Tiny Urban Patio and a Toddler

We have a tiny outdoor space that we love.  Last year we updated the furniture to create more lounge seating instead of an eating area.  A narrow ikea couch, 2 Solair chairs, an outdoor rug and lots of greenery have given us a little oasis in the city.  Yet, while comfy and as well laid out as possible on our tiny patio we still need to entertain our 2.5 year old out there.  With a typically short attention span and a love of destruction, here are the activities that have kept his attention:

Bubbles - first blowing them himself and then me blowing them until i'm not looking and he dumps out the entire container

Bubble Gun - I call it a "machine" but a little battery operated bubble gun has saved my breath and entertained him longer than classic bubble blowing

Side Walk Chalk - so far this has only lasted a few minutes and usually ends with him bossing around the nearest adult to draw him Thomas, Please!!! But I'm still hopeful this will gain momentum.

Watering the Plants - with the hose, this requires supervision (or everyone and everything gets wet) but he loves helping and caring for the plants.

Playdough - We're going to try playdough outside but I don't find it holds his attention for very long inside.

Kiddie Pool - We had a baby pool last year that he loved so I think I will try this again this year when it gets a bit warmer.

Our small outdoor space does not replace getting outside and running freely which we do at nearby parks, by going for neighborhood walks and run-bike rides. But my hope is that our city patio can be a secondary play area for messier fun activities for him.  

Do you have any ideas, tips or resources for small outdoor activities you can share with me?