The shell is very hard and consists of two layers which are tightly bonded together. 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 seed coat 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.
The primary tool is a pair of pliers, which has the usual pipe grip cut out 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 using sand paper to wear away part of the seed coat. 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 colour. 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 coloured area coming into view in the centre. If you stop here you will still have satisfactorily rubbed the seed. If the area suddenly brightens into a clear cream colour 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.
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 20C and 30C. Change the water daily you will soon see 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.
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 in-rolled first leaf after it. At this stage of growth the seedling looks like a sharply bent fish hook with the in-rolled 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.
As 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 in-rolled 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 centre 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.
Now that most of your Nelumbo seedlings have produced their first floating leaves, what next? These leaves are remarkably suited for a floating existence. The leaves refuse to allow water to remain on its surface. Water rolls off like quick silver. Nevertheless, this surface invites many aphids, which appear almost miraculously even though the pond has not seen them before.
After the first four floating leaves are formed, the plant spreads by forming rhizomes with one leaf appearing at each internode. Side shoots occasionally appear at the internodes, which allow for lateral spreading. The leaf diameters progressively increase and eventually are lifted clear of the water surface. In some instances during the first year of growth, the plant may pass through a temporary resting period. In these cases, growth ceases, the leaves turn yellow and the plant appears to be dying. This is a perfectly normal development for these plants during which the rhizome thickens to form a small banana shaped tuber. The plant then remains dormant for about three weeks when it starts growth again with renewed vigour if the water is warm.
During the first year of growth, only leaves are produced in most cases. Flowers are not generally produced until the second year. As the days get shorter in autumn, the leading rhizomes grow deep underground and form large resting tubers where they wait out the winter. All the leaves turn brown and only the resting tubers remains alive to start growth again the next spring.
