#82 - Nov 2024 - Garden Stuff - © Sandy Lang - slang@xtra.co.nz DEATH November: Last month of spring. Lots to do in the garden. Nature’s abuzz with new life - but death’s busy too. Leaving aside untimely death through disease and injury, death’s common across all living organisms. It’s in the DNA. It’s a key part of life itself. Cell death: Your skin’s largely dead cells, your hair too - likewise, fur, feathers, claws, nails, hooves, horns, scales and beaks. Cell death’s no accident but planned. Google programmed cell death (PCD). Plants: Death’s even more common in plants. It includes not just cell death, but tissue death, organ death and whole-plant death. Tissues: Phellem - The bark of a tree is made up of dead cells - cork. Like your skin, it forms a tough, waterproof barrier between the fragile tissues (inside) and the hostile world (outside). The bark cells die, having first accumulated large quantities of the waterproofing compound, suberin. New bark cells are continuously produced (inside) and old dead ones eroded or actively discarded (outside). Xylem - The wood of a tree is mostly dead cells. The wood serves both as a conduit for sap moving from root to leaf and for structural support. The xylem cells die having first accumulated large quantities of the stiffening compound, lignin. The wood is continuously produced (outside) while the old wood (inside) continues its structural function but ceases to carry sap after a few years (sap wood vs heart wood). Organs: Plant growth is unlike animal growth. Plants produce a whole range of temporary structures (organs) including leaves, petals and fruit. These serve for a while before being killed off and discarded - shed. Shedding: Organ shedding is intentional. The old organ doesn’t just fall off. It’s by the growth of a fragile barrier (abscission layer) between the plant and the organ which severs the vascular connection with the plant. Deciduous leaves serve just a few months before shedding, evergreen leaves a bit longer (see www.mulchpile.org/50). Petals are shed only about 3 days after flower opening, surplus tiny fruitlets are shed about 2 weeks later, mature fruit about 5 months later. Twigs, branches: Most trees shed twigs, most forest trees shed whole branches – self-pruning. An abscission layer grows. The twig/branch dies. It falls off. Whole plants: Annual and biennial plants are DNA programmed to grow, flower, seed, then die. If you stop one of these fruiting, it will live much longer. Cut off dead flowers. Don’t let them fruit. ___________________________________