You'll be able to obtain at least several of these mulches free or at low cost,
(depending on where you live), and they'll save you much time and money. Mulches
are the biggest money savers in the vegetable garden. By covering the soil
around vegetables with a mulch (a layer of leaves, straw or most any organic or
inorganic material) you will not only increase their yield but reap many other
benefits. Mulches reduce the need for watering and weeding by as much as 95
percent, protect roots of plants against temperature extremes and sudden
changes, and improve the soil and feed plants if organic mulches are used. They
also protect the soil against compaction by traffic, prevent soil erosion on
hills, encourage feeder roots in the rich upper layers of soil, prevent plants
from being splashed with disease spores in heavy rains, reduce pollution caused
by soil applied pesticides, produce carbon dioxide as they decay, and can even
stimulate growth in plants by reflecting light to them. Add to this long list of
benefits earlier maturity of vegetables, larger vegetables, cleaner, less
damaged vegetables and easier harvesting, and it's hard to resist mulching
plants in the vegetable garden.
Mulching has been nature's way of protecting and providing for plants since time
immemorial, the moist, rich, spongy carpet of the forest floor being a perfect
example of mulching. The word mulch itself is an ancient Anglo-Saxon one. Today
mulches are divided into organic materials like leaves and hay, or inorganic
ones like black plastic or aluminum foil. The organic mulches are preferred
because they add nutrients to the soil, whereas the inorganic ones control weeds
better.
Mulches have several minor disadvantages. They do contribute to the holding of
excessive soil moisture on poorly drained soils in wet seasons, which harms
tomato root systems. They can also attract slugs and mice and conceal mole
burrows. But these are usually problems that can easily be solved. Most bad
results from mulching are due to improper applications. Mulch properly once and
you'll never garden any other way.
To begin with, don't mulch early in the spring. Application of organic mulch at
this time will slow up the natural warming of the soil. As an insulating
blanket, organic mulches reduce solar radiation into the soil and, as a result,
frost hazards are greater. So wait until the soil has thoroughly warmed up
before you apply mulch. If you keep a mulched garden from year to year, just
push aside the mulch and plant seed or plants, pulling the mulch back in place
when summer weather arrives.
Before mulching vegetables when the ground is warm, clean out all weeds,
cultivate the ground an inch deep, and water it thoroughly. Then pile organic or
inorganic materials that are insect , disease , and weed free around the plants
to a depth of about four inches. Do not place the mulch closer than a few inches
from the plant stems. As for the materials that can be used for mulches, these
number in the hundreds. Fifty or so are listed below along with their
advantages, drawbacks, and any special ways to apply them. Apply all of these
four inches deep except where noted:
Aluminum Foil - repels some insects, and reflected light from it often increases
yields. Weigh down with stones around plants or cover with a heavier, more
attractive mulch.
Asphalt Paper
- forms a long lasting barrier against weeds, and can be covered
with any more attractive organic mulch.
Bagasse (Chopped Sugar Cane) - long lasting, clean, light colored, and holds
water well. Apply two inches deep. Sometimes sold as chicken litter.
Bark, shredded - lasts a long time, is aesthetically pleasing, adds much humus
to the soil, retains moisture, and will not blow away. Apply two inches thick.
Black Plastic - see Plastic Film.
Buckwheat Hulls - dark, attractive, long lasting, and do not mat but blow away
when dry. Apply three inches thick.
Cloth
- burlap, old rags, old rugs, etc., can be laid between tomato rows if
appearance is not important.
Cocoa
- bean Hulls tend to pack and mold; have a chocolate odor for a few weeks.
Best mixed with other mulches. Apply two inches thick.
Coconut Fiber - hard to get, but long lasting and attractive.
Coffee Grounds - excellent soil conditioner with attractive color, but slightly
acid. Sprinkle a little lime on the grounds.
Compost
- use when only half rotted; cover with other
mulches.
Corncobs, Ground
- need a little nitrogenous fertilizer sprinkled over them; may
attract vermin. Apply two inches thick.
Corn Stalks
- can either be shredded or used whole covered with more attractive
mulches.
Cottonseed Hulls
- good, but hard to obtain.
Dust MuIcb
- this simply means shallow cultivation of the soil to create a layer
of dust that prevents upward movement of water and thus reduces evaporation.
Some experts say all it really does is kill weeds by the act of cultivating.
Excelsior
- a good mulch, long lasting, no packing, and weed free, but highly
flammable. Apply two inches thick.
Fiberglass Matting
- repels insects, is permeable to air and water. A brand
called Weed Chek is widely available.
Glass Wool
- good but tends to blow away unless covered with chicken wire or
other mulch. Apply two inches thick.
Grass Clippings - tests show this is one of the best
mulches to repel nematodes
on tomato roots and increase tomato yield; however, grass clippings will mat,
ferment, and smell if used fresh, and can harbor insects. Use dry grass
clippings three inches thick or mixed with other mulches; if you use the dry
clippings alone, try adding a half cup of blood meal per bushel.
Gravel, Marble, and Quartz Chips - good on their own or for holding down other
mulches, and protect well against mice. Experiments at the Colorado Agricultural
Experiment Station showed that tomatoes mulched with black gravel yielded 10.27
tons per acre, while white gravel mulched tomatoes yielded 8.8 tons, and
unmulched plants yielded 2.86 tons. Black gravel grown plants were also freer of
blossom end rot. The black gravel mulch was applied one and a half inches deep.
Green Manures - cover crops, usually legumes, grown in place and cut for mulch.
Hay - excellent but may need fastening down. Don't use hay going to seed. Apply
six inches thick.
Leaf Mold - rotted leaves, especially nutritious for soil.
Leaves
- oak leaves are the best; avoid types like maple that tend to pack
unless they are shredded first. You can dust oak leaves with a little lime if
you like, but tests show their acidity doesn't affect the pH of the soil when
used as a mulch. Wet down and apply one to two inches thick.
Licorice Root - attractive, nonpacking and long lasting, but flammable and hard
to obtain.
Mushroom Soil, Spent - has good color, benefits garden soil.
Newspapers
- the newsprint repels insects and the wood pulp fertilizes plants,
but newspapers can be unattractive and can form a tight mat so that air doesn't
reach plant roots. Use four to six thicknesses around plants and cover with a
more decorative organic mulch that will also help break the paper down.
Newspaper ashes can be used as a mulch, too.
Peanut Hulls - excellent, but can blow away and may attract vermin.
Peat Moss - dries out and crusts too easily. Must be kept wet or it won't permit
water to reach plants and will even suck water from the soil below to meet its
own needs. Peat moss is best incorporated into the soil, but if it is used as a
mulch, choose chunky types and keep them stirred up and wet. Not recommended for
areas receiving little rainfall if rain is the only source of water.
Pecan Hulls - good mulch but hard to obtain.
Perlite - blows away too easily; must be weighted down with another mulch.
Yields no nutrients.
Pine Needles - attractive and useful, but flammable.
Plastic Film
(Polyethylene) - unattractive but very effective. Black (or green)
plastic is preferred because it doesn't permit weed growth like clear plastic.
Black plastic also absorbs the sun's heat during the day more than organic
mulches do and radiates the heat back faster at night; thus plants mulched with
it are less liable to frost injury than those mulched with organic materials.
Tomato plants, especially, yield more when mulched with black plastic; its chief
disadvantage is that it doesn't improve the soil. Transplant tomatoes into holes
cut through the plastic after it is put down as a mulch. The procedure is
simple. On a windless day soak the ground thoroughly. Mark off the area to be
covered by the plastic, dig furrows four inches deep along the edges of this
space, unroll the plastic, and anchor it in the furrows with soil. Then make
holes in the plastic and set in your transplants. Perforate the plastic for
aeration. Remove the sheet at the end of the growing season and use it again
next year if it's in good condition. Black or green plastic is best in a .0015
thickness and is available from most garden supply stores.
Salt Marsh Hay
- one of the most effective
mulches because it contains no weed
seed, doesn't mat down, and is light and airy. Can be used for many years, as it
doesn't break down quickly.
Sawdust and Wood Shavings - sawdust is a good mulch that is not toxic to plants,
as is often written; however, it does consume a lot of nitrogen in decomposing,
depriving plants of this nutrient. Apply three inches thick and add either a
half cup of blood meal or a cupful of nitrate soda per bushel. Wood shavings
should be treated the same way.
Seaweed
- if you live along the coast, this is a superb, mineral rich, growth
promoting mulch. Can be placed directly around plants or composted first.
Straws - particularly good are wheat and oat straws, which are coarser than hay
but more durable. Straws, however, are more flammable than hay and contain weed
seed. Apply four inches thick.
Rocks and Stone
- attractive, warm up the soil, and add trace elements to the
soil as they imperceptibly wear away. Ring each plant with them a half inch from
the stalk and five inches outward, piling the rocks three inches high. Round,
flat rocks weighing a few pounds are the easiest to work with, but many rocks
and stones can be used. "stones" in a wide variety of shapes can even be made
from cement.
Tobacco Stems - don't use on tomatoes, as they cause mosaic disease.
Vegetable Peelings - good, generally, but don't use old tomatoes or potato
peelings or plants. Tomatoes used as a mulch can cause canker and bacterial
spot; potatoes can introduce verticillium organisms into the vegetable patch.
Compost these waste products instead so that heat will destroy any diseases. One
nurseryman reports that composted tomato vines from the previous year used as a
mulch greatly increased yields.
Water
- in USDA experiments, 6 ml. clear plastic bags filled with water and
placed around tomato plants, increased tomato yields by 20 percent. By absorbing
intense heat from the summer sun at midday and reducing heat loss at night, a
water mulch allows you to plant earlier in the spring and extend your planting
into the late fall. Heated water in the bags warms up the soil even more.
Weeds
- if weeds haven't gone to seed, they can be used as a mulch. So that they
don't root again after a heavy rain, put them atop four or five layers of
newspaper, which is a good way to get rid of two "waste products" at the same
time.
Wood chips
- more attractive than sawdust or shavings, but need the same amount
of nitrogen.
Old Christmas tree branches - make an excellent winter mulch for
evergreens and other foundation Plantings.