What a mind-blower "plant experiment"! :

That is amazing!!!! arn't plants clever :))

Do you think it's trying to escape, N2? LOL.

Well that's a mystery - a bit Edgar Allan Po ! Spooky.

the wet lava sand will be acting like cement. the roots are pushing down but the 'cement' is resisting and as a conseqnce the roots are growing but the bulb is lifting. Does that make sense? the other compost has more air spaces and places for the roots to grow into.

Interesting experiment, n2. I have never seen anything like this before; it looks as if the bulb is saying "I don't like this, get me out of here!" Whether Seaburn is correct or not I don't know; but it is a very plausable suggestion. Keep on with the experiment but be ready to give the plant some support when it starts growing leaves and flowers or it will fall over.

Bulbaholic, Seaburngirl raises an interesting point!
When I hydrated the lava sand, it compacted down by about 1/3 of its' volume and I had to add more. When it is barely moist, it is indeed like a cement slurry.

I will be closely watching the bulb to see what happens and if it starts to show any signs of distress from the experiment, such as an influx of predatory insects, leaf fungi, or foliage wilt, I will "bare root" it into super rich organically amended soil to save it. I just hate loosing any plant, even experimental ones!

Plants are SO fascinating to study and watch! :-)
~N2~

So I was right - it iS trying to escape! Clever bulb. I'm glad to hear that you're ready to 'rescue' it, N2.

have a look at my latest blog on primula flower form. now that is clever. the plant not the blog :o)

Seaburngirl, I read the blog and that was awesome! I knew that some of my plants were "gene challenged", but never knew exactly WHY.
Brilliant blog and great documentation on the photos! WELL DONE!
------> Slapping his forehead! Wow, I learned something cool! {Big grin}
~N2O~

I agree, N2 - I like learning new things! It keeps our brains ticking over. :-)))

well thank you kind people. I cant help sharing these wonderful nature bits. i drive my children mad sometimes.

*** UPDATE***
The "rising bulb" needed a little intervention today!
Seaburngirl was exactly correct about the lava sand being a tad too compacted to allow root growth.
I gently pulled up on the bulb today and its' entire root system was only 1/2 of an inch deep in the sand. It had started loosing that vibrant green color that the other one in the pot had. I dug out a nice hole in the sand and replaced the bulb deeper so that all of the roots were in the moist slurry.
We'll see what happens in the next few days. If It continues to keep rising in the container, I'll just plant it in some good organic potting soil and let 'er rip! :-)

I may dry root the little guy into some expanded shale and see what happens.
Expanded shale is like 1/4 inch gravel, but it has a huge surface area that retains water. My thinking is that the larger particles will allow better root penetration into the growing medium.
~N2O~