Build a pyramid planter for your strawberries. Each hole in the concrete block will hold more than enough soil for a strawberry plant. Wooden pyramid options I've seen waste too much soil under unused space. Once the plants grow in.
Strawberry Pallet Planter - A practical DIY tutorial showing how to make this strawberry planter out of a single pallet. Just make sure your pallet isn't treated with chemicals before using it to grow your food ;