Ecosystem - a system consisting of a community of animals, plants and microorganisms and the physical and chemical environment in which they interrelate.
Element - a substance that cannot be separated into different substances. All matter is made of elements.
Endophyte - a plant living within another plant. In turfgrasses, it is a fungus within the grass plant secreting substances that repel insect pests.
Epiphyte - A plant that usually grows on another plant and gets its nutrients from the air and water.
Espalier - a plant trained to grow flat against a wall or trellis.
Established - the state of a plant when it is adjusted to the site and thriving.
Evergreen plants - plants that do not drop the current season's leaves at the end of the growing season.
Fallow - cultivated land that is allowed to lie idle for a growing season.
Fertilization - the application of nutrients for plant growth. The union of the egg and sperm.
Fertilizer burn - the browning and in extreme cases, killing of plants from exposure to excessive nitrogen.
Fibrous root - a root system where the roots are finely divided.
Field capacity - the amount of water soil can hold against the force of gravity.
Filament - the part of the stamen that holds the anther in position for pollen dispersal.
Fine fescues - a fine-leaved turfgrass that grows well in shade, low soil moisture, low fertility and low pH. It requires well-drained, slightly dry soils. Red, hard and chewing fescues are included in this group.
Floricanes - on raspberries and blackberries, two-year-old canes which bear fruit and then die.
Food chain - a sequence of organisms in a community in which each member of the chain feeds on the member below it, as in fox, rabbit and grass.
Force - manipulation of environmental factors to make a plant blossom out of season.
Freeze date - The average date of the first hard freeze in the fall /the last hard freeze in the spring.
Friable - easily crumbled or broken
Frond - the leaf of a fern.
Frost - a covering of minute ice needles, formed from the atmosphere at night upon the ground and exposed objects when they have cooled by radiation below the dew point, and when the dew point is below the freezing point.
Frost pocket - a depression in the terrain into which cold air drains, but cannot escape.
Fruiting wood - on grapevine, the one-year-old canes that will produce the current year's fruit.
Fungi - saprophytic and parasitic organisms that lack chlorophyll and include molds, rusts, mildews, smuts, mushrooms and yeast; singular, fungus.
Gametophyte - the phase of a life cycle which has half the normal number of chromosomes.
Genus - groups of closely related species clearly defined from other plants.
Girdling - removing the bark from a woody stem to kill the plant. Encircling a stem with a material so that the cambium layer is destroyed, killing the plant.
Glysophate - A chemical used to kill vegetation; non-specific. Round-up was the first product of this kind for home use, but there are now many other brands and generics available. Works only on actively growing plants by translocation: the plant moves the chemical throughout its system with the result that both roots and tops are killed. If spraying on lawns for weed control, be very sure that they are still completely dormant.
Grafting - the joining of two separate structures, such as a root and a stem or two stems, so that by tissue regeneration they form a union and grow as one plant.
Green manure - an annual cover crop that is turned into the soil before it flowers.
Greensand - an organic source of potassium. About 7% potash plus 32 trace elements.
Grub - short, fat, worm-like larva, especially of beetles.
Guard cells - specialized crescent-shaped cells that control the opening and closing of a stomata.
Gynoecious - has only female reproductive structures; the "female" plant.
Gynodioecious - both female and hermaphrodite plants present. In some plants, strictly female plants are produced by the degeneration of the tapetum, a shell-like structure in the anther of a flower where the pollen cells form.
Harden off - acclimated to the reduced humidity and cooler (or hotter) temperatures of the outdoors
Hardiness - the ability to withstand harsh environmental conditions.
Hardpan - a hard, compacted, often clayey layer of soil through which roots cannot grow.
Hardwood cutting - a mature, woody piece of a woody plant that is removed to asexually propagate a new individual plant.
Heave - the partial lifting of a plant out of the soil as a result of alternating freezing and thawing of the soil.
Heavy metals - the heavy metals of concern to gardeners are lead, zinc, nickel, arsenic, copper and cadmium. These metals can be toxic to plants when they accumulate to high levels in the soil.
Heeling in - covering the roots of dormant plants with soil or mulch for short, temporary periods.
Heirloom vegetables - cultivars that were popular a generation or more ago.
Herbaceous - a nonwoody plant Herbaceous plants are those plants composed of soft tissues. This includes most perennials, annuals, and biennials.
Herbicide - an agent that stops plant growth or kills a plant.
Herbivore - a plant-eating animal.
Hermaphrodite - plants whose flowers have both male and female parts
Hill planting - grouping plants in a cluster, not necessarily on an elevated mound.
Holdfast - a part of a plant that clings to a flat surface.
Honeydew - a sugary substance secreted by aphids and other juice-sucking, plant-feeding insects.
Hoop house - A structure to provide shelter for plants during the winter; constructed of arcs of support material, such as PVC pipe covered with plastic and fastened to the soil; an inexpensive temporary green house.
Horticultural oil - Refined oils which are sprayed on plants to smother pests. The older form, dormant oil, was heavy and had to be used within a very tight temperature range, typically in winter to avoid damaging the plant tissues. The newer superfine horticultural oils, also called ultarfine horticultural oils, are much lighter and have a wider safe temperature range.
Hotbed - a bed of soil enclosed by a structure with a top of glass, heated, often by manure, for forcing or raising seedlings.
Humidity - the amount of moisture in the air.
Humus - brown or black, partially decomposed plant or animal material that forms the organic portion of soil.
Hybrid - a first generation cross between two genetically diverse parents.
Hydrocool - a rapid cooling process of most fresh fruits and vegetables conducted during the immediate harvest in order to maintain the highest quality at its delivery. Other types of cooling delays the time that it takes to reach the consumer and reduces the shelf life.
Hyphae - pl. of hypha; the threads making up the mycelium of a fungus.
Incomplete metamorphosis - gradual growth of an arthropod that involves change in size, but not form.
Incubation - the growth of a pathogen so that it can enter a host.
Indeterminate - growth that is potentially limitless.
Infection - the stage when a pathogen is growing in a host and causing damage.
Inoculant - a microorganism which is introduced into the soil to improve growth of legume crops.
Inoculation - the introduction of a pathogen to a host.
Inorganic - being or composed of matter other than plant and animal; often of mineral origin.
Instar - the stage in the life of an arthropod between molts.
Internode - the area on a stem between nodes.
Interplant - growing two different intermixed crops in an area to maximize space usage.
Interstem - an intermediate stem piece that is grafted between the scion and the stock.
Irrigation - to supply water by artificial means, such as with sprinklers.
Kentucky bluegrass - a cool-season turfgrass that spreads by rhizomes. It is the most popular species for high-quality lawns in Ohio. It is very winter hardy.
Landscape fabric - a loosely intertwined fabric that is placed over the soil as a mulch to reduce weed invasion.
Larva - a stage of insect complete metamorphosis between the egg and pupal stages. The feeding, growing, nonreproductive stage of insect development.
Latent bud - a dormant bud that is capable of growth and development.
Lateral bud - smaller buds on the sides of stems, responsible for growth of leaves and side branches.
Lateritic Soil - any soil produced by the decomposition of the rocks beneath it.
Lath house - a structure consisting of a frame supporting strips of wood which are spaced to provide about 50% shade.
Layering - a method of propagation in which adventitious roots form before the new plant is severed from the parent plant.
Leach - to dissolve in water and wash away.
Leaf miner - A pest of columbine and other plants; visible as white squiggles within the leaves. Controlled by cutting back affected foliage and bagging for trash removal.
Leaf Mold - Leaf mold is a form of compost produced by the fungal breakdown of shrub and tree leaves, which are generally too dry, acidic, or low in nitrogen for bacterial decomposition.
Leaf scorch - injury to leaves due to lack of sufficient water, excessive transpiration or injury to the water-conducting system of the plant.
Loam - Loam is soil composed of sand, silt, and clay in relatively even concentration (about 40-40-20% concentration respectively). Loam soils generally contain more nutrients and humus than sandy soils, have better infiltration and drainage than silty soils, and are easier to till than clay soils. Loams are gritty, moist, and retain water easily.
Long-day plant - a plant that requires a night shorter than its critical dark period, usually 12 hours or less, to develop flowers.
Macronutrients - the nutrients needed in large amounts by plants: nitrogen, phosphorous, potassium, magnesium, calcium and sulfur.
Marginally hardy - close to the limit of hardiness that a plant can withstand. Planting plants that are marginally hardy is risky, because under the most severe conditions for that zone, the plant may not survive without extra protection.
Matted-row - a system of planting where plants are placed off center or are centered on a diagonal.
Meristem - a region of cell and tissue initiation; cells that do not mature, but remain capable of further growth and division.
Metamorphosis - the changes of form insects go through in their life cycle from egg to immature stages to adult.
Microbe - also microorganism; an organism of microscopic size.
Microclimate - the local climate of a small site or habitat.
Micronutrients - the nutrients needed in small amounts by plants: iron, manganese, zinc, copper, molybdenum, boron and chlorine.
Miticide - a pesticide that kills mites.
Mollusk - invertebrate animals with soft, unsegmented bodies, such as clams and snails, usually enclosed in a calcium shell.
Molt - to shed the exoskeleton to accommodate growth.
Monocot - or monocotyledon, flowering plants that have embryos with only one cotyledon.
Monoecious - plants that have both male and female flowers on the same plant.
Moss - small, leafy plants that do not produce flowers or seeds. They grow in moist, shaded areas where fertility is low.
Mycoplasma - disease-causing agents similar to viruses.
Mycorrhiza - The word "Mycorrhiza" is given to a mutualistic association between a fungus (Myco) and the roots (rhiza) of the plants. This ascociation is symbiotic because the relationship is advantageous for both organisms. The macrosymbiont (the plant) gains increased exploration of the soil (rhizo sphere) with the intrincate net of hyphae that increases the uptake of water and nutrients from the soil interphase. The microsymbiont (the fungus) uses the carbon provided by the plant for its physiological functions, growth and development.