Abstract: A system for growing plants in spaced apart individual root support beds in elongated U-shaped channels. Each channel has guides for an elongated member to support the root beds above the bottom of the channel and at least one interior duct extending along the length of the channel above the elongated member to deliver cultivation-regulating media through longitudinally spaced outlets. Surplus liquid drains off through the space between the member and the bottom of the channel, carrying away noxious substances from the plants. The top of each channel may be closed by a pair of flexible opaque flaps which yieldingly embrace the stems of plants in the channel to reduce moisture loss and exclude light from the plant roots. The spacing between adjacent channels is varied according to the stage of plant growth, either by arranging the channels in a fixed expanding pattern and moving the plants progressively along the channels or by shifting groups of parallel channels sideways as the plants mature.

Abstract: A plant cultivation and support structure in the form of a strongly hygroscopic block having a flat base, an indentation located in the top large enough to hold a seed or a seed pellet, an open bore leading from the bottom of the indentation to the base, and at least one transverse channel extending clear through the block at the base. A plurality of blocks may be formed in rows and columns of an integral plate subdivided by mutually perpendicular sets of spaced narrow congruent grooves in the top and bottom surfaces of the plate. The material of the plate is a foamed light, brittle plastic having an elongated tandem cell structure with porous walls, a pH value not exceeding 5.2, and specific gravity between 3 and 15 kg/m.sup.3.