This will force air out of the pore spaces and help help keep the soil moist. Put casters on wooden planters or put large pots on a dolly before they're filled with soil. A 30-gallon planter can weigh more than 200 pounds. Mix a slow-release fertilizer into the soil at planting time to guarantee plants a strong start. A dose of liquid fertilizer every few weeks will keep them healthy into fall.
Containers fend off heat and wind better if several are arranged close together.
Direct contact can destroy tiny feeder roots. Shield container plants from midsummer heat by using a lattice, awning, umbrella or shade fabric. Potting soil can be used two or three years, unless plants become diseased. Results are best if the soil is changed every year, however. To save money, replace only the top half of the soil layer in deep pots.