I've raised £700 to help teach kids in Hackney about nature and turn the neighbourhood 10x greener

This weekend I'll be trying to run the Hackney Half Marathon. I've never run 21k, I don't know what a 'gel' tastes like and I'm not sure what I'm dreading more -- the distance or being outstripped by the Shoreditch hipsters.
I'm hoping to raise some cash for a cause that is close to my heart and my hood. The scheme helps kids and families from the community connect with nature - ranging from local workshops focused on growing veg to helping out at the local community garden Etc. Any donations will go towards funding a community gardener to run the scheme for a year (7.5K). I'm hoping to raise £700 towards that. Any contribution, no matter how small, would be amazing. If not, then just send me brave thoughts for Sunday, eeeek.