Reconstituted natural wood, fabricated by reducing natural wood to fibers and then pressing the fibers together into panels of various thicknesses.
Hardener
Additive used in concrete or any compound to make it set up harder.
Hardening off
The process of gradually acclimatizing greenhouse or indoor grown plants to outdoor growing conditions. Usually used when talking about transplanting of greenhouse plants or seedlings. Can be as simple as moving outside into a protected area for a short time, to more involved methods.
Hardfacing or hard surfacing
Wear-resistant coating of one metal applied by weld overlay to another softer base metal. Alternately it can be applied by insertion of a section of the hardfacing material into a recess in the softer metal. Hardfacing is often used with devices in a high-pressure steam system.
Hardiness
The ability of a plant to withstand low temperatures or frost, without artificial protection.
Hardiness zone
U.S. Department of Agriculture classifications according to annual minimum temperatures and/or lengths of growing seasons. Also referred to as USDA zone.
Hardness
Measure of a materials resistance to dents or scratches.
Hardpan
The impervious layer of soil or clay lying beneath the topsoil. Water will run off and plant roots can not penetrate the layer.Ê Can be broken up.
Hardscape
Includes any garden feature that is not a plant. Like birdbaths, deck, fences, trellises, benches, and patios.
Hardwood
Generally, one of the botanical groups of deciduous trees that have broad leaves in contrast to the conifers or softwoods. The term has no reference to the actual hardness of the wood.
