contour do not entrap particles of planting medium and thereby preclude leakage problems due to misalignment and possible difficult assembly the upper container shell segments 16 are secured into position by means of a split ring 24 residing in a machined or moulded groove 25 shown in fig6 at the topmost edge of the container it is conceiveable that the upper shells could also be secured by one or more external bands as shown at 38 of fig7 vertical seam seals 26 shown in fig5 a thru d utilize splined seals extending the length from the topmost part of the container shell to the base intersection these vertical edge seals provide further restraint of the upper shell to body connection and can be designed as in 5d to be somewhat permanently mounted on one of the faying surfaces while having a capability of being snapped into position on the other surface or a uniform design where they can be snapped onto both mating edges of the upper segments the seals of 5a thru c 27 28 and 29 restrain the shells 16 by utilizing elastomeric or wire reinforced elastomeric spline connectors the base 15 is relieved as at 21 which surface serves as a continuous circumferential lifting groove a number of passages as at 22 around the periphery of the base interior drain off excess water into a trough 23 providing a positive visual means of adequate and through application of plant nutrient fig4 shows an alternative form of the many possible solutions and mechanical equivalents which can be utilized to secure the upper conical shell segments the shell can be modified as in 31 for insertion into the alternative base assembly 32 from the inside out direction as contrasted to the outside in direction of.