Some species of bananas can be multiplied by seeds.
This is not the fastest nor easiest way because germination is often erratic:
- the number of seeds that eventually germinate varies considerably
- germination may last from a few weeks to 1 year
But many plant enthusiasts like sowing because it gives a lot of satisfaction.
Sowing has some advantages compared to the purchase of banana plants:
- the seeds are much cheaper than plants (10 seeds for about $ 2.50 instead of € 25 for a plant)
- it is easy to obtain seeds from all over the world through the internet
- banana plants generally grow fast and it is possible to have a nice sized plant in one growing season
- some species can even flower and come to fruition in a single growing season
I give you some general guidelines that apply to most types of bananas, Musa as well as Ensete.
Banana seeds usually germinate easily immediately after maturity of the fruit.
Then the seeds go into dormancy: they dry out and only germinate when conditions are favourable for germination.
2. What causes the germination of banana seeds?
The two main factors that lead banana seeds to germinate are water and temperature.
During dormancy, the seed dries out. When water is available, the seed is wetted by imbibition: it absorbs water through apertures in the seed coat or through the micropyle closed by the operculum or micropylar plug.
Tests with imbibing fresh and less fresh (and thus dried) seeds show that for less fresh seed imbibition is greater. This is probably because the micropyle has widened due to dehydration.
But ultimately it makes little difference: in both cases, banana seeds can absorb enough water to germinate.
Note: scientific studies show that the maximum imbibition is generally achieved after 24 hours. It is therefore not necessary to soak the seeds 2-3 days because it does not make much difference in the amount of water absorbed by the seed. It is important to use lukewarm water, for example in a propagator with heating or by placing the soaking seeds in a warm place.
Temperature and temperature variations:
Most banana seeds need a temperature between 20 and 35 °C to germinate.
Ensete prefers a constant temperature, the same temperature day and night. You can achieve that with a heated propagator or by placing the planted seeds in a warm place.
Many Musa species , however, prefer a temperature fluctuation. For example 18h at room temperature (15-20 °C) and 6 h with heating (25-30 °C).
The Musa seeds germinate faster if you provide with a fluctuating temperature than at constant temperature.
It is especially important that the substrate be sterile.
Other than that, the type of substrate has little significance. It only serves to provide sufficient moisture and mechanical support to the seed.
If you use potting soil, it must be sterilized in the microwave oven. Careful, it’s very hot, so do not handle with bare hands to prevent burns and let it cool before planting the seeds to avoid cooking them.
You can also use any inert (or nearly inert) substrate:
- kitchen paper
- cotton wool
- coco peat
You can of course put the seeds in an ordinary plant pot. Personally, I do not like it because you have to constantly check if the substrate is wet enough.
And when you have seeds that take months to germinate, you may forget them and let the substrate dry out.
Seeds that were moistened then dry usually die: the germination process is stopped and the embryo does not survive.
Therefore I always sow in an airtight jar: Tupperware, a small recycled plastic pot, a jar, a soda bottle cut in half to make a mini greenhouse… it does not need to be big because once the seeds germinate, they can be replanted in a bigger individual pot.
You can also sow in a plastic bag, for example a zip lock bag that can be closed.
Don’t seeds need oxygen? Yes, but in trace amounts.
You can safely leave the seeds a few months in a closed container. They will germinate and even grow. It is the principle of a terrarium.
Some plants need light to germinate. However, for most banana species, the presence or absence of light has no effect on the germination.
Some species of bananas need light, for example Musa velutina. Light seems to promote germination but even without light, they will eventually germinate, it only seems to last a little longer.
7. Scarification of seeds:
Scarification of seeds is mechanically or chemically damaging the hard coat of a seed so that water can be absorbed more easily.
In principle, it is not necessary for banana seeds: enough water can be absorbed through the micropyle closed by the operculum or micropylar plug.
For some recalcitrant seeds, scarification, however, can help.
The easiest way is to wedge the seed in a vise or clamp and to sand it with a file until the white endocarp becomes visible.