A base of bricks would be an acceptable alternative. Place a 2 inch layer of pebbles, coarse gravel, or broken flower pots in the bottom of the barrel. Then fill the barrel with loam or sandy loam up to the bottom row of holes. Pack the soil firmly and insert plants into the lowest row of holes, so the plant crowns are even with the surface of the barrel. Place only one plant in each hole.
Everbearing varieties are preferred.
Spread the roots out and cover them with soil. Follow the same procedure with the other rows. Pack the soil rather firmly to prevent excessive settling when the barrel is watered. Finally, set 6 or 8 plants in the top of the barrel. When the barrel is one-third full of soil, place on end, in the center of the barrel, a 3 or 4 inch tile, metal pipe, or wooden channel, long enough to extend up to the soil surface.