Chapter 9: Seed harvest and propagation

It is important to review the steps required to overcome the inherent dormancy characteristics of North American ginseng as nearly all cultivated ginseng gardens, as well as a good percentage of woods grown gardens, are started from seed.

New growers
New growers generally purchase what is known as 'stratified seed' usually from a neighboring grower who has more than is needed. There is nothing wrong with ordering stratified seed from other growing regions other than for the additional expense. At the present time stratified seed is selling for approximately $40/pound (refer to Chapter 18: Enterprise budget). Established growers can look upon seed sales as an additional revenue generator. The price will vary each year depending on supply and demand. When planted in the fall, stratified seed will germinate 6 months later, usually during the first of April in areas west of the Cascades.

Starting with green seed
Non-stratified seed, also commonly referred to as 'green seed', can be considered as a planting source though the time and effort in planting this type of seed in prepared beds is really impractical. There will be an 18-month delay before the seeds germinate after removal from the red fleshy berry that surrounds the seeds. Though green seed will be less expensive than stratified seed (50% less expensive), losses due to diseases are often higher. Most new growers want to get into production as soon as possible, and are thus not interested in planting green seed. Weed growth during the 18-month waiting period will be excessive. Green seed that has started to germinate prematurely in stratification boxes after 6 months is another source of seed, but planting these seeds is complicated by the wet winter weather the Pacific Northwest is famous for.

New growers will find their plants producing seed in earnest after 3 years and will have to learn how to stratify seed for future plantings. Occasionally, two-year old plants will set a few flowers. Most growers remove these as they appear in order to funnel more of the young plants energy into the root system.

Flowering
Ginseng plants two years and older will start to form a flower structure known botanically as an inflorescence (technically an umbel) in early June (see Figure 1). Each umbel has as many as 50 flowers. As each flower opens the female stigma and male stamens are soon visible. While bees and flies can be seen hovering near the flowers, they are not required for pollination to occur. Ginseng flowers are self-fertile. With this open pollinated crop there are no concerns over the source of pollen. The seeds that eventually develop from the flowers thus will exhibit the great variability of a genetically unimproved species. Flowering begins in the Northwest by mid-June.

Flower removal
At first thought why would anyone want to remove flowers? There have been reports in the literature concerning root harvest in year 4 may benefit from lack of flowers. Recent work in Ontario has found that flower removal in year 3 and 4, so that no fruit (druplets with berries inside) are allowed to form, has increased yield by 55% in experimental plots at harvest time. Removal of flowers only in year 4 also increased root yield, but only 34% over the controls where flowers were allowed to continue their development. Some growers may choose to allow only a percentage of the flowers to form berries in year 3 and 4. This will increase root harvest significantly, though at the expense of seed production. Most new producers are more interested in growing their own seed to further expand their ginseng acreage and thus will probably keep all the flowers that form.

Seed formation and collection
After flowering, green berries, botanically known as drupes, begin to form where flower petals once existed. Druplet formation continues over a period of time. By mid-August the first tinges of red develop in the druplets. The collection of druplets ripens from the base upwards. Generally it's best to wait until all of the berries have turned from a bright red to a deep dull red before harvesting them. There may be a few that fall prematurely. If time permits, two harvests can be done to ensure all the berries are harvested.

Once collected, the red pulp has to be removed. The easiest method is to simply place the berries into porous mesh bags, and lay them on a shaded concrete surface (see Figure 2). Wet the bags down daily and periodically and lightly step on them to loosen the pulp over a 5 to 10 day period. The natural fermentation process helps. The larger ginseng industries in British Columbia, Ontario, and Wisconsin have de-pulping machines that resemble large revolving porous drums that help expedite pulp removal. It is important to remove all traces of the pulp to reduce the chance it might introduce decay organisms in the stratification boxes. For smaller operations lay the seeds on 1/8" screening to wash of the last remaining pieces of pulp. To date no one has found an economical use for the pulp.

Seed numbers
The ratio of red berries to seed is 4.5 to 1.0. Within each red berry, two seeds reside. Growers may find one pound consists of 6,000 to 7,500 seeds (if they care to count!) from plants grown in more northern gardens, with 8,500 seeds/pound from more southern latitude gardens. Once again however, as ginseng is an open pollinated crop, the source of the seed will have little effect on eventual stand establishment.

After the seed has been cleaned up it should be immersed into a bucket of water. This so called "water test" exposes "floaters" that should be skimmed off and discarded. The good seed that remains should be air dried briefly in a shaded location before it is put in the stratification boxes.

Seed dormancy and stratification
North American ginseng is somewhat unique in that it requires a lengthy time period to overcome internal seed dormancy. If red berries were pushed into the soil the seeds inside (2 per drupe) would not germinate for 18-22 months. To simulate the conditions in the forest that help overcome dormancy, growers have found that they can mix their seed with damp sand in wooden boxes which are then buried in the ground or are covered with more sand. The regime of cool-warm-cool mimics the native ginseng stand that goes through a winter-summer-winter before it germinates. Sand is so much easier to work with than soil. It's cleaner to begin with and can be reused later.

Sand boxes
Growers will use pressure treated fir 2" by 10" lumber to build boxes 4' long by 2' wide (see Figure 3). The bottom of the box should have hardware cloth stapled to the base so that the sand and seed mixture contained within will allow free access to soil moisture. The screen also helps keep out mice. Mix equal parts by volume or de-pulped seed and builders sand. Fine sand is not preferred as it impedes oxygen supply to the seeds. can not be allowed to dry out. Make sure that the boxes are set into ground that will not flood during the winter rain. Growers in areas with roaming cats may wish to place a wire fence around the sandboxes for obvious reasons!

Filling boxes
Don't start filling the boxes until the soil temperature is below 60 F. If there will be a delay in filling the boxes, de-pulped seed should be placed in a plastic bag in a refrigerator. Start out filling the boxes with a 3-4" layer of sand in the base of each box and then layer in seed with sand. The box dimensions described above will hold approximately 100 lbs. of green seed. When finished, the box should be approximately 2" below the surrounding soil level. Place a wooden frame over the top of each box, once again with screening stapled on top. More sand should be spread over the boxes so that the sand in the boxes never dries out.

Woods grown stratification
Wild ginseng in Appalachia will go through a natural stratification process if the seeds are lightly covered with a layer of leaf mulch. The early American pioneers soon discovered that the red berries should be pushed into the soil surrounding the existing ginseng plants in order for new plants to be grown. None-the-less, the percentage of berries that ever produce viable plants in the wild is extremely low. Depredation by rodents, losses due to fungal organisms, and the simple fact that some of the seeds dry out, all contribute to low germination rates. Landowners who have dense woods can purchase green seed, scatter it in their woods, cover it lightly, and wait to see how forgiving nature may be!

Preparing for seeding
After 12 months in the stratification boxes, ginseng seed has gone through a cool/warm (winter/summer) cycle and is thus ready for planting and one more cool (winter) regime. After the sandboxes have been unearthed, the sand should be washed out and the seeds given one more water test to reveal any floaters (see Figure 4). At this time the viable seed (see Figure 5) will have turned a range of colors from an off-white to rich dark brown color. Some of the seeds will have started to split open and small white root tendril may be evident. This is normal and it indicates that the seed (oft

At this point some growers like to treat the seed with a dusting of a fungicide. Apron 50WP is registered for this purpose (see Chapter 12: Foliar, Seedling, and Root Diseases). The fungicide treatment helps protect the seeds once they are planted. Don't wash the fungicide off the seeds, and once again don't let them dry out. If there will be a 2-3 day delay in spreading seeds onto prepared beds, seed should be stored in a plastic bag in a refrigerator.