Strange leaves appeared in pot

Yesterday I found some strange, single spear like leaves had appeared in a pot in the garden. Obviously deliberately planted because they were growing in neatly consentric circles. I didn't remember sowing anything and didn't recognize the leaves at all.
Single elongated spear shaped leaves, dark green and deeply ribbed.
In the early hours of this morning I was lying in bed cogitating, as one does in the early hours, when I remembered planting some date stones after Christmas. I was emulating my grand mother who was very green fingered and grew all sorts of things from pips, stones, seeds etc. I planted about a dozen as I didn't think the germination would be high, if at all.
It looks as if I have 100% germination as there is a mini forest in the pot. Now what do I do with them? The only thing I can think of is to pot them on, grow them on and donate them to a local community garden group in a nearby village as I am not brilliant at looking after house plants and I assume they will not be hardy outside. I have a small unheated greenhouse where I could over winter them but am not sure if they need more warmth.

 

Dates are not hardy as you say, and would probably prefer a bit more warmth than a cold greenhouse, (unheated), they are quite slow growing and could be three or four years before they even look like a palm, TBH.
The seed puts out a long root before you even see any top growth so if you want to pot them singly it might be best to do it sooner rather than later.

 

Thank you Pete.
I have just looked at the pot again and there are roots coming out of the bottom of the pot so I shall have to get them potted on soon. I am guessing long pots might be better than standard pots. I could move them into an unheated conservatory, double glazed or even the dining room window sill, again no heating. I think I might pot them on, 6 in each pot and then 3 to a pot etc., until they are bigger. I remember my grandmother having a large spiky plant growing on one of her window sills, I seem to remember it was multi stemmed rather than a stick with a tuft of leaves at the top. I wonder if she grew 2-3 stones close together?

 

Lots of people do use longer pots for palms, probably a good idea about potting more than one in a pot if you want it for a house plant. I think as long as they are frost free and in a sunny position they will survive OK, perhaps won't grow much between now and next spring.

 

That reminds me on the end 80's when we were able to buy dates. It didn't take long and we let them germinate, including me. I had the pots on the heating, which works 100% (as yours).
Some of the smart ones offered them for sale when they were tiny. What I learned quickly with my own attempts is that once the have come out, they go through a crucial stage and 90% will fail to grow and die. There will be one or two that will make it.
From my experience since then, I would pot each of them into a single pot, don't over water them, keep them warm and sunny, but not too sunny. If you are lucky, one or two will make it.
They need many years to be too heavy. I would have them outside in early summer and and take them in in later summer if not Autumn, and store them in a room with no more than 17c. The next year, I would adjust the time outside and temperature to get them adapted to Cornish climate.
I had to say goodbye to my date that survived after 15 years, when it was too high to be inside a 3,20 m room in Berlin. And the pot was too heavy.
I tried to germinate them last year, but it's not warm enough and we have no chance to store the pots on the radiators. I would love to have one just to experiment.