If you pull out the ones you are willing to give up, it could mess up the roots of the ones you leave. Best to cut off some of the ones you can part with at soil level. If they resprout, keep pinching them off. Likely the roots left over will be crowded out by the plants you leave.

While I grow a lot of soybeans, I confess that I have never tried them in containers. However, a healthy plant takes up about as much space as a bush bean. The 6" spacing cited by Ikea will produce bushy plants. It's also woth noting that the healthier the plant, the greater number of pods with 2-3 beans... if spaced too closely, you will get a higher percentage of single-seeded "pollywogs". Since soybeans have large root systems, my recommendation would be to allow about a gallon of soil for each plant. There are 231 cubic inches to a gallon. As a frame of reference, at 6" X 6" X 6" depth, the root area per plant at Ikea's spacing would be 216 cubic inches. If the depth of soil in the pot cited above is 5", you would have about 300 cubic inches... so for best results, I would recommend one or two plants only.

If you only planted up last week or so - the little plants will probably still be 'thinking' about extending their roots out from the shape they were last in (punnet-shape) so it would be safe to just loosen them gently with a slim trowel ot pot gardener's hand fork - and put them into another prepared container. If they've been there a while (month or so) they'll be out and foraging with their roots. As lindac says - reliable and regular water and food - and you'll be in for a glorious display. Keep taking off the spent heads and pinch back any straggling stems and you're likely to have flowers until the first hard frost. (The petunias might go off but the pansies could go on for a while longer. A small feed of slow release and some sun shelter should keep them happily flowering.)

gerris2, the pole is 28cm, or 11in in diameter. Thank you for all your advice... I bought a bunch of flower seeds from the US... it is winter here now so the temperatures are in the high 70s, low 80s right now. It should go down to the low 70s in the next month or so. I will be growing the MGs in Smart Pots (fabric pots). seeds for Heavenly Blue, Split Second, and also Moon Vines have sprouted for me. I think I only have room to try the Heavenly Blue and the Moon Vine... I am trying to think of another place I can grow the Split Second ones... I don't want to have to let the seedlings die... I might try to create some kind of stake thingy out front of our house and let them grow there... As for cleaning the vines once they die yes, I do have a ladder... if it is too much of a pain to clear out the dead vines, I will wait to try to grow them again until we move to find a better place for them to grow. ron_convolvulaceae, thank you--I will put up some kind of mesh for them to hopefully get them to start climbing the pole :) There is plenty of sunlight... right now in that photos a tomato plant in a Smart Pot in front of the pole... I will be moving that to another location to put the Morning Glory pots there instead. dena_eft 7, I am going to go ahead and plant all the seeds that germinate and see what happens... so far 3 Heavenly Blue seeds and 2 Moon Vines have germinated.... oh yes, and 2 Split Seconds...but I will not grow those in that location...trying to think of another place as I mentioned... :)