Note: Descriptions are shown in the official language in which they were submitted.
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SOD ~L~ FOR ES~RT~T,~TNG PL~iN~S
Field of the Invention
This invention relates to sod mats for establishing
plantings of annual and perennial ornamental and edible
plants.
Backqround of the Invention
The turf grass sod industry holds a preeminent
position among grass growers because economies of scale
allow for extremely efficient production of the product.
Namely, large quantities of turf grass, in the form of a
sod mat, can be easily grown, lifted and transported as
one unit, and replanted at a remote, secondary location.
Growers of plants other than turf grasses have
attempted to emulate the desirable features of grass sod
by constructing various sod-like mats to enable their use
as a planting medium or to be used as a base for seeding
and/or transplanting other plant material. Once the
plants are established, the sod-like mats, along with the
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established plants are intended to thereafter be
transported for replanting. However, all plants do not
have what is required to enable efficient utilization of
the sod-like mats as a planting medium, namely the needed
root knitting characteristic exhibited by grass and which
imparts the required stability to grass sod.
Consequently, in attempts to impart the necessary
structural integrity to such simulated mats and to enhance
their root knitting ability with the plants thereon, the
sod-like mats of the prior art typically include a layer
or layers of wood chips and/or other mulch and an
underlying layer or layers of synthetic anchoring material
such as netting or fabric into which the roots of the
seeded and/or transplanted plants can grow and become
anchored.
U.S. Patent No. 4,941,282 to Milstein requires a
polyester fabric sheet underlaying the planting medium.
U.S. Patent No. 5,224,290 to Molnar et al. discloses a
nylon spunbonded fabric as the sod reinforcement. U.S.
Patent No. 3,863,388 to Loads uses an inert mesh material
as a base for roots to intertwine.
There are several disadvantages to such prior
methods: (a) in constructing the mats it is cumbersome,
time-consuming, and, therefore, expensive to spread out
multiple layers of base material, the sod reinforcement,
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and then the growing medihm; (b) in field growing
conditions it is difficult to obtain an even thickness of
growing medium; (c) the time period required for root
anchoring can vary greatly, depending on environmental
condit.ions and the crop grown, from approximately two (2)
months to one (1) year; and (d) the synthetic anchoring
material is either not biodegradable or is photodegradable
and, in the latter case, most of the material would not
degrade, as it is buried.
Tl~erefore, the objects and advantages of the present
invent:ion are as follows:
[a) to provide a soh mat which has the advantages of
tur~ grass sod, for establishing plantings of annual and
perennial ornamental and/or edible plants and the like,
and especially those having an adventitious or fibrous
root system;
(b) to provide a sod mat in which the knitted and
matted roots of killed grass provide a support or
anchoring system for the fibrous roots of such plants;
(c) to provide a sod mat having a support or
anchoring system which is biodegradable;
- (d~ to provide a sod mat which will anchor plant
roots rapidly, thereby recluiring a shorter time period for
the establishment of such plantings;
(e~ to provide a sod mat for other plants, the
construction and establishment of which is less
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cumbersome, time consuming and expensive than the sod-like
mats of the prior art;
(f~ to provide a sod mat which possesses the
requisite strength and integrity to withstand handling and
transporting, and where such integrity is able to be
maintained even when the sod is placed or attached in a
substantially vertical position;
(g) to provide a sod mat which eliminates the
traditional need of growers and retailers for plant
containers, and provides a convenient method of
transporting and planting already-established plantings
for ornamental purposes; and
(h) to provide a sod mat which can be laid
permanently or temporarily for such ornamental purposes.
Other objects and advantages of the subject invention
will become apparent after considering the following
description and the accompanying drawings~
~ummarY of the Invention
In accordance with the product aspects of the present
invention, the foregoing objects and advantages are
accomplished by providing a sod mat comprising a section
of grass covered surface soil held together by its matted
grass root system, said grass and its roots being dead,
said grass root system being free of substantial
biodegradation or disentanglement of the matted dead grass
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roots, said sod having herbaceous plant propagating
. material implanted in and growing thereon and wherein said
; plant material has a fibrous root system intermeshed with
and supported by said dead grass root system.
In accordance with the method aspects of this
invention, the foregoing objects and advantages are
accomplished by providing a method of establishing a
planting of plant propagating material that is capable of
being ]noved as a unit and reestablished without
signif:icantly disturbing the root systems of the plants.
In particular, the method comprises killing the grass and
grass root system in a section of sod in which the surface
soil i~; held together by its matted grass root system,
and, before substantial biodegradation or disentanglement
of the matted grass root system, implanting in the sod
section plant propagating material of a plant or plants
having a fibrous root system, and allowing said plant
propagating material to develop to the point where the sod
section is stabilized and its integrity can be maintained
by the intermeshing of the plant fibrous root system with
the matted dead grass root system.
Brief De~cri~tion of the Drawinqs
Figure 1 is a perspective view, partly in section, of
the sod mat of this invention, that also illustrates the
process of transplanting plant propagating material such
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as plant plugs, cuttings, root divisions, and/or seedlings
and the like into the sod mat.
Figure 2 is a perspective, partly sectional view of
the sod mat of this invention, that also illustrates the
process of establishing plants within the sod mat by
seeding.
Figure 3 is a cut-away view of the sod mat of this
invention, illustrating the roots of the plant material
intermeshed with the matted, knitted grass roots of the
sod section.
D~tailed Description of the Preferrea Embodiment
Referring to the Figures, the sod mat of this
invention comprises, generally, a section of turf sod 10
(also referred to herein as "sod section" or "turf sod
mat") comprising grass covered surface soil held together
~y its matted grass root system, the turf sod being about
one (1) to about two (2) inches in thickness. The grass
15 of the turf sod is dead; however, the roots 20 of the
dead grass are not substantially biodegraded or
disentangled, such that those matted roots 20 provide the
support and anchoring system for the plant propagating
material 25 and, in particular, the roots 30 of such plant
material, implanted in the sod section.
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~ hile the preferred embodiments set forth herein are
directed to turf sod which has been harvested, it is
- contemplated that the plant propagating material of this
invention may be implanted into sections of turf sod which
have not yet been harvested, and such an embodiment is
intended to be within the scope of this invention.
In preferred embodiments, the section of harvested
turf sod lO is prepared for planting by laying or
positi,oning the sod section or row on a support surface 35
under the root side of the sod section, which is
prefer.1bly impermeable to root penetration. This support
surface 35 may be formed of any suitable material known in
the ar1:, such as concrete, wood, or metal; but preferably
comprises a flexible, plastic sheet material. The plastic
sheeting support surface 35 may be placed on the ground or
elevated on benches, so long as drainage for water is
provided -- either through holes in or sloping of the
surface 35. If production is elevated off the ground, the
surface 35 need not be root impermeable. If production is
on the ground, the surface 35 should be opaque to
eliminate weed growth contamination from underneath.
- Furthermore, the support surface 35 may be used not only
during the growing period as herein described, but, in
certain embodiments, the sheeting or other support surface
under the root side of the sod section may remain with and
be used as a carrier to transport the sod mat. In further
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embodiments, the support surface may remain with the
established sod mat even after planting and re-
establishment of the sod mat, in which case the support
surface is preferably biodegradable.
The grass of the turf sod is to be killed prior to
the implanting of the plant material, as the end-product
of this invention is not a turf grass sod product, but a
sod product having annual or perennial ornamental plants
and herbs and/or other edible plants established and
growing thereon. To kill the turf grass, the turf sod is
preferably treated with a general purpose herbicide such
as glyphosate, available as Roundup~ manufactured by
Monsanto Corporation, which is carried throughout the
grass and its roots but is not active in the soil itself.
The herbicide is applied at a rate recommended for turf
grass. The purpose of the herbicide is to kill the grass,
the grass roots, and any existing weeds. The herbicide
may be applied either within about five (5) days before
harvesting or after the turf sod is harvested. Although
using a herbicide is the preferred means for killing the
grass, an alternative which is understood to be within the
scope of this invention is to kill the grass naturally,
for example, by storing the turf sod in a covered area
until desiccation kills the grass. It is further
contemplated that the grass can be killed either naturally
or chemically and either before or after harvesting the
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turf sod. In either case, the grass blade layer 15, when
dead, functions as a mulch to discourage weed growth.
l'he desired plant propagating material can be
implanted in the sod mat once the herbicide is no longer
active. While the grass itself will not be completely
killed for about fourteen (14) days or more, it has been
found that the desired plant material may be implanted at
any time after about six (6) days, and preferably at any
time after about seven (7) to eight (8) days, from the
time the herbicide is applied. The desired plants can be
propagated by inserting plant propagating material 25 into
the tu~f sod mat 10. This plant propagating material may
include, seeds, transplants, plant plugs, cuttings, root
divisions, seedlings and the like, and the term "plant
propagating material" is intended to include all such
alternatives. Reference number 25 may also represent
other means of starting plants as known in the art, such
as cuttings and viable plant material derived from various
types of plant tissue culture and these other means are,
thus, meant to be included in the "plant propagating
material" definition above.
ReEerring to Figure 1, wherein transplants are the
relevanl_ plant propagating material 25, transplants are
established in the turf sod mat by cutting openings such
as slit~ 40 or holes 45 in the mat slightly larger than
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the diameter of the transplant root mass. Spacing of the
transplants should approximate the diameter of the plants
when mature; depending on the species and cultivar, such
spacing may vary from about six (6) to about twenty-four
(24) inches or more. ~or most ornamental bedding plants,
transp}ants should be spaced about nine (9) to about
twelve (12) inches apart.
Referring to Figure 2, wherein seeds are the relevant
plant propagating material 25, starting plants in the turf
sod mat 10 from seeding may be accomplished in several
ways. For plants such as bedding plants and edible plants
which grow best without competition from neighboring
plants, about two (2) to about four (4) seeds should be
placed together in groups 50. The distance between groups
50 of seeds should be approximately the diameter of the
plants when mature.
The seeds may be placed on top of the layer of dead
grass blades 15 or areas o~ dead grass blades may be
sheared or otherwise removed to expose soil 55 for
improved soil contact. There may additionally, or
alternatively, be provided a layer of growing medium 60
overlying the surface soil and underlying the sown seeds.
Once the seeds have germinated and the first true leaves
appear, the plants should be thinned leaving the single
healthiest or most vigorously growing seedling in each
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group 50. For plants such as wild flowers, which commonly
- grow close together, the seeds may be broadcast seeded
over the surface of the turf sod mat lQ at a density of
about one (1) to two (2) pounds of seed per five hundred
(500) square feet of mat surface area, and th;nn;ng would
not be necessary.
~ lere the seeds can be light germinated, the seeds
may simply be placed or sown on top of the section of sod
or layer of growing medium, without covering with
additional soil or other growing medium. Seeds which
re~uir~ covering to germinate should be covered with a
layer cf growing medium 60 of weed-free humus, compost, or
a commercially prepared mix. The layer of growing medium
60 should be approximately as deep as the diameter of the
seed.
As soon as the plant propagating material 25, e.g.
seeds o:r transplants, are in place on or in the turf sod
mat 10, the mat is moistened and kept moist until
harvested. The plants can be propagated indoors or
outdoors provide~ that the temperature and sunlight
- requirements of plant growth stages are met. The turf sod
mat 10 containing seeds or transplants should be
fertilized by about the third week of production. A water
soluble fertilizer such as Peters Excel 21-5-20 at a
concentration of 200-250 ppm Nitrogen should be applied
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about every three (3) to four (4) weeks. Alternatively, a
slow release fertilizer such as Osmocote 14-14-14
manufactured ~y Sierra Chemical Company may be applied
initially at a rate of approximately 5.5 pounds per 100
square feet with supplemental fertilization with a water
soluble fertilizer as needed.
The plant propagating material 25 of this invention
is importantly that of plants which have a fibrous root
system. The term "fibrous root system" is understood to
include both adventitious root systems and primary root
systems, as well as root systems including creeping
rhizomes; but, in the case of a primary root system, the
primary root must be one which is ~uickly divided into
several or many roots and, in particular, cannot include a
taproot. Importantly, the term "fibrous root system" is
intended to exclude both taproot systems and bulbs, since
such root systems have been found difficult to establish
in the limited depth of the sod mat.
Referring to Figure 3, within about three (3) to four
(4) weeks following germination of the seeds or insertion
of the transplants, the plant roots 30 are sufficiently
knitted and intermeshed into the turf sod mat 10, namely
into the matted grass roots 20 of the sod mat 10, such
that the established sod-mat and plants can be lifted and
transported. This period of time is particularly and
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importantly distinguishable from the sod-like mats of the
- prior art which require at least two (2) to about twelve
(12) m~onths to mature into a sod prior to harvesting or
transporting. Thus, the particular growth period required
prior to transporting the sod mat will be determined by
mar~et re~uirements for the stage of plant maturity,
depending on the particular plants being established on
the ma~, without being limited or constrained by time
periods required for establishing a strong and stable root
system., Experience with growth trials indicates that the
plant growth rates themselves are not significantly
different from those grown by conventional methods,
It has importantly been determined that, due to the
characteristic knitting and intermeshing of the plant
roots with the matted grass roots, the sod mats according
to this invention demonstrate not only distinctive rapid
establishment of stability, but also distinctive strength
and integrity to withstand handling and transporting of
the sod mat as a single unit. Depending on the size and
type of plant grown, the sod-mat may either be rolled or
transported flat; low-growing, flexible plants such as
Nierembergia are not affected significantly by rolling
while a mat containing tall, brittle plants such as mature
Impatiens should remain flat.
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The sod mat may then be established permanently at a
landscaping site or may be temporarily laid indoors or
outdoors, on any surface that will support the mat. In
addition, it has been found that the sod mats of this
invention are uniquely capable of maint~;n;ng the same
strength and integrity which permits the lifting and
transportation as a unit, even when the sod mat is
substantially vertically positioned. Namely, the sod mats
are sufficiently strong to allow attachment to steeply
inclined or substantially vertical surfaces, such as
trellises or pillars, for example, using wire to encircle
the surface or wire stapled through the mat.
The terms and expressions used herein are used merely
as terms of description and not of limitation, and the use
of such terms is not intended to exclude equivalents of
the features shown and described, or portions thereof, it
being recognized that various modifications are possible
within the invention as claimed.
