Pour casting concrete into rubber gloves, being carefully to remove air bubbles from fingers. Mould into position working fast before concrete sets. When set, peel of rubber gloves revealing your concrete planter.
Grow sweet strawberry in a vertical PVC tube is great solution for small garden or yard. Vertical planter will save you a lot of space, at the same time keep plants out of reach from garden insect pests AND enable you to switch to hydroponics.