Glossary of Terms
O
oblanceolate
Reverse of lanceolate; broadest above the middle and tapering toward the base. Learn more.
oedema (edema)
Swelling or blistering of leaves due to excessive water uptake and poor transpiration. Learn more.
oomycete
Fungus-like microorganisms responsible for diseases such as downy mildew and root rot. Learn more.
open-pollinated
Plants pollinated by natural mechanisms, producing offspring true to type if isolated. Learn more.
organic certification
A process verifying that food or products are produced according to organic farming standards. Learn more.
organic matter
Decomposed plant or animal residues that improve soil fertility and structure. Learn more.
organic mulch
Mulch derived from plant or animal materials such as leaves, straw, or bark. Learn more.
overseeding
Sowing seed into existing turf to thicken coverage or introduce new varieties. Learn more.
overwinters
the ability of an organism or plant to survive through the winter season in a dormant or protected state. Learn more.
oxalate/oxalic acid
a naturally occurring acid in plants; high concentrations can be toxic. Learn more.