[jules (OP)]

I recently returned from my first visit to the tropics, and saw many coconuts germinating on the sandy, salty, beaches, only metres away from the ocean. I now want to germinate a shop-bought coconut because I like a challenge, haven't done it before, and while most websites say it is impossible as the outer husk has been removed, some say it can be done. I have soaked my coconut in warm fresh water, it wanted to float with the three "eyes" uppermost, so there must be air inside. After a while it sinks. Eventually one of the three "eyes" should push out a small root if kept warm and humid.
My question is how does a coconut seed (Cocos nucifera) "know" it is not floating around in a salty (osmotically poisonous) environment, and take in fresh water? What stops the seed from germinating while it is floating for weeks or months in the ocean? Surely even on a sandy tropical beach near the tide line it is still salty. Does the hard endosperm have a salt sensor? A "movement sensor" to indicate it has stopped floating, a "gravity sensor" to show it is no longer pointy end up?
I would like to hear from anyone who has successfully germinated a coconut seed, how long it took and what happened.

[RD]

What stops the seed from germinating while it is floating for weeks or months in the ocean?

A coconut on the beach will be warmer than one floating in the sea ...

Seeds often have a temperature range within which they will germinate, and they will not do so above or below this range.

https://en.wikipedia.org/wiki/Germination#Factors_affecting_germination

[Don_1]

Coconuts may not germinate if they have been transported and/or stored at too low temperatures.

How does the coconut know its not floating any more? When floating in the sea, the milk will be moving around. If on dry land or once washed ashore, the milk will stop moving. Perhaps it is the movement of the milk on and off the functional pore which dictates whether to germinate or not.

Also, as RD suggested, the sea temperature will be considerably lower than the land temperature.

The best chance of getting a shop bought coconut to germinate is to buy one still in its husk, sometimes known as a 'green coconut' or 'coconut verde'.

You do not give your location. Let me tell you that unless you live in the tropics (which I think it safe to assume, you don't), you might find it difficult to get a coconut to germinate, even if it is a viable seed and should you have success in this, keeping it alive will also present problems.

You will need to keep it in full sun at daytime temps of around 90^oF and no lower than 70^oF overnight. Humidity must be very high. You will need a good quality very easy draining seed & cutting compost.

Only one of the three eyes is the functional pore, the other two are blind. Put your coconut husk on a flat level surface and roll it a few times. Mark which is 'up' each time. The way the husk comes to rest naturally is the way to plant it. Use a large pot of around 25 - 30cms, use plenty of drainage material at the bottom, then put in your compost and firm it down leaving enough room to put the husk on the compost and tip in more compost to around half way covering the husk. Water well and do so daily. Also mist the husk two or three times a day. Keep the pot on a bed of wet gravel, but do not allow the pot to stand in water. Germination may begin to become evident in a month or two, but can take up to 6 months.

[jules (OP)]

I am in the UK, not quite tropical! Stores only have the dehusked coconut and I have no idea how long they have been kept, or if chilling had been used. They come from Ivory Coast. When I soaked a coconut in warm water for a day, it floated, then sank, so I assume that fresh water has been absorbed. Small bubbles came from the woody shell. I could have tried salty water to see what happened. After a few days, one of the 3 eyes seems more prominent - convex rather than concave - so I think this is the one where the root will emerge. I have the coconut in an insulated container, with a little water, kept at an average of 30C (2C hysteresis) on a heated propagator tray. It does not go lower than 28C, to mimic tropical conditions. I will keep you updated.

[jules (OP)]

It's growing! After 4 weeks in a propagator at 30C, a white root has pushed out from one of the "eyes". Now about 1cm long and 0.5cm diam. Not sure what happens next.....any ideas?

[Bored chemist]

Well, it seems that some people have had some success growing them as pot-plants.

[cheryl j]

Good luck with your project. Post a picture sometime!

[Don_1]

So, you have got your coconut to sprout, well done.

Now you come to the hard part. The UK is never like the Pacific islands and rim where these trees grow naturally. (You don't say!) But at this time of year, you really will have to make an almighty effort to give your palm conditions which will be suitable.

Heat, light & humidity will be the essentials. You will need a large pot of 12" dia, and a deep pot saucer. Use an ordinary bell shaped pot (nothing fancy) so you can pot on later without disturbing the root ball.  Line the bottom of the pot with plenty of good drainage material (broken crock or pea gravel). Now put in and firm down a good, very well draining compost. I would suggest John Innes No. 3 which you can enrich with a good organic fertiliser. Chicken pellets are good, but they do tend to pong rather bad, so you might want to use a proprietory organic fertiliser.

Make a hollow in the compost to place your nut so that the sprout remains just above the surface. Do remember to leave enough room at the top of the pot for watering. Water well and allow to drain. Top up the compost if needed so that the nut sits snug in the compost. Line pot saucer with pea gravel and place on it the pot. You need to keep the saucer topped up with water, but do not allow the pot to sit in water.

Your pot needs to be placed out of any drafts and away from doors and windows which are in regular use. Keep it near to a heat source to maintain a temp of 28-30^oC during the daytime and no less than 20^o at night. It will need as much light as possible, so near a south facing window would be best. Unlike most house plants, this will need direct sunlight. These temps could be difficult and expensive to maintain, so I would certainly suggest you invest in an upright polythene cloche. This will also help maintain humidity. Modern heating systems would leave the atmosphere far to dry for your coco palm. Mist the nut daily and ensure the pot saucer never dries out. Water frequently and feed well. A full strength liquid tomato feed would be a good all round fertiliser, but do be careful not to get this type of feed on the leaves. Manganese and magnesium are also beneficial as is boron.

Assuming your palm goes well, move it out of direct sunlight during the spring and summer if kept indoors. Though it will benefit from being out in the full sun on hot days, make sure you bring it in overnight if temps are liable to fall too low. Coco palms will not tolerate being cold.

Growth can be rapid, if it is not, then you do not have the right conditions.

Keep an eye out for pests such as thrips.

Don't expect your palm to produce fruit, only a mature tree will do so and I'm affraid coco palms rarely live that long as a potted plant. 5 or 6 years would be the best you can hope for.

[jules (OP)]

Thanks for all the help. The seed is still in its early stages of producing a root and shoot. So far, a large stubby rootlike growth has pushed out of one the eyes, now it is waiting for the next stage. I think the root and shoot will develop from this. The coconut is in a sealed plastic bag, with a little water inside, kept in a S facing window in a propagator set at 30C.  This stubby root, the plumule,  has a hard brown callus on the end, like cracked leather, which I hope is nothing serious. Is it too wet or too dry?
I am not looking to grow and fruit the palm, just wanted to see if a store-bought coconut could be germinated, especially after being told it could not. I have three others in similar conditions, and after 3 weeks nothing has happened. They all have liquid inside.

[Nizzle]

Hey jules,

Roots generally don't like light, so turn your nut in a way that the root is in as much shade as possible.
Also, the roots should not be too wet or too dry.. Too wet and mold or fungus might appear, and the root 'lacks motivation' to grow further in a quest for moisture. Too dry and it will shrivel away

[cheryl j]

Hows your coconut doing?

[jules (OP)]

Here's a recent photo of my best coconut, bought about 4 weeks ago from a local supermarket. The label had Ivory Coast as the origin. I soaked it in warm water for two days, and this was enough to start the germination pore swelling, and the circular cap was pushed off. A white root started to push out, and in a couple of weeks this had thickened into the greenish pyramid shape shown in the photo. There is now a root and the start of a leaf bud. I keep the coconut in a large sandwich box with a lid on and a little water inside. This box is in an electric propagator with a thermostat, kept between 27C and 30C. If you have any photos of similar successes, or failures to share, please let me know.


coconut.jpg (43.57 kB . 1143x760 - viewed 46009 times)

I chose a coconut which seemed more rounded and "heavier" than the others, which were more pointed. It had liquid inside. The germination pore also looked pale brown and convex, as if something was underneath it. Some coconuts had sunken dark brown pores, and I discarded these as not viable.

[jules (OP)]

Two earlier photos, showing the development of the germination pore and the first root.

noseed 2.jpg (23.11 kB . 735x489 - viewed 34660 times)

17thcoconut 2.jpg (18.77 kB . 799x531 - viewed 37711 times)

[distimpson]

this is interesting stuff, wouldn't have thought it could work, now I'll have to try it too, thank you!

[SeanB]

I planted one about 30 years ago that I found on the beach, which had germinated. Now it is doing well in the garden, and is about 8m tall. Unfortunately we moved from there a long time ago, though now you can see it from the road. There are ones in the city that are over a century old and which are doing fine and bearing fruit regularly.

[jules (OP)]

this is interesting stuff, wouldn't have thought it could work, now I'll have to try it too, thank you!

Give it a try....let me know how you get on, and post some pictures of your coconut!

[jules (OP)]

I planted one about 30 years ago that I found on the beach, which had germinated. Now it is doing well in the garden, and is about 8m tall. Unfortunately we moved from there a long time ago, though now you can see it from the road. There are ones in the city that are over a century old and which are doing fine and bearing fruit regularly.

which beach, and what city?

[jules (OP)]

I have been trying this for several months and have an update on the progress. Most store bought coconuts germinate, with a small root appearing from the larger germination pore after 2-3 weeks. The coconuts are in a sealed bag with a little water, kept at 30C. The next stage is that the root either withers and dies off, or gets larger and the start of a leaf shoot can be seen. The root seems to get brown and calloused at the end, and stops growing. I am not sure why most seeds do not reach the last stage, even if kept warm. Are they too dry or too moist? Not sure they should be that fussy. The ones I have seen in the tropics come up like weeds everywhere.

[jules (OP)]

Update on photo. Shoot is about 7cm tall. Some large roots are growing as well.

2014-01-21 16.21.01.jpg (70.4 kB . 504x378 - viewed 36370 times)

[CliffordK]

Excellent.

Are you about ready to pot it?
What kind of soil?  Beach sand?  Ordinary Dirt?

I wonder if it will be possible to keep your tree under 7 feet or so, and productive.  Good luck.