In this essay, I will attempt to use Louden's descriptions of garden positions as closely as possible. That means that you will encounter some amazing punctuation and sentence fragments, but I am trying to keep the tone of Loudon's early 19C definitions. Where the definition in America differed from the English usage, I have altered the description to reflect American usage.
Apprentice Gardener. Youths intended for serving to learn the trade of gardener, are placed under master or tradesmen gardeners, for a given period, on terms for mutual benefit: the master contracting to supply instruction, & generally food & lodging, or a weekly sum as an equivalent; & the parents of the apprentice gardener granting the services of the latter during his apprenticeship as their part of the contract. The terms agreed on is generally 3 years; or more if the youth is under 16 years of age but whatever may be the period, by the laws as to apprentices it must not extend beyond that at which the youth attains the age of manhood. Few can expect to attain to the rank either of master-gardener or tradesman, who has not served an apprenticeship to the one or the other. In general, it is preferable to apprentice youths to master-gardeners, as their the labor is less than in tradesmen's gardens, & the opportunities of instruction is generally much greater.
Journeyman Gardener. The period of apprenticeship being finished, that of jouneyman commences, & ought to continue till the man is at least 25 years of age. During this period, they ought not to remain above 1 year in any one situation; thus, supposing they have completed apprenticeship in a private garden at the age of 21, & that the ultimate objective is to become a head-gardener, they ought first to engage themselves a year in a public botanic garden; the next year in a public nursery; that following, they should again enter a private garden, & continue making yearly changes in the most eminent of this class of gardens, till they meet with a situation as head gardener. The course to be followed by an apprentice intended for a tradesman-gardener is obvious; having finished his period in a private garden, let him pass through a botanic & nursery garden, & then continue in the most eminent of the class of public or tradesmen's gardens, to which they are destined.
Garden Foreman. In extensive gardens where a number of hands are employed, they are commonly grouped or arranged in divisions, & one of the journeymen of longest standing is employed as foreman to the rest. Wherever 3 or more journeymen are employed, there is commonly a foreman, who has a certain extent of authority at all times, but especially in the absence of the master. This position confers a degree of rank to the garden foreman for the time being, but none afterwards.
Head Gardener. A head gardener is a master who has apprentices or journeymen employed under him. Out of a supervising position & working again as a journeyman, they retain the rank & title of master-gardener, but not of head-gardener.
Nursery Foreman. The nursery foreman is entrusted with the numbered & priced catalogues of the articles dealt in; authorized to make sales; entrusted to keep an account of men's time, & as a consequence, this entitles the holder to the rank of head-gardener, while so engaged, & to that of master-gardener ever afterwards; the same may be said of foremen in public botanical gardens & other public gardens.
Traveling Gardener. Traveling gardeners are sent out as a collectors of plants along with scientific expeditions; they are generally chosen from a botanic garden; & their business is to collect gardening productions of every kind, & to mark the soil, aspect, climate &c. in which they have been habituated.
Botanic Garden Director or Curator. Botanic curators superintend the culture & management of a botanic garden; maintain an extensive correspondence with other botanic curators; exchanges plants, seeds, & dried specimens, so as to keep increasing their garden's collection of living plants & herbarium siccum.
Public Gardener. Gardener employed to oversee the gardens & grounds at a publicly-owned building or a facility operated for the good of the public, such as a church or hospital or institution.
Contract Gardener. Contracting gardeners, or new-ground workmen, are jobbers on a larger scale. They undertake extensive works, such as forming plantations, pieces of water, roads, kitchen gardens, & even greenhouses, hot-houses, & other garden structures & buildings.
Seed Grower. Seed-growers are as frequently farmers as gardeners; they contract with seed-merchants to supply certain seeds at specified rates, or to raise or grow seeds furnished to them by the seedsmen on stipulated terms.
Seed Merchant. Seed merchants sell incidental seeds at their place of business, where they carry other products for sale as well.
Herb Gardeners. They grow herbs, either the entire herb, as mint, or particular parts, as the bulb of lilium, & the flower of the rose for medical purposes, or for distillation as perfumery.
Physic Gardeners or Herbalists. They grow herbs for the purpose of medicine, or perfumery, but also collect wild plants for these purposes. Formerly, when it was the fashion among medical men to use indigenous plants as drugs, this was a more common & important branch of trade. Now, they have commonly shops appended to their gardens, or in towns, in which the herbs are preserved, & sold in a dried state.
Collectors for Gardens. The first variety of this grouping is the gipsy-gardeners, who collect haws, acorns, & other berries & nuts, & sell them to the seedsmen; the next are those who collect pine & fir cones, alder-catkins, & other tree-seeds, which require some time, & a process to separate the seeds from their covers, & clean them before they can be sold; & the highest variety are those gardeners who establish themselves in foreign countries, & there collect seeds & roots, & prepare dried specimens of rare plants for sale.
Market or Truck Gardeners. Market gardeners grow culinary vegetables & also fruits; the simplest kind are those who grow only the more common hardy articles for the kitchen, as cabbage, pease, turnips, &c. a higher variety grow plants for propagation, as cauliflowers, celery, & artichoke-plants, & pot-herbs, as mint, thyme; & the highest variety possess hot-beds & hot-houses, & produce mushrooms, melons, pines, & other reed articles & exotic fruits.
Florist. Florists are either market florists who grow & force flowers for the market, & those who grow only hardy flowers to be cut as nosegays, & those who deal chiefly in exotics or green-house plants to be sold in pots. Another is the select florist, who confines himself to the culture of bulbous-rooted & other select or florists' flowers, who has annual flower-shows, & who disposes of the plants, bulbs, tubers, or seeds.
Botanic Gardener. Botanic gardeners devote themselves exclusively to the culture of an extensive collection of species for sale; these may be limited to indigenous kinds. Botanic gardeners also collect & dry specimens of plants, & also of mosses, fungi, alga & offer them for sale: to this they often join the collecting of insects, birds, & other animals.