Plant flowers in a location that gets at least six hours of sunlight daily for the biggest blooms in July. Afternoon shade is beneficial if you live in a desert location or in the Southwest to protect the plants from becoming scorched. Choose flowers that are known to produce blooms in July in your region.
Dig a hole that is at least 6 inches deep. Add well-rotted manure or compost to the soil, mixing it in. Apply a time-release fertilizer, following the directions from the manufacturer. These substances make the soil more fertile, promoting blooms well into the summer. Till the soil again to combine the ingredients.
Plant the tallest flowers at the back of the garden if it backs up to a wall or fence. Decrease the height as you move to the front to avoid casting shade on the flowers. If your garden is in the center of your lawn, put the tallest flowers in the middle, medium around them, then the shortest on the perimeter. Mix up the colors for an interesting array of blooms or stick to a pattern of coordinated colors. Different colors resemble a meadow of wildflowers, whereas coordinated colors look more manicured.
Spread mulch around the base of the plants to retain moisture and cut back on weeds. You'll notice larger blooms in July if you keep a couple of inches of mulch down.
Water the garden 1 inch per week if it hasn't rained enough. The best time to water is in the morning. Evening watering may make the flowers more susceptible to pests and fungus diseases.
Weed flower beds because the weeds steal nutrients from the flowers. Remove blooms once they shrivel up to make way for new blooms. Pinch back annuals such as petunias and snapdragons to encourage a second wave of blooms. Harvesting lavender promotes more blooms. Cut back babies breath, phlox and delphinium for a second flowering.
Flush out salt deposits from plant pots with water once during the summer. The salt builds up on top of the soil and causes the leaves to burn, resulting in a less vigorous plant.