Patent Application
20060150508
1. Field of the Invention
The present invention relates to the stabilization of plant containers against wind forces.
2. Background of the Related Art
The production of plants in a container involves many considerations. Beyond simply providing soil, water and sunlight, the efficient nursery production of plants involves optimizing plant growth and health using cost-effective means. Plant nurseries also desire to maintain a wide selection of plant types, varieties, and sizes in order to meet customer needs.
In order to meet these complex and competing production considerations, a nursery operator desires methods and equipment that provide both operational flexibility and efficiency. Accordingly, nursery facilities typically include large outdoor operations where plants are grown in containers to facilitate management of soil, water and sunlight conditions, as well as to facilitate handling of the plant within the nursery and for delivery to market. The containers are commonly set directly on soil or aggregate surfaces, since other complex or permanent structures are not cost-effective. Greenhouses and other protective structures are even more costly, thereby limiting their use. Accordingly, many nursery operations involve production of plants outdoors.
Outdoor nursery facilities must cope with wide variations in weather conditions, including wide changes in ambient temperatures, unpredictable precipitation, and occasional damaging winds. These weather conditions complicate the task of providing each plant with an environment that fosters its growth. For example, plants need water, soil and nutrients, support or stabilization, and sunlight. In addition, plants may benefit from occasional pruning, weeding, fertilizing, and ridding the plant of pests. Each of these considerations must be taken into account in any nursery processes or facilities layout.
Plants with significant height or foliage may be easily blown over with only modest winds due in part to a considerable amount of leverage that can be exerted on the container. For any given wind speed or direction, plants with more height and more foliage are more likely to be blown over. Containerized trees that are several feet tall are particularly subject to being blown over and suffering damage to the limbs or disturbing the root system. An overturned tree can also damage adjacent plants.
Trees and other plants in nature have a network of roots that naturally anchor the plant in soil. However, when the roots and soil are in a container, the plant is no more stable than the container. Typical nursery plant containers or pots have a round base and a sidewall that is either cylindrical or frustoconical. The base is often narrow and the sides are often made of a flexible plastic material. These containers are made frustoconical so they will nest for shipping from the manufacturer to the nursery.
Nursery plant production must also consider the spacing of plants so as to meet the sunlight requirements of particular species and sizes of plants. Whereas a bigger container can, in general, support a bigger plant, it is not effective to rely upon the diameter of the container to establish the spacing of the containers and, therefore, the spacing of the plants. In other words, the spacing of adjacent plants should be considered independently of the size of the container. Furthermore, containers that provide the benefits of air-root-pruning must expose the side walls to air.
Therefore, the stabilization of nursery pots is not a simple matter. The proper spacing must be maintained, the roots must not be disturbed or damaged, and access to the plants must not be overly restricted. A few attempts to stabilize nursery containers are discussed below.
Whitcomb (U.S. Pat. No. 4,793,097) discloses a plant frame that holds multiple containers from blowing over and also protects the container growth medium and root system from temperature extremes. While the frame is effective, the frame can only accommodate containers of a predetermined size and spacing. Furthermore, the frame itself can catch wind and could increase the chances of blowing over.
Loosen (U.S. Pat. No. 5,836,105) discloses a basal stabilizer apparatus to keep containers from blowing over. The apparatus includes a circular base having a central cavity defined by upwardly extending vertical projections attached to the base. There are openings between the vertical projections for placement of stakes for securing the device above the ground. However, the apparatus attempts to stabilize the container by a base with a smaller diameter than the container and providing for staking of the base to the ground. However, the base cavity will only accommodate containers of a given size and shape, the staking of the base reduces operational flexibility, and the vertical sidewalls require that the container be lifted vertically for removal. These considerations limit the practical benefit of the apparatus.
Most recently, Van Reed et al. (U.S. Pat. No. 6,419,195) discloses an array of stabilizing devices, each device having a base and a central upright, hollow, frusto-conical structure with a retention arm adjustably positioned within the top thereof. The object to be retained, such as a plant container, is positioned on portions of the bases of the devices, and the retention arm of each device is positioned over a portion of the object. These devices are cumbersome, time-consuming, and do not accommodate multiple containers as in a nursery setting. Furthermore, the stabilization provided by the devices is believed to be ineffective with a plant having appreciable height.
Therefore, there is a need for an apparatus or system that prevents containerized plants from blowing over in an outdoors nursery production operation. It is desirable that the container stabilization apparatus or system should avoid catching wind. It is also desirable that the apparatus or system should be capable of efficient storage for reuse without disassembly. Preferably, the apparatus or system would not require staking and can accommodate multiple containers. Even more preferably, the apparatus or system would provide operational flexibility and achieve proper plant spacing, physical access, and mobility. Still, the apparatus or system should accommodate the use of lightweight plastic containers of any of a variety of common designs.
The invention provides a plant container system, comprising a rigid spacer defining a perimeter; three or more plant containers disposed about the perimeter of the rigid spacer, each plant container having a rim region; and a plurality of fasteners for firmly securing the rigid spacer to the rim region of each plant container, wherein each plant container is stabilized. Preferably, the plurality of plant containers consists of from 3 to 6 plant containers, most preferably from 3 to 4 plant containers. In certain embodiments, the rigid spacer has a curvilinear shape selected from a circle, square, triangle, polygons, irregular and combinations thereof. Regardless of the shape, the rigid spacer may optionally form a ring, solid sheet, grid, or a combination thereof. In some embodiments, the rigid spacer comprises a bent metal bar, a plurality of metal bars coupled together, or a combination thereof. Further still, the rigid spacer may optionally comprise spokes. In one preferred embodiment, the spacer is essentially planar.
In one embodiment, the containers have at least one hole for receiving a fastener. For example, the plant container might be an air-root-pruning container including a protuberance that provides the at least one hole. It should be recognized that the fasteners may be separate devices, integral to the containers, or integral to the spacer. It is especially beneficial, when the fastener is a separate device, for the spacer to be marked to identify equal spacing around the perimeter.
In accordance with the invention, the plant containers may have any side wall type, including sidewalls selected from smooth, air-root-pruning, root-tip-trapping, and combinations thereof. Furthermore, the plant containers may comprise, without limitation, a rigid pot, a flexible sidewall panel, or a fabric bag. Preferably, the system of containers secured by a spacer is adapted for storage in a nested configuration with another identical system.
The system of the invention may further comprise a second spacer firmly secured to one of the containers and have one or more additional containers firmly secured to the second spacer.
The invention also provides a plant container system, comprising a rigid spacer defining a perimeter; a plurality of container support structures disposed about the perimeter of the rigid spacer and having a rim region firmly secured to the rigid spacer, wherein each container support structure is stabilized by the other support structures; and a plurality of production containers, each production container removably received within one of the container support structures. Optionally, the production containers can be selected from smooth-walled containers, air-root-pruning containers, root-tip-trapping containers, and combinations thereof. Furthermore, the support structure is preferably a support container.
One embodiment of the invention also includes a plant container system, comprising three or more plant containers having a rim region; a first rigid spacer having a first perimeter; and a second rigid spacer having a second perimeter different than the first perimeter, wherein the first and second rigid spacers are interchangeably fastened to the rim regions of the plant containers to provide different spacing of the plant containers. Optionally, each of the plant containers may be a support container adapted to removably receive a production container.
Another embodiment provides a method of stabilizing plant containers, comprising obtaining a rigid spacer having a perimeter that is suitable to position plant containers at a spacing that is appropriate for the plants to be grown in the plant containers; disposing three or more of the plant containers about the perimeter of the rigid spacer; and firmly attaching the rigid spacer to a rim region of each of the three or more plant containers. The method may further comprise setting the containers on an outdoor surface without staking. One method includes detaching one of the plant containers from the rigid spacer.
The present invention provides a plant container system that has sufficient stability to remain upright under strong winds. The system comprises a rigid spacer that defines a perimeter, a plurality of plant containers disposed about the perimeter of the rigid spacer, and a plurality of fasteners for firmly securing the rigid spacer to the rim region of each container, wherein each container has a rim region and is stabilized by the other containers. Accordingly, the spacer secures, couples or links a plurality of containers together in a configuration that stabilized all of the containers.
The spacer is secured to the plurality of containers and distributes forces caused by wind among the containers. The spacer secures the containers together in such a manner that leverages the weight of the containers and their contents to stabilize all of the containers. Essentially, the forces applied against one container are opposed by the other containers. By taking full advantage of leverage, the stability of the containers is significantly improved. Preferably, the containers are equally spaced about the perimeter of the space, but the invention is not limited to equal spacing.
The rigid spacer may have any suitable shape, such as a curvilinear shape selected from a circle, square, triangle, polygon, spokes, irregular and combinations thereof. Regardless of the exact shape, the rigid spacer defines a perimeter that can be easily secured to a plurality of containers. The term “perimeter,” as used herein, means the outer boundary of an object. The perimeter of the spacer may be circumferential, curvilinear, triangular, rectangular, or polygonal. Furthermore, the spacer may enable containers to be secured at any set of points along the perimeter, such as with a circular ring spacer, or only at defined points along the perimeter, such as with a spacer made with spokes. The spacer may be fitted with loops, holes, hooks or other attachment mechanisms to aid in securing it to the rim region of the containers and preventing movement of the container around the spacer.
The rigid spacer preferably has a minimal profile so that the spacer itself does not catch much wind. For example, spokes or a ring with an open central region is generally preferred over a solid plate.
The rigidity of the spacer enables forces to be distributed among the containers. Most common structural materials will have sufficient rigidity to serve this function. For example, the rigid spacer may be made from metal, plastics, wood, composites, or combinations thereof. A metal spacer may be preferred because of its high rigidity, water resistance and durability under a variety of physical and environmental conditions. A plastic spacer may be made that is lighter and more customized for a specific container than a simple metal spacer, but the plastic is preferably treated for stability to ultraviolet light. Suitably, the plastic may be the same as the material used to make the containers. Such materials are well known to those with skill in the art.
In operation, the spacer is secured to a rim region of a plurality of containers disposed about the perimeter of the spacer. The “rim region” is the upper portion of the container sidewall, including the very top and the lip, if any. Reference to a rim region does not imply any specific container wall construction or the presence of a lip. However, the spacer is most usefully secured to the upper most portion of the rim region along the top edge of the container, because the edge is the easiest part of the region to access and a high attachment of the spacer provides the greatest amount of stabilization. If the spacer is being secured to a container already filled with growth medium, the only practical position to secure the spacer is at the uppermost edge of the rim region.
The rigid spacer may be secured to the container in any of a variety of ways. First, it is possible to form the rigid spacer as part of an integral assembly with the containers. Alternatively, the spacer and containers may be secured together with fasteners. Any fastener having suitable strength may be utilized. Specifically, the fastener may be a separate component or a feature of either the spacer or the container. However, preferred embodiments require only minor changes, such as the drilling of a hole, or no change to the container itself.
The fasteners may include, without limitation, plastic cable ties, twisted wire, U-bolts, Velcro straps, elastic bands, screws, clips, rivets or pop-rivets, plastic clamps, or spring steel clamps. The choice of fastener will depend upon the configuration of the spacer. It is also possible for the spacer to be either molded integrally with the containers or affixed with adhesives.
The fasteners may establish a fixed connection or a pivotal connection. For example, a clamp or three-point connection may produce a relatively fixed connection. When the spacer is fastened to the container such that the spacer is not allowed to pivot relative to the container, then the stability is even greater. However, it should be recognized that the rigid spacer and the container walls are not likely to be perfectly stiff and that a certain amount of twisting, bending and somewhat independent movement may occur. On the other hand, a single strap, tie or band would probably allow some degree of pivoting between the spacer and the container. However, a connection that can pivot is not particularly detrimental to the stabilization of the containers, since the connections to other containers constrain the amount of pivoting that the connection will experience.
In one embodiment, the fastening of the spacer to the containers is facilitated by providing at least one hole in each container for receiving a fastener. Such a hole may be provided specifically for the purpose of fastening a spacer to the container or the hole may be a preexisting hole or feature of the container, such as a protuberance of an air-root-pruning container. An exemplary air-root-pruning container is disclosed in U.S. Pat. No. 4,939,865, which patent is incorporated by reference herein.
However, in accordance with the invention, the spacer 12 is positioned to oppose the net force 24 from container 14A and is secured to the other containers 14B, 14C (and in accordance with
As an example supporting further discussion, assume that four containers are connected by a rigid spacer at the top of the container as shown in
Similarly, if the wind blows more or less against the square side of the group of four containers, as the two containers on the down-wind side begin to tilt and lift upward on the inside, the up-wind side of the central spacer is pushed downward and additional pressure is placed on the inner sides of the two up-wind containers.
The terms “plant container” and “plant pot” are used interchangeably herein and are deemed to be synonymous. However, as used herein, the terms “plant container” and “plant pot” should be taken in a broad sense to include a variety of plant container and plant pot types used in plant production, including containers known as air-root-pruning containers and root-tip-trapping containers, both of which may comprise a sidewall panel with or without a base member. A plant container retains a growth medium, such as soil, that is suitable to support root growth.
The terms “comprising,” “including,” and “having,” as used in the claims and specification herein, shall be considered as indicating an open group that may include other elements not specified. The term “consisting essentially of,” as used in the claims and specification herein, shall be considered as indicating a partially open group that may include other elements not specified, so long as those other elements do not materially alter the basic and novel characteristics of the claimed invention. The terms “a,” “an,” and the singular forms of words shall be taken to include the plural form of the same words, such that the terms mean that one or more of something is provided. For example, the phrase “a solution comprising a phosphorus-containing compound” should be read to describe a solution having one or more phosphorus-containing compound. The term “one” or “single” shall be used to indicate that one and only one of something is intended. Similarly, other specific integer values, such as “two,” are used when a specific number of things is intended. The terms “preferably,” “preferred,” “prefer,” “optionally,” “may,” and similar terms are used to indicate that an item, condition or step being referred to is an optional (not required) feature of the invention.
It should be understood from the foregoing description that various modifications and changes may be made in the preferred embodiments of the present invention without departing from its true spirit. The foregoing description is provided for purposes of illustration only and should not be construed in a limiting sense. Only the language of the following claims should limit the scope of this invention.
