In 2001, water gardening legend Walter Pagels, San Diego, California, offered Nelumbo seed from his personal collection to members of the IWGS email discussion list who were interested in participating in a germination experiment. The following is the journal/newsletter that Walter provided as the experiment progressed. It also contains excellent descriptions of and tips on germination of seeds and early growth of seedlings.

Nelumbo (Lotus)
Germination & Seedling Growth

By Walter Pagels
Photos by Kit Knotts - Click to enlarge 

Saturday, May 26, 2001
Nelumbo Seeds Offered

For the last 40 years I have been collecting seeds of the two Nelumbo Species [N. lutea and N. nucifera]. As you probably know, Nelumbo seeds remain viable for many years, some estimates give them up to 1000 years; however, they sprout rapidly when put into water after the surface of the seed has been scraped.

I now find that I have more seed than I have space for them to grow; consequently, if there are some of you who would like to try your hand at growing the U S native Nelumbo lutea and/or old world N. nucifera from seed, email me your snailmail address and I will send you some seed with instructions on how to germinate them. You should have several floating leaves within a month. 

Thursday, May 31, 2001
Nelumbo Seed Lots Tabulated

I will shortly send out Nelumbo seeds to all the readers who wrote me a note requesting them. The seeds are very tough, so I am sure they will ship safely in Bubble Mailers. The first batch will go out to addresses that are overseas from the US. They will be sent air mail since the packages are light enough to go economically that way. The seeds will be selected from 14 separate collections and the Lot Number will be on the package. The reason for this is to allow record keeping for determining the relative success of each collection of seed.

These seed had been stored dry in jars for up to 40 years, so they are relatively fresh as far as Nelumbo seeds go. Unfortunately, the stick-on labels are not so hardy, so many dropped off when the stick-on paste dried. The silverfish also made some good meals of these and others that were still attached. Consequently, some collections are now of unknown origin. In a couple of cases, seeds were sent to me from growers or other collectors, so we even have some cultivars in the collections. These are identified if known. In general, if you specifically asked for either Nelumbo lutea or N. nucifera seeds, I will make a special effort to send those that are positively identified at least to the species level. In the case of Nelumbo lutea, most of my collections were made from either Michigan or Florida. Under the assumption that there is some difference in hardiness in the species from these two areas, I will send the Michigan collected seed to those in temperate climates, and the Florida seed to the more tropical areas.

The Lot Numbers and their identification are as follows. Make a record of this list because the mailed packages of seeds will be identified only by Lot Number. Seeds from at least two lots will be sent to each recipient.

1) Nelumbo lutea seeds collected from Michigan in year 2000
2) Nelumbo lutea seeds collected from Michigan in 1985
3) Nelumbo lutea seeds collected from Florida in 1988
4) Nelumbo lutea seeds collected from Florida in 1982
5) Nelumbo cultivar seeds sent to me from Wilson Yeo of Singapore, 1988
6) Nelumbo nucifera, unknown source
7) Nelumbo nucifera, unknown source
8) Nelumbo nucifera, unknown source
9) Nelumbo nucifera, unknown source
10) Nelumbo nucifera, unknown source
11) Nelumbo nucifera, unknown source
12) Nelumbo nucifera, unknown source
13) Nelumbo sp.
14) Nelumbo nucifera cultivar, white flowers

I have already taken a sample of seeds from each lot to check viability. I will send out newsletters periodically to indicate the estimated viability for each lot.

In my original offering letter, I said that I would send growing instructions with the seed; however, I will instead put the instructions out in a letter to the IWGS List so that every one can see them. This has an advantage because other persons who have successfully grown Lotus from seed can now comment on the instructions and possibly suggest alternate methods which have merit.

Wednesday, June 06, 2001
A Lotus Survival Tactic

The seed of the Lotus (Nelumbo sp.) is a very hard nut and is almost completely impermeable to water. It remains viable for many years; some evidence indicates over two hundred years at least. If the seed is placed into an ideal habitat for growth, it may still remain dormant for many decades before sprouting. It seems almost counterintuitive that being resistant to sprouting has a survival advantage.

Researchers who have worked with the plant have theorized on why having seeds that are so difficult to germinate is advantageous to survival. The probable reasons for this survival tactic in the genus Nelumbo are two fold. The first is that when the lotus occupies an area, it spreads rapidly by vegetative means until every suitable site is covered. If a seed sprouts in such an environment, it will have little chance for survival because it will be shaded out. The second reason is that the tubers of the lotus are very nutritious. Humans also find them good food (you can find them as a fresh or canned vegetable in Asian food markets). If any aquatic herbivore (muskrat, beaver) pair happens upon the growing site, it will establish a home there and raise a family of several generations until the entire stand is devoured. If the surviving dormant seeds then proceed immediately to germinate, the succeeding generation would also be eaten. Consequently, until the herbivores move out for lack of food, it is best for the seeds to remain dormant for a while.

I had personally observed one such cycle in the waters of western Lake Erie. During the 1930s and early 1940s I used to visit these stands of Lotus which at that time covered hundreds of acres. These Lotus beds were even an advertising feature of the local towns to attract tourists. The start of the second World War and my resultant departure from the area caused me to cease these visits. I did not return to the marshes until 1952. Not a single Lotus could be found. When I queried the local residents in the area about this disappearance, they said that the Lotus were eaten by muskrats after Michigan put them under game protection. Nevertheless, I would still periodically revisit the areas to see if the lotus had returned. I finally gave up my visits by the mid 1960s. Then, in 1976, I read a newspaper article that said that sightings of Lotus in the marshes had been reported and was given endangered status. With binoculars in hand, I was able to make out the beginnings of a few Lotus colonies. Passersby would ask me what birds I was looking for. When I told them I was looking for Lotus plants, they shook their heads and could not understand what I was talking about. The memory of the former expanses of Lotus blossoms had been lost.

Since then, many of the former Lotus beds have returned. You can even see them from your automobile when traveling on Interstate 75 between Toledo, Ohio and Monroe, Michigan. For a closer look, the Michigan Nature Association has established the "American Lotus Plant Preserve" in the Swan Creek estuary which can be reached from I-75 by taking Exit 21.

Thursday, June 07, 2001
Nelumbo Seed News

I hear that some Nelumbo seeds have already arrived at their destinations. It seems that everyone in the US and some overseas destinations should get their seeds by this weekend. So that everyone gets an equal start on sprouting the seeds, I hope that those who get their seeds earlier will hold off starting them until then. With this in mind, I will email my sprouting method to everyone on Friday so that everyone can start their sprouting on Saturday.

This should be a happy experiment. We will be testing the success of growing Lotus from seed under a variety of conditions. So far there are 69 participants in this experiment including myself. Everyone should have gotten at least two different lots of 7 seeds each (unless I messed up in packaging). If anyone comes up short, let me know. I have kept a sampling of seeds from each seed source so as to determine the relative viability of each lot. I will prepare these sample seeds for germination on Saturday.

As this experiment progresses, send any inquiries or news to me directly so as not to overload the IWGS mail list about this one subject. I will periodically send a newsletter to all Nelumbo growers via the mail list.

A few of you will be receiving your seed after the start date because of distance or late request. Indeed, those of you down under may want to delay starting the seed until later because of the reversal of seasons. Whatever the reason, you will have the benefit of learning from the trials of those who went before you.


Friday, June 08, 2001
Preparing Nelumbo Seeds for Germination

 
Pointed end
Nelumbo seeds are nuts which are either round and the size of a green pea or oval and the size of a shelled peanut. One end of the seed has a sharp point which is the remains of the floral stigma. On the opposite end is a tiny dimple, a remnant of where the seed was attached to the mother plant The seed color can vary from gray to dark brown or black. The shell is very hard and consists of two layers which are tightly bonded together. Inside the shell are two paper thin brown colored seed coats which enclose the twin cream colored cotyledons. This feature is what places the Nelumbo genus into the Dicotyledon subclass of flowering plants (Angiosperms). Between the cotyledons is the Nelumbo embryo which consists of two prominent inrolled leaves with attendant stem. The leaves are doubled over against the stems because of the tight space. When the seed sprouts, the stems elongate to push the inrolled leaves up to the water surface. On the way up, the doubled over leaves straighten up and unroll after they reach the surface. There they become the round water-repellent floating leaves which are so characteristic of the Nelumbos. There are no intermediate underwater leaves that are typical for the waterlily family (Nymphaeaceae). This is one of the many reasons for the recent assignment of the Nelumbo genus into its own separate family, the Nelumbonaceae

 
Dimpled end


Click image to enlarge

The inherent characteristic of the Nelumbo seed is to remain dormant for many years even if the environment is perfect for them. This resistance to germination is caused by the seedcoat which is almost impermeable to water penetration. The secret for speeding up the germination process is to remove this protective cover without harming the internal seed. Many methods of doing this have been described in the literature (including soaking in concentrated sulfuric acid for 5 hours), but the method I use is easily available to every one. The primary tool is a pair of pliers which has the usual pipe grip cutout at the business end. The pliers are used to get a firm grip on the seed within the oval pipe grip section of the pliers. The seed is very tough and you do not have to grip the seed so hard as to crack it. The seed is then rubbed along a rough surface to wear away part of the seed coat. The preferred surface is a medium grit sand paper laid flat on a table, although a concrete surface or file can be used. The optimum grit size for the sandpaper is # 80, although a finer grit (higher number) can also do the job. It just takes more rubbing and the sandpaper wears out sooner. You will then appreciate how hard the seedcoat really is.

There are two areas where the seed scouring can take place: on the side or at the dimpled end. I prefer the side because the progress of the rubbing (or sanding) is more uniformly determined. When scouring the side, rub the seed in one area only. This will produce a shiny flat surface as the rubbing proceeds. This surface should be inspected frequently to check the process of the wearing away process. At first, the surface is a uniform black color. As the rubbing proceeds, a thin white line circle or oval will appear, depending on the seed type. This indicates the breaking through of the junction between the two fused seed coats. At this point you can stop the rubbing. If you have missed this point in the rubbing process (it is sometimes difficult to see), and you continue on rubbing, you will eventually see a cream colored area coming into view in the center. If you stop here you will still have satisfactorily rubbed the seed. If the area suddenly brightens into a clear cream color with a distinct edge, it means you have broken into the cotyledon. This opens the seed to possible fungal infection. But save the seed anyhow, it may survive.

If you rub, file or sand the dimpled end, the sequential events are not so clear cut as described above because the seed structure is not as uniform. In fact, there is an irregular airspace between the seed shell and the cotyledon and you may break into it before the cotyledon is reached. This is an acceptable result for seed preparation, but not consistently attainable. Those of you who have an adventurous nature may want to attempt this route. As a further comment, this is the seed end where the seedling emerges from the shell.

After the above preparation, the seed is placed into a container of water. I find clear plastic cups work out well. Place the cups with the seeds in a warm place where the water will remain between 70 and 90 F. Temporary movements outside this range will do no harm; however, the cooled temperatures will delay the sprouting and growth rate of the seedling.

The first thing you will notice after a few hours is a change in the color of the water: it will either turn a clear tan color or cloudy white. The cloudy color is caused by bacteria feeding on the exudation from the seed. If the water is not replaced, a thin scum will form on the water surface. The rapidity at which this occurs depends upon the container size; the greater the water volume, the less the effect. Nevertheless, the water should be changed and container walls scrubbed to keep the environment reasonably clean. I have not seen where slightly cloudy water harms healthy seeds, but I haven't tested the limits. When the water starts out with a clear tan color, it seems to suppress the bacterial influx.

The second thing you will notice is the swelling of the seed to almost double in volume. In some cases the seed coat will exhibit irregular bulges; this is normal. The seed coat becomes soft and has the texture of leather. This process usually occurs within a day or two, but for some seed it may take up to a week. This expansion is produced by the cotyledons as they take up water. In a few cases, the seed may float to the surface of the water.

After the swelling is completed, there will be a period of no activity as the seed thinks about whether or not to burst out from its shell. This can happen anywhere from one day to several weeks. One of the purposes of this group experiment is to gather some statistical data on the sprouting periods of various lots of seed. When a seed does sprout, the seed coat splits longitudinally, starting from the dimple end. The two cotyledons then separate as if on a hinge at the pointed end of the seed. The folded-over stem of the green embryo can then be seen between them. The folded stem grows out of the seed shell and pulls the inrolled first leaf after it.  


Sunday, June 10, 2001
Nelumbo Growing Project has Started

I believe most of you who have received the species Lotus seed have now prepared the seed for germination and placed them in a container of water on Saturday. In a very short time you should see them grow in size as they absorb water. It is then only a matter of time until the seed embryo starts to grow. As is characteristic with wild plants, these seeds will not all germinate at the same time. Our domesticated flower and vegetable seed have been conditioned over many generations to sprout on command, so to speak. But when plants have to exist in the uncertain world that Mother Nature provides, the wild plants need to keep some seeds dormant in reserve in case the first sprouts face unfavorable growing conditions.

I have also prepared a few seeds for germination from each seed lot to allow me to compare my results with yours.

Monday, June 11, 2001
First day results of seed sowing

The day after you put the seeds in a container of water, you should notice that your seeds have increased in size. This is due to the intake of water which hydrates the dried cotyledons and dormant embryo within the seed coat. In a few cases, some of the seeds will begin to float. These seeds will sprout just as readily as the ones that remain under water. You will also observe a slight change in the color of the water in your seed container, either to a light tan or a cloudy white, the intensity being related to the amount of water in the container. The tan color comes from the tannin in the seed, the cloudiness from bacteria feeding on the other exudation from the seed interior. I have never seen any harm done to healthy seeds by this, but if the water is not changed periodically, the color or cloudiness can become so intense as to obscure the seeds from view.

If everything goes according to schedule, some of the seeds should begin sprouting within a few days. The minimum temperature for this to happen is approximately 60 F. Temperatures up to 85 F speed up the process. The start of the sprouting is determined by the gradual splitting of the seed coat starting at the dimple end. In general, the Nelumbo lutea seed takes twice as long to sprout as the Nelumbo nucifera seed under similar conditions.

Tuesday, June 12, 2001
Second Day Results of Nelumbo Seed Sowing

Needless to say, nothing startling has happened here on the second day after putting the seeds in water, aside from the fact that some of the cups of water had to be changed. However, Jim and Sharyn Munn had started their experiment a day early (Friday) so their effective third day report is that 5 of the 7 seeds from Lot 7 had sprouted, and 1 seed out of 7 seeds from Lot 9 had sprouted. So the rest of you who have Nelumbo nucifera seed should be seeing some good results today. The Nelumbo lutea seeds should be following a few days later.

Wednesday, June 13, 2001
Third Day results of Nelumbo Seed Sowing

All seeds have now approximately doubled in size, and a few are floating. Splits in some of the seeds in lots 6 and 7 were found, which means that sprouting is imminent. As usual, the water in about half of the seed cups needed to be changed. Everything is normal.


 
Day 1


Day 2


Day 3

Wednesday, June 13, 2001
Raising Nelumbo Seedlings

When the Nelumbo seed sprouts, the two cotyledons separate as if on a hinge at the dimpled end of the seed. The folded over stem of the green embryo can then be seen between them. The folded stem grows out of the seed shell and pulls the inrolled first leaf after it. At this stage of growth the seedling looks like a sharply bent fish hook with the inrolled leaves imitating the barb. The fish hook bend in the leaf stem slowly straightens out while the stem continues to grow until it is at least eight to fifteen inches long. Consequently, because the stem is fairly stiff, the leaf may be pushed out of the water if the depth is less than eight inches. With a moderate water depth, the leaf stem will start to bend over and push the leaf horizontally just beneath the surface. For deeper water the stem will continue to grow vertically until the leaf reaches the surface. At that point, the inrolled leaf begins to grow and expand until it floats flat on the water. The leaf diameter will be between one and two inches. The period of time to reach this stage is about ten days after sprouting. After the leaf has unfurled, the stem does not readily accommodate water level changes, so if you intend to transplant the lotus later into a pond, the new water depth should be similar.

The seedling can be planted or potted at this stage, but since the roots have generally not yet formed, it isn't necessary. Nevertheless, one should keep an eye on the unplanted seedling for root inauguration. Planting the seedling before or at the beginning of root growth prevents subsequent root damage. The seed contains enough food to sustain itself without extra nutrition until after the first four floating leaves have formed, about 30 days after the seed has sprouted.

 If the seedling is to be potted before being set out into its final location, the pot should have a surface diameter of at least eight inches. The height need not be more than about five inches; however, anything larger is always beneficial. The reason for this is that while the first four leaves are forming, the Nelumbo starts developing a rhizome which needs to run several inches before the next leaves are formed. If the edge of the container is reached before this happens, the growth of the plant can be distorted. If the rhizome is not deflected to the right or left (which is often the case), the rhizome growth will push the plant center out of the soil. If the rhizome is deflected to the right or left, the growth will circle the container if it is round. If square, the potential for uprooting will repeat at every corner.

I have found that the preferred potting soil for Nelumbo seedlings is heavy loam; however, I encourage experimenting with different soils if you have multiple seedlings.

After the first leaf has unfurled, or a bit earlier, the second, third and fourth leaves come to the surface in orderly sequence. All these leaves come from a common node next to the seed. While these leaves are coming up, the plant starts to send out the horizontal rhizome from which the fifth and subsequent leaves will grow.

To be continued



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