Straw vs. Hay Mulch - In the battle to
control weeds and add fertility and improve the water retention of
your soil, is one really better than the other? Well in a word...Yes!
Let's start at the beginning. What is
the difference between straw and hay or are they essentially the same
thing? Many people think they're identical as
they're both often tied into square or rectangular bales but a closer
look reveals that they're actually quite different.
Understanding these differences may help in your decision of which
material better suits your gardening needs.
Straw is the stalk of a cereal crop
such as oats, barley, wheat or rye after harvesting has removed the
seed heads. Usually a big machine called a combine harvester will
come along into the field and in one smooth operation it chops off
the top portion containing the grain and sends it in one direction
for processing then cuts the straw and collects it until a bale sized
block is formed and then it's automatically tied and drops out of the
machine back onto the field for later collection. In many parts of
the world straw is seen as a waste product, a secondary by-product of
the cereal crop, and is sold for practically nothing. But where I
live in Nova Scotia, Canada it is actually more expensive to buy
straw than it is to get hay because not much straw is produced
locally and what we have is quickly purchased for animal bedding. We
just don't have the climate for mass cereal crop production.
Hay refers to grass that has been cut
while green, dried and then made into square or round bales. Hay is
used mainly for feeding animals when no fresh grass is available and
it provides bulk and fibre to their diets as well as sugars and
nutrients. The best hay smells sweet and if you took a handful and
got it wet would still look like grass. Straw almost exclusively has
a uniform yellow colour once it's baled and just a hint of smell
whereas hay bales can look like a greenish coarse grass, fine grass,
or even flowery and weedy grass, it entirely depends on what plants
were cut and dried to make them. The quality can vary hugely
depending on the skill of the farmer making the bales and the quality
of his hay fields. Getting the hay dried to the optimum level so that
it's not crumbly but is dry enough to discourage mold growth is very
important as it quickly starts to compost if it's damp and composting
hay bales have been known to heat up and start barn fires.
So now that you know the difference
between straw and hay...why choose one over the other for your
garden? I mean it's just mulch right? The benefits of mulch in a
garden cannot be overstated, and if you're reading this article I
assume you already know how terrific it is for controlling weeds,
providing walkways, and helping the soil to remain cool and moist
longer in summer and insulating it in colder weather. Mulch creates a
micro climate over your soil by essentially acting as a blanket to
protect it from the harsh drying effects of the sun and wind. All
mulches perform this action including our straw and hay, but did you
know that other mulches used around the world have included wood
chips, bark, shredded leaves and even rocks? Yes, rocks. The
inhabitants of Easter Island recognized that mulching prevented the
wind and rain from eroding the valuable topsoil so they used volcanic
rocks spaced out on their fields as a lithic mulch to slow runoff and
wind erosion. But I can't imagine most of us deliberately placing
rocks in the garden, can you? I know that in my own garden I'm
constantly doing the opposite because every year my garden seems to
grow a new supply of rocks.
Surely some of these mulching methods
work better than others wouldn't you think? Do some work better in
areas of wind or rain? Are some better suited for slopes? What about
availability? These are all questions you need to answer for yourself
and then experiment and see what actually works for you. Planning is
a huge part of having a successful and productive garden over the
long term. You should choose the location wisely taking into account
the sunlight, type of soil, and the climate. But in reality most of
us just have to use whatever we've got. Not everyone has 20 acres and
can pick the perfect spot. So let's just say that you are growing in
a typical home garden and the mulches you can most easily and
economically get are hay and straw.
The Pros of Straw
Straw is a terrific insulator. The
hollow stems retain air and their chopped light fluffy texture allows
for easy spreading. In fact the principal uses in the US over the
past 200 years have been for animal bedding and for insulating walls
in homes (or building straw bale houses) and for covering the ice in
ice houses to act as the insulation so the ice is available for use
during the summer. When used in a garden it also tends to remain
lighter and fluffier than hay and keeps a beautiful golden appearance
for quite a long time. The surface remains dry even as the lowest
layers touching the soil begin to decompose. Have you ever picked
strawberries in a field? Almost certainly there was straw around the
bushes and it gave you a good clean place to sit or kneel that felt
soft and cushioned.
The Cons of Using Straw
Straw can be expensive depending where
you live and you may not be able to grow it yourself. Straw can also
act as a home to rodents because of its fluffy texture and has a
higher tendency to blow away in strong winds when it is first laid
unless you try very hard to pack it down. Straw does add some bulk to
your soil but is mostly cellulose and fiber left over after the plant
put all it's nutrients into the seed heads that were harvested.
Consequently it adds fewer nutrients back into the soil when it
decomposes and soil borne bacteria tie up available nitrogen for
longer to break down the tougher stalks. Because straw is fluffier
and makes less direct contact with the soil it takes longer to
decompose, which is both a plus and a minus. If you want to add
nutrients it's a minus but if maintaining a cover and walkway is
important then it's a plus. Weeds are more easily able to push
through a straw mulch from the bottom due to it's fluffy nature, but
blown in weeds also won't land in a moist environment so they do not
sprout. You can counteract this effect of weed push through by
weeding and putting down some newspaper before laying the straw mulch
and then using a thicker layer, perhaps 8 inches thick or more, to
provide a darker environment that most weeds simply don't have the
energy to get through.
The Pros of Hay
Hay is readily available and it's
possible to get a scythe and cut your own if you have a grassy area
on your property. You don't need to bale it just cut it, let it dry,
and then fork it into your wheel barrow and wheel it over to where
it's needed. Even long grass clippings can function the same way as
hay because they're essentially the same thing. Hay left over from a
previous year is often considered garbage by farmers who want to feed
their animals the most recent and more nutritious hay and
consequently it's sometimes available for free during hay season in
the summer. You can find it by looking at your local online
advertisement site such as kijiji or craigslist or by asking your
farming friends. Hay contains a variety of grasses and legumes plus
often clover and other flowers including both the leaf and stalk and
so the plant nutrients are all there. When hay decomposes it adds
significant nutrients to the soil to increase it's fertility and it
adds a balanced ration of NPK as well as all the trace minerals that
were contained in the plant. Hay tends to lay flat and pack down so
it decomposes fairly quickly and has more of a sponge effect than
straw does which means that in heavy rainfalls it buffers or slows
down the amount of rain that soaks into the soil to help prevent
erosion and leeching of nutrients. Because hay packs down the weeds
from underneath get smothered and die very quickly, but weed seeds
that blow in can sometimes sprout, especially in an older hay mulch
which is very damp.
The Cons of Hay Mulch
Hay mulch has more of a tendency in
moist parts of the world to harbour slugs and snails so you need to
keep a good eye out for them and have a method of removal although it
generally doesn't harbour mice as it's too dense. Hay takes on a
packed and spongy texture that holds water so sitting or kneeling
after wet weather is likely to still see you get a wet bum. It holds
moisture allowing seeds on top to sprout (which is why hay bale
gardening is such a great thing) but if you're trying to suppress
weeds do you want this? And often the hay itself contains seeds that
will sprout once they get wet so you could end up with a living
pathway until the dry weather dries out the topmost layers of your
mulch again. As hay decomposes it is broken down by various bacteria
and other organisms that all use nitrogen, the same for the
decomposition of straw. So what happens is that they get a new food
source (your hay compost) and the bacteria multiply rapidly which
depletes the soil of nitrogen. As they run out of food they die and
the nitrogen is once again available for the plants to use, so
planting directly into a hay mulch without any supplemental nitrogen
source available probably isn't the best idea.
So now that you know more about hay
and straw as mulch, which one are you going to choose? In a perfect
world the solution is to use both. A thick layer of hay mulch on the
bottom where it will decompose and act as a spongy reservoir for
moisture topped off with a few inches of straw that will be a dry
layer preventing blown in weeds from sprouting and giving you a
lovely dry golden walkway. But we don't all live in a perfect world
do we? We're just trying to make the best of what we've got, and
that's what makes a great gardener or homesteader, the ability to
problem solve. So I'd suggest that if you have a choice of only one
type of mulch that you use hay simply for the fertility it will add
to your soil. But as all practical gardeners know, you use what you
have or can easily get. Why pay money for straw if a local farmer
will give you hay in July for nothing? If you can get it free but
don't need it all at once then simply put them out by your garden,
throw a tarp over the bales and save it for next year, and if it gets
a bit wet and starts to compost itself it doesn't really matter, it's
all going in the soil in the end anyways and the pile of bales can
act as a wind break while it waits to be used.
A garden is a living, breathing thing.
It evolves from year to year and as gardeners we are the stewards of
the fertility that is in our soil. It depends on us to pay attention
and make sure that we don't take out more than we put back in. After
all, we want our gardens to feed us for many years to come and to be
places where we can teach our children and grandchildren the
mysteries of growing their own food too. Gardens are places where
families and communities come together to work, talk and visit so we
should try and make sure that in addition to teaching the value of
work that we also find pleasure in being outdoors. Planning the best
method of mulching your garden is important not only for fertility
and moisture retention, it will significantly lower the amount of
watering and weeding you have to do which in turn increases your
enjoyment of your garden and is better for the precious water
resources that are becoming scarce in so many places. As a fellow
gardener I encourage you to try new things and experiment with
mulches to see what works for you. But most of all, have fun in the
garden!
So what do you think? Send me a comment.
Well written informative post with no errors that I can see.
ReplyDeleteThanks...I try.
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