Straight off the bat I will say that germination of aquatic seeds is not the same as germination of normal plants and vegetables. It is no harder to do, and the greenness of your thumbs is totally irrelevant, but there are rules and methods specific to each of them.
If you don’t give the conditions needed for life, then you will only have death, or at very best “dormancy” which is where the seeds just sit there waiting for weeks, months, or even years for you to give them the conditions that they need.
Nelumbo nucifera seed germination.
This fella is designed to sit dry and dormant for very long times.
Some seeds have even remained viable for more than 1000years, before being uncovered and planted by scientists. They germinated just fine.
They are designed to have this dormancy so that if there is a drought and the pond dries out for a few years or even decades when it eventually fills up again the lotus can all spring into action.
The cue for their germination is damage to the seed coat followed by water penetration which allows germination inhibiting chemicals to be diluted and leach out. Once water gets through the shell then they kick into gear.
I see all sorts of nonsense about snipping the eye or damaging the pointed ends of the seeds and I am happy to admit this works fine, sometimes. The thing is, it often damages the shoot or root too, and sometimes this kills them. I personally want folks to have maximum success and no death…
The only method I use and recommend is to damage the flat side of the seed, NOT the pointed ends where the delicate shoot and root is hidden!
All you do is get a steak knife, a steel file, or even just the corner edge of tile or the concrete gutter.
Rub the side of the seed back and forth on it. You are just making a small lengthways line or cut into it the shell of the seed. This to allow water access. The layers will be exposed as you cut down into it and it goes black, brown, tan and then white. As soon as you can see light brown or tan SLOW DOWN!
As soon as you can see any white STOP!!!
Cutting too deep can cause death by fungal attack, but it is very very rare when you do it this way.
Drop the seed in a bucket or bowl of water and they will be shooting in less than 3weeks.
I get 99.99% successful germination using this method.
Nymphaea caerulea seed germination.
These guys are designed to have a strong dormancy too. The plant flowers, then the flowers close and the pods develop, and as they do this the flower stalk twists forcing the pods deep underwater and into the soft mud below.
Their cue to germinate is a period of dry, followed by a gradual increase in water depth. They won’t ever germinate if they fall from the plant and remain underwater never drying out.
If that happens they assume the mother plants are still thriving so the baby seeds just sit and wait in reserve in case of a drought or dry period.
They won’t ever germinate if they fall from the plant and dry out, then they are placed directly into very deep water. The baby seeds won’t get light and because of this they assume there has been a flood. If they shoot now the water will be way too deep for the leaves to ever reach the surface of the water.
They won’t ever germinate if it is too cold, or if they get confused as to what is happening weather wise.
If you rush any step they will rot and die, or they will freak out get confused and just go back to sleep.
At which point a long period of dry, followed by a long period of rising water levels may recover the seeds and get you some plants, maybe…
All of these issues are due to deliberate survival tactics used to deal with precarious life in a seasonal pond or river.
Too much or too little water is fatal in nature.
The method for germination of these guys is get a heap of small pots. Add soil, mud or clay to the bottom of the pots, and sit the seeds on top. Then sit the pots in a large deep plastic tub or polystyrene vegetable boxes.
Water very very gently with a fine rose watering can.
To start with you want no water or at very maximum a couple millimetres of water pooling in the bottom. In a warm climate like mine this needs to be topped up every 1-4days. After a couple weeks increase this watering and allow to level to VERY SLOWLY creep up the sides of the pot, day by day, week by week.
With a sandy soil like mine germination normally begins when the water eventually reaches just below the seeds. With muddy or clay soils that hold water better this may happen a little early. If there is no change or no shoot then you need to keep waiting. As soon as you see a cracked seed or any green it is vital that from that moment onwards the water remains level with the seeds. If it is cold where you are or you rush any step of this super easy but very slow process you will cause them to go into a heavy dormancy again, meaning you are best off waiting a few months, then drying them all out and starting all over again. If dormancy doesn’t kick back in then you will just kill them by low oxygenation of the water followed by an anaerobic bacterial attack.
Do not add any fertiliser in the soil or water at all EVER!!!!
If you feed the soil or the water the dominant life form will take over and kill them. This is always algae and/or bacteria, not your delicate baby seeds. They are so small that they do not need to eat at this stage.
Slow and steady folks.
Assuming you now have the beginnings of germination they are sending up a shoot increase the water level daily, a millimetre at a time, just until the first leaf begins to unfurl and starts to flatten out.
Now leave it to rest and recover at exactly that depth.
When the next leaf comes out gradually increase the depth again stopping to rest when the plant needs it and that leaf has begun to unfurl.
By the time they are ~30cm below the surface, they will have at least three leaves and most importantly, a nice big plug of healthy roots. At that stage they can be planted out into the walls of dams, water features, fountains, or fish ponds.
It is a good idea to repot them with a large rock in the soil to keep the plant sunk in place where you want it and slightly prevent yabbies messing with the roots.
WARNING ABOUT TRANSPLANTING ALL TYPES OF LOTUS!
Being edible species everything loves to eat them so expect losses when you plant them anywhere that already has any life.
Yabbies, prawns and shrimp love to mess with the roots. They don’t actually eat much, but they sometimes snip all the roots off and send your plants loose. Destructive little buggers!
Tadpoles rasp the algae off the leaves and doing so they damage the plants surface which can cause infection or just stress them.
Some fish like my spangled perch just eat them like a lettuce. Some fish like catfish, carp and koi only target the tender new shoots as they emerge from the mud meaning the plant continually tries to send up a new leaf and fails, and eventually, it exhausts all its energy and dies.
Snails of all forms absolutely hammer them, and moths and butterflies lay eggs on the leaves which later hatch into destructive little caterpillars. They can decimate huge amounts of plants in a very short time.
Native turtles and waterfowl eat them, and domesticated ducks and geese can be especially destructive.
With all of these things having a go at them it may be difficult to establish them where you are in your set of environmental circumstances. For me it came down to critical mass, just a numbers game.
The bigger the plants and the more of them added at once, the greater the odds of success and though it took me a few goes I got there in the end. It’s all a very very simple process, but you do need to provide the conditions they need, you definitely need to have patience.
Like all things botanical a little luck never hurts either…