated and neither have petals. The male flower is a simple cluster of creamy
white or yellow stamens, that produce abundant pollen that is carried away by
the wind. It may be allergenic to some
people. The female flower is an unusual
and attractive red globe structure, with three segments and feathery
appendages.
Fertilized female flowers turn into bristly 3 segmented
globes the size of a golf ball. Each pod
segment will contain one seed. When
immature the seed pods are green in the species and red, pink or purple in the
various cultivars. This is the stage at
which people may want to remove the seed pods and safely dispose of them. Even
immature seeds are poisonous.
As pods ripen they
start to turn brown. When they split
they propel the seed some distance from the plant. In warmer zones the plants may become
invasive if seed pods aren’t removed before they mature. Castor bean seeds are glossy, in a variety of
colors with interesting swirls and streaks of either white or dark colors. Each seed has a spongy appendage at one end
that helps the seed absorb water from the soil for germination. If you save seeds remember they are very
poisonous and store them safely out of the reach of children and pets.
Gardeners can start castor bean plants from seeds or buy
plants from some nurseries. Castor beans prefer full sun in moist but well
drained soil. They should not be planted
outside until all danger of frost has passed.
In zones 8 and higher castor bean seeds can be planted
directly in the ground. In lower
planting zones start castor bean seeds indoors 8-12 weeks before your last
expected frost. Castor bean seeds
germinate better if nicked and then soaked in warm water overnight before
planting. Remember- seeds are poisonous.
‘Impala’ is a castor bean variety that is shorter
and more compact, about 4 feet tall. The
‘Carmencita’ series has leaves and flowers in a variety of colors. ‘New Zealand
purple’ has narrower leaves in purple shades.
Other cultivars are available.
In the garden castor bean plants grow rapidly in warm
weather. Keep them watered in dry weather. Because they kill insects which feed on them
insects aren’t a problem. Deer and
rabbits don’t eat them either. There are
few diseases that bother them. While
moles won’t eat the plants (they don’t eat plants anyway) the idea that
planting the castor bean plant around the yard to repel moles is simply an old wives’ tale. It doesn’t work.
Castor
oil
When castor beans are pressed they produce an oil. The oil has very little ricin in it and
modern castor oil is also treated with heat to remove any remaining ricin. However, no one can say the oil is harmless,
as anyone who has been given the oil can testify. Castor oil is a very efficient laxative that
causes strong stomach cramps and explosive diarrhea. It was used as a tool for torture in earlier
times, with people being forced to drink the nasty tasting stuff in large
quantity. Then they were placed in
public stocks to be thoroughly humiliated as they faced excruciating cramps and
then the inevitable embarrassment of massively soiling themselves. Some even died, not from embarrassment but
from dehydration.
Castor oil is sometimes still prescribed to clean out the
bowels before medical tests. People
still buy it as an over the counter laxative, and I’m sure some parents still
use it to punish children. Pregnant
women near term use it to try and start labor.
(Pregnant women who don’t want labor to begin should not use the stuff,
it’s also listed as an abortifacient).
The oil is also used in a variety of industrial
lubricants and was once used as lamp oil.
It’s used in plastics, paints and varnishes. And some people even use the stuff in cosmetics
and various herbal concoctions. The
“cake” left over from pressing seeds is heat treated to remove any remaining
ricin and then used as fertilizer and an additive to animal feed.
I don’t recommend experimenting with castor beans, either
the seed or the plant. Ricin is water
soluble. It is not
safe to make tea with the seeds or foliage, nor to cook and eat the beans,
no matter how they are prepared and no matter what you read on social
media. Herbal preparations with castor
bean in them should be avoided.
If reasonable precautions are taken there is no reason
why most gardeners shouldn’t grow castor beans for their tropical beauty.
Shamrock
tales
Ah, the
legends of St. Patrick’s Day. (March 17).
Many legends abound about the man and the day. Nobody really knows if St. Patrick used a
clover or shamrock to teach about the holy trinity or whether he used shamrocks
to drive out snakes or whether he even wore shamrocks on his blue, (yes blue)
monks robes as is so often depicted in pictures. But somehow the shamrock got associated with
him and with Ireland in general. But
what exactly is the shamrock?
Here’s
how we determined what a true shamrock is. In the late 1800’s a debate raged
among botanists in Europe and America over this very important question. Some believed firmly that shamrocks were wood
sorrel or Oxalis and others that they
were of the clover or Trifolium
family. Both plants grow well in
Ireland.
A
clever botanist by the name of Nathaniel Colgan carried out a survey in 1893 by
asking residents of Ireland to send him pressed samples of the plant they
considered a shamrock. The survey found
that the Irish overwhelmingly chose a clover, either Trifolium dubium (Lesser or Hops clover) or Trifolium repens (White Clover) although a few wood sorrel leaves
arrived also.
Side
note: The “lucky” clover leaf with 4 leaflets instead of 3 is a rather common
mutation in clovers and it can be inherited.
In fact, there are varieties of white clover that have been developed
that will have a high proportion of leaves with 4 or more leaflets. These are
grown to make those lucky charms with a real 4 leafed clover inside. There is a
purple leaved variety, T. repens
'Purpurascens Quadrifolium' and a green-leaved variety called T. repens 'Quadrifolium'.
But for
most people the shamrock they are going to see around St. Patrick’s Day is
usually an oxalis. Oxalis are small plants, with a bulbous root. The leaves have 3-4 leaflets, sometimes heart
shaped. Most oxalis have small, 5 petal
flowers that open flat in the spring, although some species have funnel shaped
flowers. Oxalis or wood sorrel species
are common throughout most of the world. There are also a few types of oxalis
that can be planted outside. When
looking for oxalis to plant look in bulb catalogs. They may be called wood sorrel, a common
name. The bulbs are quite inexpensive
for most species.
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| Native wood sorrel |
An
oxalis that was a fad just a year or two ago is the Candy cane oxalis, Oxalis versicolor. It has those funnel shaped flowers, striped
in red and white. The pictures in
catalogs make the plant look impressive, but actually the plants and flowers
are very small. They are hardy from
zones 7-9. It will grow in sun or
partial shade and is best seen in a rock garden setting or in a pot. It should be planted in the fall.
Oca (Oxalis tuberosa) is a South American
oxalis that has an edible root somewhat like a small potato and is used in the
same way. Many oxalis plants have leaves
that are eaten in various parts of the world.
The plants are referred to as sour grass in many areas. The sourness comes from oxalic acid, which if
you ate it in quantity might harm you but small amounts are safe. It was used by sailors to prevent scurvy.
Usually
oxalis sold around St Patrick’s Day have purple foliage with pink flowers and
are Oxalis regnelli cultivars. ‘Iron
Cross’ (Oxalis tetraphylla) is a four-
leaved oxalis, green with purple cross markings and pink flowers. It’s a good
potted plant. Oxalis vulcanicola- ‘Molten Lava’ has orange foliage with yellow
flowers. Oxalis adenophylla ‘Silver Shamrock’ has silver gray foliage with
light pink flowers. It’s said to be
hardy to zone 6. Oxalis depressa is a good pot plant with 4 leaved foliage and pink
flowers with a yellow throat. It’s hardy in zones 5-8. There are other
varieties for plant collectors too.
The
species used as “shamrocks” are usually tender perennials and won’t survive
outside in a cold winter. Keep them in a
bright window and keep them moist but not over watered to the soggy point. A light fertilization once a month with a fertilizer
for flowering plants will keep oxalis blooming for long periods of time,
although they will take occasional breaks from blooming. Well cared for plants will become larger and
live for several years. The tender Oxalis can make great container plants outside
during the frost-free months.
When
temperatures get very hot in the summer, oxalis goes into dormancy and the
leaves dry and fall. People sometimes
think the oxalis has died when it goes into dormancy. Let the pot dry out a
little and store it until fall brings cooler temperatures. Water well, give it a little fertilizer and
soon it will be blooming again. We had
an oxalis plant in the Extension office that did not go into dormancy for at
least two years, maybe because of the air conditioning.
Free
Master Gardener Lesson: soil science part 1
When people signed up for the Master Gardener classes I
used to teach they often expressed concern over the first two chapters that are
covered; plant science and soil science.
They either thought they would be too complex to learn much about or too
boring. Well soil science can be as
complex as you like, what I’ll write about here is just an overview. But soil science shouldn’t be boring because
it’s vitally important to the gardener and the plants he or she grows.
Beneath our feet is a whole, complex world that we are
just beginning to study. Its teeming
with microorganisms all going about their lives and we haven’t identified a
huge percentage of them nor do we know what all of them do or how they function
in the soil biome. Soil is the environment these important microorganisms exist
in so we need to study what it is and learn how plants are our connection to
this other world.
I hear people mocking other people who use the term soil
instead of dirt and consider it a sign of garden snobbery. But there is a difference between the two and
you should learn it. Dirt is something
you don’t want, something useless you sweep up and dispose of, something you
don’t want to touch. Soil is something
wonderful, that gardeners love to get their hands into, something that’s of
great value. But here’s a more
scientific definition of soil:
Soil
is a mixture of broken down parent material- or rocks, called mineral solids,
organic solids that were once living things, microorganisms, and pore spaces
filled with water or air.
Soil does more than nurture and anchor plants, it absorbs
and filters water, is a sink or “sponge” for carbon dioxide and it provides the
base on which we build our homes and roads.
What minerals a particular area of soil holds depends on
the parent rocks that produced it and chemical actions that have taken place in
the soil over millions of years. Rock is broken up by weathering, freezing and
thawing, grinding from glaciers, pounding waves and wind, and activities of
plant roots and animals. It is turned
into soil by mixing with organic materials, further chemical reactions and the
activities of microorganisms.
Every area has different soils, varying in texture size
and mineral content as well as acidity.
Soil also organizes into layers, called horizons, as most gardeners have
seen when they dug a hole. The layers vary in thickness and composition. The
most organic matter is found in the upper layers of soil and soil with more
organic matter is the most nurturing for plants. This is often called topsoil, although that’s
an imprecise name.
Geologists group soils with similar mineral and
structural characteristics and name them. I won’t go into that type of
classification here, but I will discuss some other terms and classifications of
soil that gardeners are likely to run across.
Soil
texture
Soil is made of different size particles. The smallest particles are called sand.
Medium sized particles are called silt and the largest particles are called
clay. When someone talks about having clay soil it usually means that their
soil has a high percentage of large soil particles. Usually soil is a mixture of particle sizes
but soil ranges from almost pure clay to almost pure silt or sand. A soil that has almost equal amounts of silt,
clay and sand particles is called loam.
A soil testing lab can tell you what percentage of soil
particles your soil has (as well as the percentage of major mineral nutrients).
Gardeners should always have at least one soil test done as a baseline and then
you will know your soil texture. Handling
your soil can also give you an idea of what type of soil you have. Soils with a lot of clay feel smooth and if
wet will make a firm ball when squeezed.
Soils with a lot of sand particles feel gritty and even when wet fall
apart easily after a squeeze.
Gardeners can also do the jar test, take a trowel and dig
down about 8 inches and place the whole scoop of soil in a large jar. Add enough water to cover the soil and shake
it up well. Let the jar sit undisturbed
for 24 hours and the soil should settle into layers. You’ll get a rough idea of the percentage of
sand, silt and clay your soil has. The
organic matter should settle at the top and the rest will be your mineral soil
layers.
Soils are usually classified by the percentage of
particle size using a soil triangle. For
example, you can have sandy loam, silty loam, clay loam, silty clay, sandy clay
loam and so on. See the USDA soil
triangle diagram below.
Knowing the texture of your soil is helpful in many ways. Different plant species evolved to grow
better in different textures of soil.
The soil texture helps determine how you manage your garden. Some soils hold water longer, warm up faster,
hold nutrients differently and compact more easily than other soils.
Soil
Structure
Besides texture, different soils have different
structures. Microorganisms in soil
produce a type of gummy material that sticks the various kinds of soil
particles together. This is called an
aggregate. Aggregates have larger pore spaces between them to hold air and
water and those pore spaces act a bit differently than the pore spaces between
soil particles. What is ideal is a soil
structure that looks like crumbly granola.
Because microorganisms are more active in the upper layers of soil where
organic matter is being broken down the soil structure is different there than
deeper in the ground in what is called the sub soil.
Changing the soil structure can help overcome problems a
gardener may have because of the soil texture they have. Soils can drain better or hold more water and
nutrients or provide a better environment for plant roots if the soil structure
is changed. Adding more organic matter
is one of the best ways to improve soil structure. It may take a few years but even the sandiest
or heaviest clay soil can be improved with organic matter. The best way to do this is to simply place
the organic matter on top of the soil and let nature incorporate it.
Some of the best ways to destroy soil structure and make
the soil less hospitable for plant growth are compaction or excessive tilling. Compaction is caused by foot or machine
pressure over time. It breaks up soil
aggregates and/or squeezes them together, leading to fewer pore spaces for
water and air and bad conditions for plant roots.
It’s not so much damage to the grass plant blade that
makes a frequently used path bare but compaction of the soil that keeps its
roots from penetrating the soil and using soil nutrients. When a new house is being built the builders
may avoid hitting or cutting trees, but the machinery needed for construction
may compact the soil so badly that trees decline and die over the next couple
of years.
Soils with more clay are more prone to problems from
compaction, but all soil can be affected.
When the soil is wet it’s more prone to compaction so stay out of your
garden in the spring until it has dried out a bit. It’s also not a good idea to use a heavy
roller to iron out irregularities from mole hills in the spring, especially if
you have clay-based soil and its wet.
Excessive tilling of the soil is also a problem because
it breaks up those soil aggregates and it also re-arranges the soil
microorganisms, which all have their preferred level to exist at. Every time you disturb the microorganisms it
slows the beneficial work they do. You do not want soil as fine as flour, as
some people think. This will crust on
the surface and impede water and air flow. The pores between aggregates
disappear and so does the water and air holding capacity of the soil. Tillers
also tend to compact the soil just below the blade depth, which also impedes
water movement and roots.
Many farmers have moved to no – till management of their
fields and gardeners should follow their lead.
You do not need to till the garden each year and never more than once in
a season. Soil is healthier if tilling is avoided.
Soil
structure can be changed but soil texture can’t be changed. As mentioned above there are
ways to change soil structure. But you
cannot change the texture of soil in any meaningful way by adding sand to clay
for example. It sounds like it would work, but in practice it doesn’t. When you
add sand to clay the clay particles fill the pores in the sand, creating a
really dense soil-like concrete. Nature
can mix soil particles over millions of years by chemical actions and soil
microorganisms but in the short term of garden time spans it isn’t practical
nor effective. If you are unhappy with
the soil, try adding organic matter to change its structure.
Soil
organic matter
Organic matter in soil is found in two forms. Any once
living thing laying on the soil or in the top layer of soil is just called
organic matter. It’s in the active stage
of being decomposed or broken down by soil organisms. Once organic matter has
finished decaying and is a fairly stable product it is called humus. Humus
slowly releases nitrogen, absorbs nutrients and water and keeps them available
to plant roots and increases tilth, or soil structure.
Five to ten percent organic matter is a goal to strive
for when improving your soil. Ideal soil composition for most plants is said to
be 5-10% organic matter, 40-45% mineral soil, 25% water and 25% air. (Note: a few plant species actually do better
in soils with less organic matter.) Organic matter and humus do disappear in
time and should be constantly renewed.
A soil is called organic soil when it’s at least 20%
organic matter and those soils are usually “bottomlands”, once under water and
formed from peat and other plants decaying and mixing with silt washed off
surrounding land. They may be called peat or muck soil also. Often these soils
are also acidic. Some plant species will
grow well in them, but others will not.
The organic matter in soil and the minerals that came
from the rocks broken down in the soil determine the soil pH and the nutrients
available for plant growth. They also determine the color of soil. Soil color varies from light brown to reddish
to almost black.
Top soil is the layer of soil closest to the surface and
that soil generally has more organic matter or humus, therefore it looks
darker. Soil isn’t “better” because it
is dark in color, nutrient rich soils can be light in color. But it probably does have more organic matter
and better soil structure. (Be careful
if you buy topsoil, it is generally collected from building sites or waste
areas and can be filled with debris, weed seeds, and even dangerous chemicals.) Darker soil does have the advantage of
heating up faster in the spring especially if it’s well drained, because darker
colors absorb the sun’s light and heat.
Soil
water and air
As discussed above there are two types of pores in
soil. Smaller pores exist between the
mineral soil particles and larger pores exist between soil aggregates. The
smaller pores hold on to water and nutrients and the larger pores allow for
drainage and air spaces, plant roots need air as well as water. A soil is called saturated when all the large
pores are filled with water and plants vary as to how long they can remain in saturated
soil before their roots are killed.
The smaller pores usually have a film of water clinging
to them and these resist water being
pulled away by gravity and remain available for plants for a longer time. Since clay has the smallest pores it holds
more water. The larger aggregate pores act like a house drain and water moves
through them down deep into the soil, leaving empty spaces to be filled with
air.
Organic matter absorbs water also and slowly releases
it. Water is moved from the small pores and
organic matter by capillary action- water moving from a wet area to a dry area,
plant roots absorbing water and evaporation at the surface.
Since plants need water, nutrients and air in the soil
you can see why both soil texture and soil structure are important. The mineral soil pores hold the water and
nutrients plants need, the aggregate pores drain away excess water and hold
air.
Soil
organisms
Healthy soil teems with unseen life as well as creatures
obvious to the eye. They aren’t structural components of soil but should be
considered to be part of it. Bacteria in
soil are extremely important, they decompose organic matter and perform other
chemical feats that make nutrients available to plants. An ounce of soil can
contain over 30 billion bacterial organisms, both helpful and harmful.
The study of soil bacteria is fairly new, but researchers
are now collecting soils from all over the world and trying to identify the
bacteria in them and what they do. Some
are even being considered for human medicines. Some plant species need an
association with certain soil bacteria to do well. Legume seeds like beans are sometimes
inoculated with soil bacteria to get them off to a good start.
Not all bacteria in the soil are good guys though. Some cause plant disease and even human
diseases. Tetanus is a serious, sometimes fatal human disease caused by soil
bacteria. Gardeners should keep their
tetanus vaccinations up to date since they work with soil.
Fungi are also found in soil. They are considered to be multi-celled plants
but they don’t produce their own food, they break down other organic matter for
food or sometimes live off plant sap.
They are important decomposers of organic matter in soil but some fungi
also cause plant and animal disease.
Mycorrhizae are specialized fungi that interact with
plant roots in a beneficial or symbiotic arrangement. Plants provide food for them, but they send
out a network of tiny filaments that are able to squeeze into soil pores to
absorb water and minerals to pass to the plants roots. About half of plant species in the world form
mycorrhizae relationships.
Mycorrhizae are another organism that are being studied
in great detail. It is thought by some
researchers that plants may communicate through a network of mycorrhizae and
can share nutrients and water to other related plants through them. This has not been conclusively proven.
There’s no evidence that supports buying concoctions that
supposedly contain mycorrhizae and using them in the garden for plant health. Save your money as these products don’t
really work.
Other things found in soil include protozoa, one celled
animals that are primarily decomposers, invertebrate animals like insects,
slugs and earth worms, which have various roles in the soil ecosystem and
vertebrate animals like moles and mice.
I’ll stop here today. Next week I’ll discuss soil nutrients and
soil pH, very important things for a gardener to know about. For homework read
one of the articles in the links below.
Irish
Spring Cake (LOL)
Here’s an easy but interesting cake for your St. Paddy’s
day meal. Good decorations for the cake include
rainbow or green sprinkles or shamrocks.
The green inner streaking is reminiscent of the fabled soap and the flavor-
well - think green beer.
Ingredients
1 white cake mix
3 large eggs (no need to separate whites and yolks)
Water called for in cake directions
½ cup melted butter
2 cups of lime flavored beer or a light beer with 2
tablespoons lime juice
1 package of lime flavored gelatin
Frosting
½ cup butter, (one stick), room temperature
1 package (8 oz.)
cream cheese, room temperature
3 cups powdered sugar
1 tablespoon lime juice or extract
Green food dye - optional
Directions
Put 1 cup of beer in a small pan and heat it to
simmering.
Add the gelatin and stir until dissolved. Remove from heat.
Add the rest of the beer.
Set aside to cool.
Mix cake mix with eggs, melted butter, and water called
for on box. Beat until smooth and blended.
Pour into a greased 9 x 13 cake pan.
Bake at 350 degrees for about 25 minutes, until a knife
inserted comes out clean.
Let the cake cool to room temperature, cover, and then
refrigerate 1 hour.
Make frosting – blend together cream cheese, butter and
lime juice until smooth and well blended.
Add powdered sugar in 1 cup amounts, blending well until
you have a thick, but spreadable frosting. Add food color gradually, blending after each
addition, until you have the perfect green for you. You may
not need all the powdered sugar.
Refrigerate frosting until ready to use.
Take cake out of the refrigerator and make sure it feels
cool to the touch. With a fork or skewer
poke holes all over the top of the cake.
Pour the beer mixture evenly over the cake, it should
seep into the holes.
Refrigerate cake until the gelatin/beer mix is well
absorbed and gels, at least an hour.
Frost with cream cheese frosting. Refrigerate until served.
 |
| Clover 4Luck Red-Green |
May
the luck of the Irish be with you
Kim Willis
“He who has a garden and
a library wants for nothing” ― Cicero
© Kim Willis - no parts of this
newsletter may be used without permission.
And So On….
Find Michigan garden events/classes
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An interesting Plant Id page you can
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can join on Facebook
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