This short time lapse clip shows runner bean seedlings emerging from the ground, climbing up bean poles, flowering and, eventually, producing beans. Children who are waiting for their own beans to grow might like to watch these beans growing, apparantly at the speed that Jack's beanstalk gew! They could create their own photographic record of their beans, to show the change over time as the plant grows.
If you are growing runner beans with your class how about growing several varieties? Children can explore the seeds which come in a range of colours and patterns. Then they can work scientifically by observing how the beans change over time and by comparing how the different varieties grow.
Perhaps they could do a seed trial for Jack and let him know what would be the best variety to grow? Which variety grows the tallest? Which one has the most beautiful flowers? Which has the biggest beans? The most beans? The tastiest beans? Perhaps they could write a report for Jack.
Do be aware that the beans might start fruiting in the summer holidays. If they are picked regularly over the holidays they will still be cropping when the children come back in September. Don't forget that beans need to be grown up poles. These can be arranged in a wigwam and can double up as a den for the children.