Plant nursery
A nursery is a place where plants are propagated and grown to a desired size. Mostly the plants concerned are for gardening, forestry, or conservation biology, rather than agriculture. They include retail nurseries, which sell to the general public; wholesale nurseries, which sell only to businesses such as other nurseries and commercial gardeners; and private nurseries, which supply the needs of institutions or private estates. Some will also work in plant breeding.
A nurseryman is a person who owns or works in a nursery.
Some nurseries specialize in certain areas, which may include: propagation and the selling of small or bare root plants to other nurseries; growing out plant materials to a saleable size, or retail sales. Nurseries may also specialize in one type of plant, e.g., groundcovers, shade plants, or rock garden plants. Some produce bulk stock, whether seedlings or grafted trees, of particular varieties for purposes such as fruit trees for orchards or timber trees for forestry. Some producers produce stock seasonally, ready in the spring for export to colder regions where propagation could not have been started so early or to regions where seasonal pests prevent profitable growing early in the season.
Nurseries
There are a number of different types of nurseries, broadly grouped as wholesale or retail nurseries, with some overlap depending on the specific operation. Wholesale nurseries produce plants in large quantities which are sold to retail nurseriesWholesale nurseries may be small operations that produce a specific type of plant using a small area of land, or very larger operations covering many acres. They propagate plant material or buy plants from other nurseries which may include rooted or unrooted cuttings, or small rooted plants called plugs, or field grown bare root plants, which are planted and grown to a desired size. Some wholesale nurseries produce plants on contract for others which place an order for a specific number and size of plant, while others produce a wide range of plants that are offered for sale to other nurseries and landscapers and sold as first come first served. Retail nurseries sell plants ready to be placed in the landscape or used in homes and businesses.
Methods
Propagation nurseries produce new plants from seeds, cuttings, tissue culture, grafting, or division. The plants are then grown out to a salable size and either sold to other nurseries that may continue to grow the plants out in larger containers or field grow them to desired size. Propagation nurseries may also sell plant material large enough for retail sales and thus sale directly to retail nurseries or garden centers.Nurseries may produce plants for reforestation, zoos, parks, and cities. Tree nurseries in the U.S. produce around 1.3 billion seedlings per year for reforestation projects.
Nurseries grow plants in open fields, on container fields, in tunnels or greenhouses. In open fields, nurseries grow decorative trees, shrubs and herbaceous perennials. On a containerfield nurseries grow small trees, shrubs and herbaceous plants, usually destined for sales in garden centers. These have proper ventilation, sunlight etc. Plants may be grown by seeds, but the most common method is by planting cuttings, which can be taken from shoot tips or roots.
Conditioning
With the objective of fitting planting stock more able to withstand stresses after outplanting, various nursery treatments have been attempted or developed and applied to nursery stock. Buse and Day, for instance, studied the effect of conditioning of white spruce and black spruce transplants on their morphology, physiology, and subsequent performance after outplanting. Root pruning, wrenching, and fertilization with potassium at 375 kg/ha were the treatments applied. Root pruning and wrenching modified stock in the nursery by decreasing height, root collar diameter, shoot:root ratio, and bud size, but did not improve survival or growth after planting. Fertilization reduced root growth in black spruce but not of white spruce.Important factors for nursery production
For a nursery to produce healthy crops, they must manage many factors, a few of them being irrigation, landscape topography, and soil conditions of the site.Irrigation
Plants need water to grow. Water needs will vary depending on plant species, weather, and soil. An example is in Ontario, irrigation water is used most in late spring and in summer, when plants need water most, and based on climate patterns in Ontario, this time is also when there is the least amount of rainfall. Some nurseries will create water sources by building a dam, or changing a watercourse. or building manmade ponds. The water source and water pumps should to be close to fields In this situation, water will need testing for pH, and testing for chemicals in the water to ensure an acceptable water quality. Two common types of irrigation systems are drip irrigation, and overhead irrigation.Landscape topography
A good slope for a plant nursery is 1–2 degrees. Any more than 5 degrees will make the nursery susceptible to soil erosion. The nursery stock should be planted in rows running across the slopes. If the landscape of the nursery has sections of land where erosion could occur, the nursery needs to come up with a solution such as by using erosion prevention structures like rip rap. Topography impacts nursery design and layout and it is a factor in strategizing what direction to plant rows. It also impacts where windbreaks should be planted. If an area has a flat slope and is open, it will need a windbreak.Soil conditions
For a nursery to produce healthy crops, it will need to have healthy soil. The soil should have good drainage and nutrient holding capacity. Soil testing will help a nursery find out its pH levels, and also the amounts of nutrients in the soil. To test soil drainage, one method is to dig an 18" deep hole that is at least 4" in diameter. Fill the hole with water, and leave it for an hour. This will allow the soil to saturate. Next, fill the hole with water again but leave the top 2" of soil in the hole without water. Wait an hour then return to the hole with a measurement tool like a ruler to find out how much water has drained from the hole. The corresponding measurements will allow the tester to decide what type of drainage capacity their soil has. If the water level drops 1/2" or less it is poor draining. If water drops 1/2" to 1", it drains at a medium rate. 1"< means that the soil drains quickly.Hardening off, frost hardiness
Seedlings vary in their susceptibility to injury from frost. Damage can be catastrophic if "unhardened" seedlings are exposed to frost. Frost hardiness may be defined as the minimum temperature at which a certain percentage of a random seedling population will survive or will sustain a given level of damage. The term LT50 is commonly used. Determination of frost hardiness in Ontario is based on electrolyte leakage from mainstem terminal tips 2 cm to 3 cm long in weekly samplings. The tips are frozen then thawed, immersed in distilled water, the electrical conductivity of which depends on the degree to which cell membranes have been ruptured by freezing releasing electrolyte. A −15 °C frost hardiness level has been used to determine the readiness of container stock to be moved outside from the greenhouse, and −40 °C has been the level determining readiness for frozen storage.In an earlier technique, potted seedlings were placed in a freezer chest and cooled to some level for some specific duration; a few days after removal, seedlings were assessed for damage using various criteria, including odour, general visual appearance, and examination of cambial tissue.
Stock for fall planting must be properly hardened-off. Conifer seedlings are considered to be hardened off when the terminal buds have formed and the stem and root tissues have ceased growth. Other characteristics that in some species indicate dormancy are color and stiffness of the needles, but these are not apparent in white spruce.
Forest tree nurseries
Whether in the forest or in the nursery, seedling growth is fundamentally influenced by soil fertility, but nursery soil fertility is readily amenable to amelioration, much more so than is forest soil.Nitrogen, phosphorus, and potassium are regularly supplied as fertilizers, and calcium and magnesium are supplied occasionally. Applications of fertilizer nitrogen do not build up in the soil to develop any appreciable storehouse of available nitrogen for future crops. Phosphorus and potassium, however, can be accumulated as a storehouse available for extended periods.
Fertilization permits seedling growth to continue longer through the growing season than unfertilized stock; fertilized white spruce attained twice the height of unfertilized. High fertility in the rooting medium favours shoot growth over root growth, and can produce top-heavy seedlings ill-suited to the rigors of the outplant site. Nutrients in oversupply can reduce growth or the uptake of other nutrients. As well, an excess of nutrient ions can prolong or weaken growth to interfere with the necessary development of dormancy and hardening of tissues in time to withstand winter weather.
Stock types, sizes and lots
Nursery stock size typically follows the normal curve when lifted for planting stock. The runts at the lower end of the scale are usually culled to an arbitrary limit, but, especially among bareroot stock, the range in size is commonly considerable. Dobbs and McMinn examined how the performance of 2+0 bareroot white spruce related to differences in initial size of planting stock. The stock was regraded into large, medium, and small fractions according to fresh weight. The small fraction had barely one-quarter of the dry matter mass of the large fraction at the time of outplanting. Ten years later, in the blade-scarified site, seedlings of the large fraction had almost 50% greater stem volume than had seedlings of the small fraction. Without site preparation, large stock were more than twice the size of small stock after 10 years.Similar results were obtained with regraded 2+1 transplants sampled to determine root growth capacity. The large stock had higher RGC as well as greater mass than the small stock fraction.
The value of large size at the time of planting is especially apparent when outplants face strong competition from other vegetation, although high initial mass does not guarantee success. That the growth potential of planting stock depends on much more than size seems clear from the indifferent success of the transplanting of small 2+0 seedlings for use as 2+1 "reclaim" transplants. The size of bareroot white spruce seedlings and transplants also had a major influence on field performance.
The field performance among various stock types in Ontario plantations was examined by Paterson and Hutchison : the white spruce stock types were 2+0, 1.5+0.5, 1.5+1.5, and 3+0. The nursery stock was grown at Midhurst Forest Tree Nursery, and carefully handled through lifting on 3 lift dates, packing, and hot-planting into cultivated weed-free loam. After 7 years, overall survival was 97%, with no significant differences in survival among stock types. The 1.5+1.5 stock with a mean height of 234 cm was significantly taller by 18% to 25% than the other stock types. The 1.5+1.5 stock also had significantly greater dbh than the other stock types by 30–43%. The best stock type was 57 cm taller and 1 cm greater in dbh than the poorest. Lifting date had no significant effect on growth or survival.
High elevation sites in British Columbia's southern mountains are characterized by a short growing season, low air and soil temperatures, severe winters, and deep snow. The survival and growth of Engelmann spruce and subalpine fir outplanted in 3 silvicultural trials on such sites in gaps of various sizes were compared by Lajzerowicz et al.. Survival after 5 or 6 years decreased with smaller gaps. Height and diameter also decreased with decreasing size of gap; mean heights were 50 cm to 78 cm after 6 years, in line with height expectations for Engelmann spruce in a high-elevation planting study in southeastern British Columbia. In the larger gaps, height increment by year 6 was ranging from 10 cm to 20 cm. Lajzerrowicz et al. Concluded that plantings of conifers in clearcuts at high elevations in the southern mountains of British Columbia are likely to be successful, even close to timberline; and group selection silvicultural systems based on gaps 0.1 ha or larger are also likely to succeed. Gaps smaller than 0.1 ha do not provide suitable conditions for obtaining adequate survival or for growth of outplanted conifers.