Plants referred to as "strong" or "hardy" are ones that are adaptable and tolerant of harsh conditions. These strong plants can be used in many different applications, from gardening in a difficult spot to container gardening in full sun. The best strong plants for direct sun will thrive in full sun and be highly adaptable, with many tolerances.
The coral honeysuckle (Lonicera sempervirens) is a part of the honeysuckle family. It is an easy to grow vine that attracts songbirds, hummingbirds and butterflies. It is good for containers. Leaves are smooth and 1 to 3 inches long. Tubular flowers, 2 inches long, are red or orange. Fruits will be red-orange berries. Grow a coral honeysuckle in full sun in any soil. Propagate via seed. It is drought-tolerant, adaptable, and very hardy.
The moss rose (Portulaca grandiflora) is part of the purslane family. It is an annual that is drought-tolerant and good for containers. It will get 6 inches tall and 12 inches wide. Leaves are thick and bright green, 1 inch long, and pointed at the end. Flowers are 1 to 3 inches wide and in colors of orange, white, red, pink and yellow. Grow a moss rose in full sun in poor soils. Propagate via seed. Besides its drought tolerance, it grows well in bad soil.
The common snapdragon (Antirrhinum majus) is part of the figwort family. It is a fast growing, easy-to-grow plant that is attractive to hummingbirds. It makes a good container plant. Depending on cultivar, it can range from 4 inches to 3 feet in height and colors are an assorted rainbow. Grow a common snapdragon in well drained soil in full sun. Propagate via seed. They may self sow.
The corander/cilantro plant (Coriandrum sativum) is part of the carrot family. It is an annual that attracts butterflies. The kitchen seasoning coriander comes from the seeds and the seasoning cilantro comes from the leaves. It will get 2 to 3 feet tall and 1 to 2 feet wide. Leaves are 1 to 2 inches wide. Leaves are fernlike. Flowers are small and white or pink. Seeds will be in yellow brown pods. Grow coriander/cilantro in full sun in any soil. Propagate via seed.
The pineapple (Ananas comosus) is from the pineapple family. It is an easy-to-grow perennial that is good for containers and for indoor use. The pineapple has stiff dark green leaves 3 feet long. A 12-inch cone cluster of purple blooms, which comes in summer, gives way to the juicy, popular fruit. Grow a pineapple in full sun with regular watering. Propagate via offsets.