Chapter 2: Site Selection
Ginseng will grow under a wide diversity of climatic conditions, as well as site parameters in the Pacific Northwest. None-the-less, every effort should be made to consider the physical and chemical properties of the land being considered as a potential ginseng garden. The ultimate root yield and quality will be very much dependent upon the care in selection, and the degree of preparation.

Physical attributes
Most of the cultivated ginseng gardens established in the Northwest over the last 8 years have been on level or gently sloping terrain. A site with a slight slope, on the order of 1-5 %, will ultimately be the easiest to work with over the 4-year life of the planting.

Figure 1 is a garden with a gentle slope. As ginseng gardens do not have vegetative cover crops between the rows, the potential for soil erosion increases in direct proportion with the soil slope. A slight slope will help drain cold air from the planting as long as there is not a large, imperious grove of vegetation at the base of the field. Slopes of more than 10% are generally not suitable for artificially cultivated ginseng.

Shade panels and rain
Slope is a consideration as it relates to water running across the shade netting suspended above the ginseng garden. In the early spring the shade panels are pulled over the supporting posts and wires in order to protect the newly emerging ginseng from the sun. Spring rains will gently fall through the shade cloth. As the soil slope increases however, towards 5%, rainwater will run across the netting. If the shade netting is not firmly stretched, water running over the top of the nettingg will suddenly pour through the slack areas. The large volume of water which cascades to the ground beneath has been found to not only wash away some of the ginseng plants (see Figure 2), but will also encourage root rot in these areas. Each spring growers will need to check their post and cable support structure to ensure even tension on their shade panels.

Growers who plan to use the woods-grown technique, will find that soil slope is not as crucial as for field cultivation. As for wild-simulated ginseng, slope is of even less importance, other than for the inconvenience of having to expend more energy climbing steeper hills!

Air flow
It is best to select a site that is exposed to plenty of air movement, especially on the west sides of the Cascades. With cultivated ginseng the rows should be oriented parallel with the prevailing winds to speed foliage drying during the spring when leaf blight (Botrytis sp., see Chapter 11: Disease Overview) is the principal threat to the developing foliage. With cultivated ginseng, where the plot has been started by scattering seeds, the resulting dense foliage can lead to significant leaf blight. Dense hardwood and softwood trees surrounding the proposed ginseng garden may have to be thinned to ensure air movement. With woods-cultivated ginseng, large trees generally can not be removed, as they are needed for shade.

Windy sites
Sites that tend to be excessively windy (more than 15 mph) can be challenging upon which to grow ginseng. After the beds have been seeded, excessive wind can blow the sawdust mulch off the beds. A windbreak of trees may need to be planted to break the wind. If poplars are used for a windbreak be sure to plant them far away from the garden so that their extensive roots don't become a problem. Excessive wind can also get under the shade panels and can lift the support structure. Chapter 6: Shade requirements will discuss the options for keeping the support system intact.

Slope direction
Slope direction is generally not all that important in ginseng cultivation. A gently sloping south facing slope will warm up the fasted in the spring, though heat stress may be more of a problem during the summer. North facing slopes are cooler and moister, which may lead to a greater incidence of root rot, damping off, and leaf blight.

Soil drainage
The very best ginseng site will consist of a loam topsoil, fight in texture, which is well-drained. Organic matter should on the order of 3-5%. In eastern North America wild ginseng is found naturally where the soils are rich, beneath the abundant leaf litter broadleaf deciduous trees such as oak, beech, and hickory. A loam soil, with less than 20% clay, will offer the optimum soil drainage, as well as ensure good moisture retention during the hot summer months.

In areas west of the Cascades, a soil heavy in clay particles can be very deleterious to longevity of the ginseng garden as the heavy winter soil moisture retention leads to root rot. Conversely, sandy soils, low in organic matter, are generally more difficult to manage as they tend to be drought prone. Smaller garden sites can be amended with organic materials such as compost, well-aged animal manures, green manures, or even aged yard debris. Incorporation of soil amendments help clay soils drain better, and help moisture retention on sandy soils. Chapter 3: Site Preparation will discuss how to improve the site selected.

Stony sites
Ginseng should not be considered for excessively stony sites. The presence of gravel and stones will impact root growth and hamper harvesting efforts. A modified potato harvester is often used to lift root. Naturally stones and gravel will come to the surface as well..