Medicinal plant in the context of Erasmus House

Overexploitation, also called overharvesting or ecological overshoot, refers to harvesting a renewable resource to the point of diminishing returns. Continued overexploitation can lead to the destruction of the resource, as it will be unable to replenish itself. The term applies to various natural resources such as water aquifers, grazing pastures and forests, wild medicinal plants, fish stocks, and other wildlife.

In ecology, overexploitation describes one of the five main activities threatening global biodiversity. Ecologists use the term to describe populations that are harvested at an unsustainable rate, given their natural rates of mortality and capacities for reproduction. Such practices can result in extinction at the population level and even extinction of whole species. In conservation biology, the term is usually used in the context of human economic activity that involves the taking of biological resources, or organisms, in larger numbers than their populations can withstand. The term is also used and defined somewhat differently in fisheries, hydrology, and natural resource management.

De materia medica (Latin name for the Greek work Περὶ ὕλης ἰατρικῆς, Peri hulēs iatrikēs, both meaning "On Medical Material") is a pharmacopoeia of medicinal plants and the medicines that can be obtained from them. The five-volume work was written between 50 and 70 CE by Pedanius Dioscorides, a Greek physician in the Roman army. It was widely read for more than 1,500 years until supplanted by revised herbals in the Renaissance, making it one of the longest-lasting of all natural history and pharmacology books.

The work describes many drugs known to be effective, including aconite, aloes, colocynth, colchicum, henbane, opium and squill. In total, about 600 plants are covered, along with some animals and mineral substances, and around 1000 medicines made from them.

The history of herbalism is closely tied with the history of medicine from prehistoric times up until the development of the germ theory of disease in the 19th century. Modern medicine from the 19th century to today has been based on evidence gathered using the scientific method. Evidence-based use of pharmaceutical drugs, often derived from medicinal plants, has largely replaced herbal treatments in modern health care. However, many people continue to employ various forms of traditional or alternative medicine. These systems often have a significant herbal component. The history of herbalism also overlaps with food history, as many of the herbs and spices historically used by humans to season food yield useful medicinal compounds, and use of spices with antimicrobial activity in cooking is part of an ancient response to the threat of food-borne pathogens.

Alkaloids are a broad class of naturally occurring organic compounds that contain at least one nitrogen atom. Some synthetic compounds of similar structure may also be termed alkaloids.

Alkaloids are produced by a large variety of organisms including bacteria, fungi, plants, and animals. They can be purified from crude extracts of these organisms by acid-base extraction, or solvent extractions followed by silica-gel column chromatography. Alkaloids have a wide range of pharmacological activities including antimalarial (e.g. quinine), antiasthma (e.g. ephedrine), anticancer (e.g. homoharringtonine), cholinomimetic (e.g. galantamine), vasodilatory (e.g. vincamine), antiarrhythmic (e.g. quinidine), analgesic (e.g. morphine), antibacterial (e.g. chelerythrine), and antihyperglycemic activities (e.g. berberine). Many have found use in traditional or modern medicine, or as starting points for drug discovery. Other alkaloids possess psychotropic (e.g. psilocin) and stimulant activities (e.g. cocaine, caffeine, nicotine, theobromine), and have been used in entheogenic rituals or as recreational drugs. Alkaloids can be toxic (e.g. atropine, tubocurarine). Although alkaloids act on a diversity of metabolic systems in humans and other animals, they almost uniformly evoke a bitter taste.

Agroforestry (also known as agro-sylviculture or forest farming) is a land use management system that integrates trees with crops or pasture. It combines agricultural and forestry technologies. As a polyculture system, an agroforestry system can produce timber and wood products, fruits, nuts, other edible plant products, edible mushrooms, medicinal plants, ornamental plants, animals and animal products, and other products from both domesticated and wild species.

Agroforestry can be practiced for economic, environmental, and social benefits, and can be part of sustainable agriculture. Apart from production, benefits from agroforestry include improved farm productivity, healthier environments, reduction of risk for farmers, beauty and aesthetics, increased farm profits, reduced soil erosion, creating wildlife habitat, less pollution, managing animal waste, increased biodiversity, improved soil structure, and carbon sequestration.

Pharmacognosy is the study of crude drugs obtained from medicinal plants, animals, fungi, and other natural sources. The American Society of Pharmacognosy defines pharmacognosy as "the study of the physical, chemical, biochemical, and biological properties of drugs, drug substances, or potential drugs or drug substances of natural origin as well as the search for new drugs from natural sources".

The traditional kitchen garden, vegetable garden, also known as a potager (from the French jardin potager) or in Scotland a kailyaird, is a space separate from the rest of the residential garden – the ornamental plants and lawn areas. It is used for growing edible plants and often some medicinal plants, especially historically. The plants are grown for domestic use; though some seasonal surpluses are given away or sold, a commercial operation growing a variety of vegetables is more commonly termed a market garden (or a farm). The kitchen garden is different not only in its history, but also its functional design. It differs from an allotment in that a kitchen garden is on private land attached or very close to the dwelling. It is regarded as essential that the kitchen garden could be quickly accessed by the cook.

Historically, most small country gardens were probably mainly or entirely used as kitchen gardens, but in large country houses the kitchen garden was a segregated area, normally rectangular and enclosed by a wall or hedge, walls being useful for training fruit trees as well as offering shelter from wind. Such large examples very often included greenhouses and furnace-heated hothouses for more tender delicacies, and also flowers for display in the house; an orangery was the ultimate type. In large houses, the kitchen garden was typically placed diagonally to the rear and side of the house, not impeding the views from the front and rear facades, but still quick to access. In some cases, hardy flowers for cutting were grown outside there, rather than in the flower garden. A large country house hardly expected to buy any vegetables, herbs or fruit, and the surplus was often distributed as presents; the walled example at Croome Court in England covers seven acres, and the gardens have a large "Temple Greenhouse", an orangery in the form of a Roman Temple.