Abstract:
Systems and associated apparatus and methods are described for growing plants in a dense and efficient manner in an indoor environment using artificial light. The systems are configured to hold a high density of plants at a relatively close, substantially fixed distance from a light fixture that provides artificial light for growth of the plants. As the plants grow, the plants are transferred to one or more following stations or stages, each of which is configured to hold the now larger plants at the same relatively close, substantially fixed distance from a light fixture. By providing multiple stages to accommodate plant growth, and maintaining the close positioning of the plants to the light fixtures, the impact of the artificial light on the growth of the plants is maximized and the efficiency of the electrical energy use is increased.

Description:
FIELD 
       [0001]    This disclosure relates to systems for growing plants in an indoor environment using artificial lights. 
       BACKGROUND 
       [0002]    In traditional agricultural production methods, plants are grown outside and rely on sunlight for growth. However, the plant growth is subject to drought and other adverse weather conditions, as well as exposure to insects. Although special seed and plant varieties, insecticides, and other chemicals can be used to mitigate plant damage, such measures, if available, increase costs, create environmental damage, and are not wanted by many consumers. Traditional agricultural production methods also consume large amounts of fertile land that are not necessarily available across the globe. 
         [0003]    Previous efforts have been disclosed at growing plants in indoor environments. See U.S. Pat. Nos. 6,604,321; 6,840,007; 7,181,886; 8,104,226; and 7,818,917. 
       SUMMARY 
       [0004]    Systems and associated apparatus and methods are described for growing plants in a dense and efficient manner in an indoor environment using artificial light. The described systems provide more efficient use of land than traditional agricultural production, and allow for indoor growing of plants year round with less water, higher energy efficiency, reduced waste, and low transportation costs. 
         [0005]    The systems are configured to hold a high density of plants at a relatively close, substantially fixed distance from a light fixture that provides artificial light for growth of the plants. As the plants grow, the plants are transferred to one or more following stations or stages, each of which is configured to hold the now larger plants at the same relatively close, substantially fixed distance from a light fixture. By providing multiple stages to accommodate plant growth, and maintaining the close positioning of the plants to the light fixtures, the impact of the artificial light on the growth of the plants is maximized and the efficiency of the electrical energy use is increased. 
         [0006]    In one embodiment, a plant growing system is provided that can include first and second plant growing stations that are arranged next to one another in a horizontal direction. Preferably at least two plant growing stations are provided, but there can be any number of stations more than two if desired. 
         [0007]    The first and second plant growing stations each include a light fixture and a plant support structure that is configured to hold a plurality of plants thereon with the plants facing the light fixture. The light fixture and the plant support structure are mounted to permit relative movement therebetween. The movement can be, for example, rotary movement or linear movement. In one embodiment, the plant support structure can be a rotatable structure and the light fixture is fixed inside the structure, with the structure rotating about the light fixture. In another embodiment, the plant support structure can be a vertical panel that is mounted for movement in a horizontal direction relative to a vertically arrayed light fixture that is fixed in position adjacent to the vertical panel. 
         [0008]    The plant support structure of each of the first and second plant growing stations includes a first surface that in use faces toward its associated light fixture. In the first plant growing station, there is a first substantially constant distance between the light fixture thereof and the first surface of the plant support structure thereof. Likewise, in the second plant growing station, there is a second substantially constant distance between the light fixture thereof and the first surface of the plant support structure thereof. To accommodate plant growth, the first distance is less than the second distance. As the plants grow, the plants can be automatically or manually transferred from the first station to the second station. 
         [0009]    Each succeeding plant growing station increases the distance between the surface of the plant growing structure and the light fixture so as to maintain the same relatively close, substantially fixed distance between the plants and the light fixture of each station as the plants grow. 
         [0010]    In another embodiment, a plant growing station that is usable in a plant growing system is provided. The station can include a light fixture and a plant support structure that is configured to hold a plurality of plants thereon with the plants facing the light fixture. The light fixture and the plant support structure are mounted to permit relative movement therebetween. The plant support structure includes a first surface that in use faces toward the light fixture with a substantially constant distance therebetween, a second surface opposite the first surface and that is exposed to ambient air, and a plurality of holes formed through the panel from the interior surface to the second surface. In use of the plant growing station, root balls of the plants are held in the holes with the plants facing the light fixture and the root balls of the plants exposed so they can receive air and water. Exposing the root balls to ambient air helps to air prune the roots of the plants so they have less root mass, which reduces plant waste and helps to stress the plants correctly to produce better aroma and flavor. 
         [0011]    Nutrient enriched water for the plants can be provided via aquaponics (i.e. the process of raising fish, using fish waste converted with bacteria into nitrogen to fertilize plants hydroponically and returning clean water back to the fish tanks where the cycle repeats itself) or hydroponics where the nutrients are mixed into the water at a suitable point in the process. Water supplied through aquaponic methods have an added benefit of release carbon dioxide that is produced by the aquatic animals, such as fish, directly where the plants are, eliminating the need for a carbon dioxide generator. Nutrients and carbon dioxide are consumed by the plants and the water is returned back to the aquaponic system to repeat the process. 
         [0012]    The system described herein can be used to grow many different types of plants. Examples of plants that can be grown include, but are not limited to, leaf lettuce, herbs, water cress, oregano, asian greens, bibb lettuce, oak leaf lettuce, romaine lettuce, thyme, salad mixtures (for example red and green lettuce, etc.), kale, broccoli, basil, spinach, and arugula. 
     
    
     
       DRAWINGS 
         [0013]      FIG. 1   a  illustrates a plant growing system described herein including multi-station rotary and vertical plant growing systems, and an aquaponic system. 
           [0014]      FIG. 1   b  illustrates a plant growing system described herein including multi-station rotary and vertical plant growing systems, and a hydroponic system. 
           [0015]      FIG. 2  is a perspective view of the rotary plant growing system looking from the end containing the final station. 
           [0016]      FIG. 3  is an end view of the rotary plant growing system looking from the end containing the initial station. 
           [0017]      FIG. 4  is an end view of the rotary plant growing system looking from the end containing the final station. 
           [0018]      FIG. 5  is an elevated side perspective view of the vertical plant growing system. 
           [0019]      FIG. 6  is an end view of the vertical plant growing system looking from the end containing the initial station. 
           [0020]      FIG. 7  is an end view of the vertical plant growing system looking from the end containing the last station. 
           [0021]      FIG. 8  is a close-up view of a top portion of the initial station. 
       
    
    
     DETAILED DESCRIPTION 
       [0022]    With reference initially to  FIG. 1   a,  an exemplary plant growing system  10  described herein is illustrated. The system  10  can include a water supply  12 , one or more rotary plant growing systems  14 , and/or one or more vertical plant growing systems  16 . The plant growing systems  14 ,  16  can be used separately or together in combination. Each plant growing system  14 ,  16  is fluidly connected to the water supply  12  which supplies water to the respective system. In the illustrated example, the water supplied by the water supply  12  is nutrient enriched water to facilitate plant growth in the systems  14 ,  16 . Unused water from the systems  14 ,  16  can be returned back to the water supply  12 . 
         [0023]    In use, either or both of the plant growing systems  14 ,  16  can be disposed within an enclosed building, such as a warehouse. Typically, the building will be enclosed such that plants on each system  14 ,  16  will not be (or will at least minimally be) exposed to direct sunlight. Therefore, light for growth of the plants will primarily or entirely be provided by artificial lighting sources and/or redirected solar energy sources that are exposed to each system  14 ,  16 . If both systems  14 ,  16  are used, the systems can be located in the same room of the building or in separate rooms. 
         [0024]    The water supply  12  can be located in the same building as the systems  14 ,  16 , such as in the same room(s) or in a room separate from the systems  14 ,  16 . Alternatively, the water supply  12  can be located outside the building containing the systems  14 ,  16 , such as in a different building or in the open environment. 
         [0025]    In the illustrated example of  FIG. 1   a,  the water supply  12  is illustrated as being formed by an aquaponic system although a hydroponic system illustrated in  FIG. 1   b  can be used together with or separate from the aquaponic system. In the aquaponic system, fish are raised in one or more tanks  20 . Nutrient enriched water for the plants is created using fish waste that is converted with bacteria into nitrogen to fertilize the plants hydroponically. Nutrients and carbon dioxide are consumed by the plants and the water is returned back to the aquaponic system to repeat the process. The construction and operation of aquaponic systems for generating nutrient enriched water are known in the art. The fish raised in the tanks  20  can also serve as a food source. 
       Rotary Plant Growing System 
       [0026]    With reference now to  FIGS. 2-4 , an exemplary embodiment of the rotary plant growing system  14  is illustrated.  FIG. 1   a  shows four of the systems  14  grouped together to form two separate rotary plant growing units, with each unit having two systems on a lower level and two systems on an upper level. However, any number of units having any number of individual systems  14  can be deployed. 
         [0027]    As best seen in  FIG. 2 , the system  14  includes a plurality of plant growing stations  22   a,    22   b, . . . n  arranged next to one another in a horizontal direction. It is preferred, but not required, that the system  14  include at least two plant growing stations. In the illustrated example, there are five plant growing stations, but a larger or smaller number of plant growing stations can be used. In addition, instead of arranging the stations horizontally, the stations can be arranged next to one another in a vertical direction. 
         [0028]    The plant growing stations are arranged side-by-side adjacent to one another, with the station  22   a  being an initial or first stage station, which is followed by the station  22   b,  which in turn is followed by the station  22   c,  which in turn is followed by the station  22   d,  and finally by the final station  22   n.  The initial station  22   a  is configured to receive plants to be grown where the plants are germinated to have an initial size and have roots to hold the growing media together. However, in appropriate circumstances, seeds could be used. As the plants progress through the stations  22   a, b, . . . n,  the plants increase in size and at the final station  22   n,  the plants reach a size suitable for harvesting the plants. It should be apparent that the number of plant growing stations used will depend on factors such as the growth rate of the plants, the type of plants being grown, and the amount of light, among others. 
         [0029]    Each plant growing station  22   a, b, . . . n  comprises a structure  24  that is rotatable about a central axis A-A. The structure  24  can have any shape that one finds suitable for growing plants as described herein. In the illustrated example, each structure  24  can be generally cylindrical, although other shapes can be used. Each structure comprises a circular frame  26  at each end of the structure  24  with radial spokes  28  that connect the frame  26  to a central hub  30 . A plurality of, for example four, longitudinal support beams  29  extend in a longitudinal direction parallel to the axis A-A between the frames  26  at each end. 
         [0030]    Plant support structures  32 , in this example four curved quarter panels  34   a, b, c, d,  are removably attached to one another and are supported at their ends by the frames  26  and along their top and bottom edges by the beams  29 . The beams  29  include brackets  31  (two of which are visible in  FIG. 2 ) that are configured to releasably clamp the panels  34   a - d  to the frames  26  and the beams  29 . 
         [0031]    Each of the quarter panels  34   a - d  is configured to hold a plurality of plants thereon with the plants facing radially inward toward the axis A-A. As best seen in  FIGS. 2-4 , each panel  34   a - d  is formed with a plurality of holes  36  in which root balls of plants  38  can be held. The holes  36  extend through the panels  34   a - d  from a first, inwardly facing surface  40  that in use faces inwardly toward the axis A-A to a second, outwardly facing surface  42  that faces outwardly. 
         [0032]    Each of the plant growing stations  22   a, b, . . . n  further includes a light fixture  46  associated therewith that provides the light for plant growth. The light fixtures  46  are disposed inside of the respective structures  24  and the light fixtures  46  extend a length of the structures  24  sufficient to provide light to the plants for plant growth. In the illustrated example, the light fixtures  46  extend substantially the entire axial length of the associated structure  24 , although other constructions can be used as long as adequate light for growth is provided. 
         [0033]    The light fixtures  46  are fixed in position within the structures such that the structures  24  rotate about the light fixtures. However, the light fixtures  46  can be rotatable and the structures  24  fixed such that the light fixtures rotate relative to the structures  24 . In any event, the light fixtures and the structures are mounted to permit relative movement, in this case rotational movement, therebetween. Relative rotation ensures that all the plants on the structures and facing inward toward the light fixtures are exposed to a sufficient amount of light energy for plant growth. 
         [0034]    In the illustrated example, each of the light fixtures  46  comprises a plurality of elongated fluorescent bulbs  48  that extend substantially the length of the respective structure and which are evenly radially spaced from the axis A-A and are equally circumferentially distributed from one another about the axis A-A. Other suitable light energy sources can be used. As discussed below, the number of bulbs  48  in each of the light fixtures  46  varies from station to station, with the number of bulbs generally decreasing from the first station  22   a  to the final station  22   n.  With reference to  FIGS. 3-4 , in each of the stations  22   a, b, . . . n,  the distance D between the inwardly facing surface  40  of the structure and the respective light fixture  46  of that station is substantially constant. However, the distance D increases in each station starting from the station  22   a,  with the distance D 1  ( FIG. 3 ) in the station  22   a  being the smallest and the distance Dn ( FIG. 4 ) in the station  22   n  being the largest. Between the station  22   a  and the station  22   n,  the distance D of the respective stations increases. The increase in the distance D in each station accommodates the growth in the plants in each station so that the distance between the canopies of the plants being grown and the light fixture  46  remains generally constant in each station. The distance D and the spacing of the plant canopy from the light fixture can vary based on the type of plant species being grown. 
         [0035]    In one embodiment, the plants are exposed to generally the same amount of light in each station. As the distance D increases (i.e. the diameter of the light fixture  46  decreases) and the plant canopy gets larger, the number of the bulbs  48  used in the light fixture  46  in each station can change so that the plants are exposed to generally the same amount of light in each station. For example, the station  22   a  can include, for example, sixteen bulbs  48 , while the station  22   n  can include, for example, eight bulbs  48 . However, other techniques can be used to expose the plants to generally the same amount of light in each station, such as using different types and/or sizes of bulbs in the stations, controlling how long the bulbs are on in each station, and the like. In one embodiment, the light fixtures  46  are controlled by a timer that is adjustable so that the plants are exposed to the appropriate daily light integral for the particular plant species. 
         [0036]    Returning to the structure  24 , the panels  34   a - d  are detachably connected to one another and to the structure using the brackets  31 . As the plants  38  grow they are transferred from one station to the next station by removing each panel, and installing it on the next station after the panels of the next station have been removed and transferred to its following station. If the station is the last station, the panels are removed for harvesting the plants. 
         [0037]    Instead of removing the panels and transferring to a new station, in one embodiment it is possible to change the diameter of the light fixture in a station and keep the panels fixed in that station until the plants are ready for harvest. In this embodiment, multiple stations or a single station could be used, since the panels would remain in place and the diameter of the light fixture changed. The light fixture diameter could be changed by changing the diameter of the installed light fixture as the plants grow, or by removing the light fixture and replacing it with a new light fixture having a different diameter. 
         [0038]    With reference to  FIGS. 2 and 4 , the structures  24  are rotated via a suitable drive mechanism(s)  50 . Any drive mechanism(s)  50  that is capable of rotating the structures  24  can be used. In the illustrated example, the drive mechanism  50  includes an electric motor  52  mounted on a support frame structure  54  of the stations. The electric motor  52  has an output shaft fixed to a drive pinion that drives a drive chain  56  that extends around a drive gear  58  that is fixed to a shaft  60  that extends the length of the system  14 . Along its length, the shaft  60  includes drive sections  62  that are engaged with the periphery of one of the circular frames  26  to rotate the frames  26  and thus rotate the structures  24 . 
         [0039]    It is preferred that the structures  24  are rotated by the drive mechanism  50  at a constant speed. The particular speed can depend on a number of factors, including the specie of plant being grown, the amount of light provided by the light fixtures, and other factors. In one example, the rotation speed can be 1 revolution every 35 minutes. The inventor has found that this speed results in proper air root pruning of the root balls of the plants which are exposed to atmosphere on the exterior of the structures  24  so that the plants have less root mass, reducing waste and stressing the plants correctly to produce better aroma and flavor. In general, the slower the rotation, the more root pruning that occurs. In another example, the rotation speed can be between 1 revolution every 30 to 45 minutes. In a hot dry climate, a faster rotation speed may be appropriate to prevent the roots from drying out. 
         [0040]    In the illustrated example, each station is rotated at the same speed. However, in another embodiment, the stations are separately driven and rotated at different rotation speeds. 
         [0041]    The support frame structure  54  is a rectangular structure that can be stackable and/or arranged side-by-side and bolted together as shown in  FIG. 1 . The structure  54  also has adjustable feet  70  along its length to allow for height and slope adjustment of the system  14 . 
         [0042]    As shown in  FIGS. 2-4 , each station also includes a water feed trough  72  into which nutrient rich water from the water supply  12  is fed. The bottom of each structure  24  is disposed in the trough so that the root balls of the plants are dipped into the water in the troughs  72  as the structures are rotated. The troughs  72  of each station can form one continuous trough, or the troughs can be separate from one another but fluidly connected so that nutrient rich water flow from one trough to another. The troughs  72  are sloped downwardly from the final station  22   n  to the first station  22   a,  so that nutrient rich water from the water supply  12  is initially fed into the trough of station  22   n  where plants are larger and require more water, the water then flowing through each successive trough of the remaining stations until flowing into a collection basin for return to the water supply  12  after flowing through the station  22   a.    
         [0043]    In one exemplary use of the system  14 , plants to be grown are transplanted into the holes  36  in the panels  34   a - d.  The panels are then mounted to the structure  24  of the first station  22   a.  The remaining stations  22   b, c, . . . n  are either empty or have panels containing larger plants that started out at the first station  22   a.    
         [0044]    The structures  24  and the light fixtures are then rotated relative to one another about the axis A-A at a constant rate. As the structures rotate, they dip the root ball ends of the plants into the troughs  72  to feed moisture to the plants. At the end of the determined growing time interval, the rotation is stopped, and the panels are shifted forwardly one station by removing the panels and mounting them on the next station. The panels from the final station  22   n  are removed and the plants thereon harvested. This process is repeated until the panels initially on the first station  22   a  have been installed on the final station and rotated the desired time interval to achieve the desired harvest height. Panels from which plants have been harvested are cleaned and new plant transplants are inserted into the holes so that the panels can be reinstalled on the first station. The time interval is a function of plant growth. If the nutrients are correct and there is the right light and light time, plants grow faster. If humid, plants take in less and grow slower, so the interval varies based on the environment, the plant species, plant health and other plant factors. 
       Vertical Plant Growing System 
       [0045]    With reference now to  FIGS. 5-8 , an exemplary embodiment of the vertical plant growing system  16  will now be described. As best seen in  FIG. 5 , the system  16  includes a plurality of plant growing stations  122   a,    122   b, . . . n  arranged next to one another in a horizontal direction. It is preferred, but not required, that the system  16  include at least two of the plant growing stations. In the illustrated example, there are twenty eight of the plant growing stations, but a larger or smaller number of plant growing stations can be used. 
         [0046]    The plant growing stations are arranged side-by-side adjacent to one another, with the station  122   a  being an initial or first stage station, which is followed by the station  122   b,  which in turn is followed by additional stations including the final station  122   n.  The initial station  122   a  is configured to receive plants to be grown where the plants are germinated to have an initial size and have roots to hold the growing media together. However, in appropriate circumstances, seeds could be used. As the plants progress through the stations  122   a, b, . . . n,  the plants increase in size and at the final station  122   n,  the plants reach a size suitable for harvesting the plants. It should be apparent that the number of plant growing stations used will depend on factors such as the growth rate of the plants, the type of plants being grown, and the amount of light, among other factors. 
         [0047]    Each plant growing station  122   a, b, . . . n  comprises a stationary support frame  124  that extends along a longitudinal direction A-A. The support frame  124  includes a plurality of vertical support poles  126 , a plurality of lower horizontal supports  128 , and a plurality of upper horizontal supports  130  along the length of the frame  124 . Plant support structures  132 , in this case a plurality of movable vertical panels  134   a, b, c, d,  are suspended in a vertical orientation from their top ends in a manner described further below. 
         [0048]    Each of the panels  134   a - d  is configured to hold a plurality of plants thereon with the plants facing toward a light fixture described further below. As best seen in  FIGS. 7-8 , each panel  134   a - d  is formed with a plurality of holes  136  in which root balls of plants  138  can be held. The holes  136  are formed in what can be termed inwardly facing surfaces  140  of the panels that in use face inwardly toward the light fixture. The surfaces  140  are inwardly facing in that they face inwardly toward the light fixtures. 
         [0049]    In the illustrated example, the panels  134   a - d  are double-sided panels in that the panels  134   a - d  have holes  136  formed on each of its sides. However, the panels  134   a,    134   d  have plants  138  mounted on only one side thereof facing the light fixtures, while the panels  134   b,    134   c  have plants  138  mounted on each side thereof. It is to be realized that the panels  134   a - d  need not have holes  136  on each of their sides. In addition, the hole spacing can vary based on the species of plant being grown. 
         [0050]    Each of the plant growing stations  122   a, b, . . . n  further includes one or more light fixtures  146  associated therewith that provides the light for plant growth. In the illustrated example, three separate light fixtures  146  are provided, one light fixture  146  between the panels  134   a,    134   b,  a second light fixture  146  between the panels  134   b,    134   c,  and a third light fixture  146  between the panels  134   c,    134   d.  The light fixtures  146  are identical in construction to each other. 
         [0051]    In the illustrated example, each of the light fixtures  146  comprises a plurality of vertically arranged elongated fluorescent light bulbs  148 , where each bulb extends substantially the entire vertical height of the panels  134   a - d.  In addition, for each of the light fixtures  146 , the individual bulbs  148  are evenly spaced from one another in the longitudinal direction A-A. The number of bulbs  148  in each of the light fixtures  146  can be the same in each station. The light fixtures  146  are supported from longitudinal supports  149  that extend in the A-A direction. 
         [0052]    With reference to  FIGS. 6-7 , in each of the stations  122   a, b, . . . n,  the distance D between the inwardly facing surface  140  of the panel and the respective light fixture  146  of that station is substantially constant. However, the distance D increases in each station starting from the station  122   a,  with the distance D 1  ( FIG. 6 ) in the station  122   a  being the smallest and the distance Dn ( FIG. 7 ) in the station  122   n  being the largest. Between the station  122   a  and the station  122   n,  the distance D of the respective stations increases. The increase in the distance D in each station accommodates the growth in the plants in each station so that the distance between the canopy of the plants being grown and the light fixtures  146  remains generally constant in each station. The specific distance D and the spacing of the plant canopy from the light fixture can vary based on the type of plant species being grown. 
         [0053]    In one embodiment, the number of bulbs in each station is the same and the plants are exposed to generally the same amount of light in each station. However, other techniques can be used to expose the plants to generally the same amount of light in each station, such as using different types and/or sizes of bulbs in the stations, controlling how long the bulbs are on in each station, and the like. In one embodiment, the light fixtures  146  are controlled by a timer that is adjustable so that the plants are exposed to the appropriate daily light integral for the particular plant species. 
         [0054]    The panels  134   a - d  and the light fixtures  146  are mounted so that they are movable relative to each other in the direction A-A from the station  122   a  to the station  122   n.  In particular, the panels  134   a - d  are mounted so as to be movable relative to the light fixtures  146  in the direction A-A. 
         [0055]    With reference to  FIG. 8 , the panels  134   a - d  are movably suspended on longitudinal supports  150  that extend in the A-A direction. In the illustrated example, the supports  150  are generally hollow, and have a slot  152  running the length thereof. The top end of each panel  134   a - d  includes a plurality of roller assemblies  154  formed by a pair of wheels rotatably mounted on pins that extend upwardly through the slot  152 . The roller assemblies  154  allow the panels  134   a - d  to slide relative to the supports  150  so that the panels can be moved from station to station in the direction A-A from the station  122   a  ultimately to the station  122   n.  In one embodiment, the panels are pushed manually from station to station, but an automated transport mechanism, such as one similar to a dry cleaners storage rack, could be utilized. 
         [0056]    It is preferred that the panels reside at each station a predetermined time depending upon the plants being grown. For example, in one embodiment, the panels are moved to the next station every day. At the end of the predetermined time period, the panels are moved to the next station. With respect to the last station  122   n,  the plants are ready for harvest at the end of the predetermined time so the panels are removed and the plants harvested therefrom. 
         [0057]    An irrigation system is provided for feeding nutrient rich water to the plants  138 . In particular, with reference to  FIG. 6 , a water feed line  156  is fluidly connected to the water supply  12  to receive nutrient rich water therefrom. The water feed line  156  feeds the water to water lines  158  that are disposed within and run the length of the supports  150  ( FIG. 8 ). The water lines  158  include openings or other means of discharging the water within the supports  150 . The discharged water flows through the slots  152  in the supports  150  and falls onto the top ends of the panels  134   a - d  where a collector system resides to distribute water evenly throughout the panel ( FIG. 8 ). The panels  134   a - d  are generally hollow structures with water channels inside and with openings  160  at the top through which the water can flow into the interior of the panels. The water passes through the panels  134   a - d,  wetting the root balls of the plants  138 . The water then exits the bottom of the panels through suitable openings and falls into gutters  162  disposed beneath each of the panels  134   a - d  ( FIG. 7 ). The gutters  162  run the length of the system  16  and discharge into a collector  164  ( FIG. 7 ) for return to the water supply  12 . The gutters  162  are sloped downwardly from the first station  122   a  to the final station  122   n  so that the water flows via gravity to the collector  164 . 
         [0058]    The irrigation system can be divided into zones depending upon the water pressure needed for each station. In one embodiment, each zone has a specific time to distribute water through that section based on the physical needs of the plants in the specific zone. At the end of the specific time, the water to that zone is shut-off and water started to the next zone. In addition, suitable manual or electro-mechanical valves can be provided for controlling the water flow, which is pumped by a pump from the water supply  12 . An irrigation controller can be provided which controls when water is provided. The controller can start the pump and open the valves to allow water to flow, and shut off the pump and/or close the valves when sufficient water has been provided. In another embodiment, water can be provided at the same time to each zone. 
         [0059]    In one exemplary use of the system  16 , plants to be grown are transplanted into the holes  136  in the panels  134   a - d.  The panels are then mounted to the supports  150  of the first station  122   a.  The remaining stations  122   b, c, . . . n  are either empty or have panels containing larger plants that started out at the first station  122   a.    
         [0060]    The growing time interval for each station can be the same or different. Also, the rows of panels can move at the same time interval, or certain rows can move faster or slower than the other rows, depending on the growth of a specific plant species in each station or row. For example, oregano grows slower, and asian greens grow faster. 
         [0061]    During a predetermined growing period, the plants are exposed to light from the light fixtures  146  and watered by the irrigation system. Once the growing period is completed, the panels are moved to the next station by rolling the panels along the supports  150  using the roller assemblies  154 . The panels from the final station  122   n  are removed and the plants thereon harvested. This process is repeated until the panels initially at the first station  122   a  have reached the final station and have achieved the desired harvest height. Panels from which plants have been harvested are cleaned and new plant transplants are inserted into the holes so that the panels can be reinstalled on the first station. 
         [0062]    The examples disclosed in this application are to be considered in all respects as illustrative and not limitative. The scope of the invention is indicated by the appended claims rather than by the foregoing description; and all changes which come within the meaning and range of equivalency of the claims are intended to be embraced therein.