completed and reinforced by upper longitudinal members 32 33 fastened to posts 15 17 and 16 18 by screws 34 the legs and posts may be formed of wooden members rigidified plastic members or metal members the posts 15 18 are arranged to both support the individual shells 20 and to permit end to end abutment of contiguous frames 10 and shells 20 the shells 20 include web portions 36 37 which are fastened to the upper surfaces of the frame 10 by screws 38 39 to complete an individual planter 40 as shown in fig2 and comprising the fundamental elements of a module for creating extra long u201c macro u201d linear planters 100 fig9 of lengths more than several hundred feet each module comprised of a half pipe shell 20 supported by a skeletal frame 10 the short planter 40 of fig2 is exemplary of the fundamental elements found in the u201c macro u201d planter 100 of the invention comprised of a large series of frames 10 and shells 20 juxtaposed end to end as shown in fig8 and 9 the planters 40 and 100 are clad in accordance with the invention with vertical outer panels 50 of translucent plastic arranged in spaced relation with inner reflective or opaque panels 51 to form a circumscribing light box 53 closed at its top by horizontal translucent panels 52 fig5 and fig9 more specifically as shown in fig4 upper and lower l shaped clips 60 are fastened at their distal ends to the frame 10 the bent ends 61 of the clips engaging and securing the cladding panels 50 51 to the frame 10 the translucent panels 52 are secured by epoxy cement not shown to the upper edges of the.