I am sure that you are all familiar with the Horse Chestnut tree, but maybe you only notice it in the autumn when it is producing beautiful, glossy conkers. We have been looking at the Horse Chestnut trees around our village recently, as they are looking quite pretty at the moment with all their white ‘candle’ type flowers. Hopefully, with all your KS2 science knowledge, you can make the connection between these flowers and the conkers that you collect in the autumn. The flowers that are out now are hoping to be pollinated by insects so that they can grow seeds (ie conkers) that will eventually grow into new trees.
If you can find a Horse Chestnut tree with the flowers low enough to look at, you may notice something interesting about the colours inside the flowers. Although the petals are white, some of the petals have colourful ‘blotches’ on them, but they are not all the same colour. It seems that some of the blotches are pinky red, whilst others are yellow. It is thought that this might have something to do with whether the flowers have been pollinated or not. Look at the photo below, and you can see that some flowers have yellow blotches and some have pink. (Sorry my photo is a bit blurry - the camera on my phone is rubbish!)
Here is a link to an investigation that some children have undertaken, if you live near a Horse Chestnut tree, maybe you could do some of your own investigations and see what you can find out.