Ups and downs

I know that seeds germination is in the mind of all gardeners in early spring.
So, I will try to answer a question someone recently directed (as a comment): “Does anybody know the orientation of the root vs plant ends on the seeds?”

Due to spam attacks, I have been trying to block the comments, because of the huge amount of time needed to sort through the junk for the ‘good’ ones. Somehow they are sneaking through anyway. The above question seemed to be from a legitimate IP address, so let’s have a look at it.

If the question was related to sowing, here’s a simple answer. No matter how you place the seeds in the pots they will find their way, down and up! The roots will always orient in a downward direction and the shoots upwards due to gravitropism. It will not affect the germination or the health of the seedlings. Exceptions may apply only in case of very large seeds (next time about the skunk cabbage germination case); when in doubt, place them sideways.

The easiest way to exemplify this is by looking at seeds germinated out of pots from my ‘germination library’. Notice the Gentiana lutea germinating seeds in a Petri dish positioning by themselves with the roots ‘down’ and the plumule ‘up’. Also, an old image of a Sanguinaria canadensis seedling (part) found in the plastic bag ‘hanging’ to a vermiculite particle. An even better illustration comes from a ‘piece’ of Stylophorum lasiocarpum seedlings grown together in vermiculite in the stratification bag. No one arranged or told them which side is ‘up’ and which is ‘down’.

A couple more images showing germinated seeds of Helleborus caucasicus and Podophyllum peltatum (Mayapple) in moist towel. 
I added a few explanatory notes (click to open the gallery): regardless of the the position the seeds, the radicles are always heading ‘down’ (meaning the ‘down’ of towel). The seeds who were not in the ideal position, start curving their radicle immediately to grow it in the ‘right direction’. This is one of the reasons I do not germinate seeds in moist towel anymore: the radicles get tangled easily in the towel and are very easy to break when taken out.

Next time we’ll talk a bit more ‘serious’ about this subject, with a recap of the plant ovules and the post-fertilization marks that can be ‘read’ on the seedcoat surface.  Maybe that will scare the spammers away ;-)

Meanwhile, Happy Easter to all celebrating with a message of peace, joy, hope and happiness!