Plant cultivation devices and methods
BACKGROUND 
     This invention relates to improved methods and devices for cultivating young plants. 
     In the cultivation of young plants for homes or gardens, the usual procedure at present is to plant seeds or tiny seedlings in relatively small flower pots or similar containers and to subsequently transplant the young plant into bigger containers as the plant grows larger. The transplanting procedure involves not only labor but also a risk of damage to the plant. The alternative procedure of planting a seed or tiny seedling in a full-sized container to start with has the disadvantage of resulting in excessive dilution of vital nutrients during the critical early stages of a plant&#39;s life. 
     SUMMARY OF THE INVENTION 
     It is an object of my invention to permit the planting of seeds or tiny seedlings in a full-sized container or piece of ground in which the full-grown plant is intended to be located, so as to obviate the need for transplanting procedures, while assuring retention of nutrients near the seed or seedling. 
     It is a further object of my invention to provide a simple and inexpensive means of assuring the retention of most nutrients near and around a seed or seedling planted in a full-sized container or piece of ground. 
     It is yet another object of my invention that said means be preferably reusable for the cultivation of other young plants, and that it be adaptable for use with plants of various sizes and in various stages of their growth. 
     It is still a further object of my invention to provide a simple and inexpensive means for minimizing the risk of damage to those plants which may have to be transplanted for whatever reason. 
     Briefly, my invention consists of temporarily inserting a substantially impervious material close to and around a seed or young plant to assure retention of most nutrients in the immediate vicinity of said seed or plant. Small perforations within said material permit drainage of excess water and of metabolic waste products. Indentations along lines joining said perforations facilitate breakage, tearing or cutting of the material to appropriate size. A sharp leading edge may be provided along the perforations and indentations to facilitate insertion of the material into the soil around the seed or plant. Said material may be tubular in form or may be in form of a sheet adaptable to being bent into a cylindrical or conical configuration. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     My invention may be best explained with reference to the drawing, in which: 
     FIG. 1 is a schematic cross-sectional view of one embodiment of my invention; 
     FIG. 2 is a partial front view of the perforated tube of FIG. 1; 
     FIG. 3 is a partial cross-sectional view of an alternative embodiment of my invention; 
     FIG. 4 is a perspective view of the cone-like insert 7 of FIG. 3; 
     FIG. 5 is a partial front view of the perforated sheet used to form insert 7; and 
     FIG. 6 is a partial magnified view of section S--S or S&#39;--S&#39; of FIG. 2 or FIG. 5. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In FIG. 1 is shown a flower pot 1 filled with soil 2 and containing a young plant or seed 3 embedded in the upper central portion of the soil. A tube 4 having perforations 5 disposed as shown in FIG. 2 and broken or cut off along one of the indentations 6 of FIG. 2 is pressed into the soil 2 so as to enclose the seed 3 and to reach all the way down to the base 8 of the flower pot, thereby forming an inner compartment 9. Most of the nutrients around seed 3 are thereby retained within compartment 9. The perforations 5 in tube 4 permit drainage of any excess water from compartment 9. 
     As the plant grows bigger, the first and smallest tube 4 may be withdrawn and replaced by a similar tube of the next larger size. Subsequently, as the plant continues to grow, it may be enclosed by tubes of successively larger sizes until the plant is fullgrown. A set of tubes of increasing sizes may be provided for this purpose. 
     In the alternative preferred embodiment of my invention shown in FIG. 3, a young plant or seed 3 embedded in soil 2 is surrounded by an insert 7 formed of a piece of stiff but flexible sheet 10 (FIG. 5) bent into the cone-like configuration of FIG. 4. Drainage of excess water from the inner compartment 9 enclosed by insert 7 is then provided by either the perforations 5 in sheet 10 or by an opening 11 near the apex of the inverted cone 12 obtained by wrapping sheet 10 into the form of a truncated cone instead of a full cone, as indicated in FIG. 4. Of course, sheet 10 may also be shaped into a cylinder, and inserted in FIG. 1 in lieu of the tube 4. 
     The sheet 10 or tube 4 may be made of a metal, such as iron or aluminum, or out of a large variety of plastic materials, such as polyvinyl, nylon, polyethylene, polypropylene, or of any other suitable material. To permit easy adjustment of tube 4 or sheet 10 to the required length or width, indentations 6 are formed along lines joining the perforations 5, as indicated in FIGS. 2 and 5. To facilitate breakage or cutting of tube 4 or sheet 10 along any of the indentations 6, and to provide a sharp leading edge 15 or 16, 17 for easy insertion into the soil 2, the indentations 6 are preferably in form of asymmetric V-shaped grooves, each groove comprising a short and steep side 20 and a long and shallow side 23, as shown in the magnified partial cross-sectional view of FIG. 6A. 
     As indicated in FIG. 6B, the long and shallow side 23 of groove 6, terminates in a sharp edge when tube 4 or sheet 10 is cut off, torn off or broken along the deepest portion 19 of groove 6. A similar edge 18 may be provided around the perforations 5 to assure a continuous sharp leading edge. Insertion of tube 4 or sheet 10 into soil 2 is thereby facilitated. 
     Although the indentations 6 are preferably disposed along lines joining the perforations 5, as shown in FIGS. 2 and 5, they may also be disposed in any other convenient pattern. Neither is it necessary to provide all the perforations shown in FIGS. 2 or 5 to start with. It may suffice to have such perforations precut in tube 4 or sheet 10, and let the user make as many perforations as necessary by pushing out the precut portions. 
     As the plant grows bigger, the insert 7 may be withdrawn without disturbing the soil around the plant by exerting a gentle pulling action on the trailing edge 21 and on the upper edge 22 of FIG. 4. Thereafter, a somewhat larger enclosure may be formed by either bending the same piece of material into a wider cone or by using a larger piece of material. Subsequently, as the plant keeps growing, the last insert may again be replaced by a larger insert, and this procedure may be repeated several times until the plant is fullgrown. 
     The conical enclosure may also be used to minimize the risk of damage to the plant during any necessary transplantation, e.g., when a young plant is purchased from a nursery. The contents of the enclosure may then be kept undisturbed within the cone during the transplantation process, after which insert 7 may be withdrawn and replaced by a larger insert as outlined above. 
     There will now be obvious to those skilled in the art many variations and modifications of the afore-described embodiments which, however, shall remain within the scope of my invention if defined by the following.