When I was teaching some part of my summer school break (notice that I don't use holiday) was spent planning for the coming term.
If you are planning work on a school gardening project then you may find this area of my website to be of use It covers various aspects involved in the planning of a school garden area whether it is a vegetable plot, a sensory garden or a haven for wild life.It also covers choosing equipment and things to grow.
If you already have a school vegetable patch then the section covering what to do in September may be helpful.
Then you will need to consider how gardening activities can be linked into other curriculum areas so try looking at the section devoted to building curriculum links.
You may be planning to incorporate different opportunities for your pupils/students to share their literacy skills. Being a published writer is very motivational and many schools now have their own blogs and websites. If you don't want to go that far - why not get the children to prepare a guest post for this blog or an article to submit for inclusion into this section of my website. Obviously I can't include articles from every child in your class but you could whittle down submissions by having an in house choosing session first. Young children could submit a group post of either short phrases or art work linked to their growing experiences.
Any gardening related topic will be considered but you may prefer to email me first to check whether your choice of subject matter is appropriate. Please note that I will not include photos of individual children (or full names) and schools should ensure that any group photo has the appropriate parental permissions to be published.