Gardeners basically grow two types of plants, annuals and perennials. The annual plant grows from a seed; flowering follows and the mother plant dies after the new crop of seeds has matured. The perennial does not have a lifespan limited to one year unless grown outside the area. For example, the tulip bulb is a perennial when grown in the Netherlands, but in much of the United States, tulip bulbs decline and do not bloom again in many states, so tulips are planted at thereafter as an annual plant, not to say return the following year. Environmental factors of heat and humidity limit the planting and cultivation of tulip bulbs in much of the United States as a perennial.
Elephant ear bulbs can be grown as a perennial in warmer climates where elephant ear bulbs grow in size each year to form large clumps. Elephant ear bulbs when planted in northern states like New York will not survive outside temperatures of snow and ice and should be grown as annuals unless the elephant ear bulbs are dug up and stored indoors .
From these examples of perennial bulbs, it can be shown how important temperature factors are in plant survival. Other environmental factors are important, such as light intensity. Yucca and agave plants thrive in hot, dry, sunny conditions, and if any of these plants are grown in low light, decline begins that ultimately results in the death of the plant.
Desert plants, such as agave plants, yucca plants, and aloe plants, can survive in the dry sands of deserts and in heat, drought, and intense sunlight that other plants could not tolerate. Yucca, agave and aloe plants could not survive the humidity and shade of the rain forest.
Fern plants are highly adaptable to virtually any environment imaginable, from the rocky heights of arctic mountain tops, to the dense shade of tropical rainforests, ferns thrive. As a nursery plant, ferns are grown as garden plants in sun or shade or as delicate indoor potted fern plants, such as maiden’s lace fern, Adiantum peruvianium, and foxtail fern, Asparagus meyerii.
Perennial ground cover plants are important in controlling erosion and reducing evaporation from the soil. Some ground cover plants form clumps and others, such as ivy, form vines that can grow rapidly to cover bare spots uphill or cover walls and buildings. Ivy grows rampant once established and is popular for use in pots and hanging baskets. The iron plant, Aspidistra lurida, grows well as a shade plant, and some forms of aspidistra are covered with white dots on the waxy green leaves; others are variegated with white stripes, Aspidistra elatior ‘Variegata’. Palm grass, Curculigo capitulata, grows very well as a shade plant near swimming pools. Dwarf mondo grass, Ophiopogon japonicus nana, is an excellent iris-type groundcover that aggressively crowds out weeds and grows in green or white forms to create contrast in the landscape. The creeping fig tree, Ficus repens, quickly covers walls and can cover areas of the ground that are barren. Ficus repens, the fig vine, Kashmiri Kesar can quickly send out leafy shoots that grow a foot a week. Liriope groundcover perennials are among the most widely cultivated because they are colorful, dense, neat-growing, and grow to many sizes. The most popular liriope cultivars are Liriope muscari ‘Big Blue;’ Liriope muscari ‘Royal Purple’; Liriope muscari ‘Super Giant Green’; and Liriope muscari ‘Variegata.
Perennial flowering shrub hydrangeas are native to the United States, and many new hydrangea cultivars have been developed in bright colors of red, blue, white, purple, and pink. Hydrangea bushes lose their leaves during the winter, but come back to life in the spring, covered in flowers.
Perennial flowering vines are grown to cover fences, trellises, and walls, some with evergreen foliage, others with flowers a bonus of many colors, including red, coral, blue, purple, pink, white, and yellow. Carolina jasmine, Gelsemium sempervirens, covers the entire vine with bright yellow flowers, which are fragrant and fast growing. Confederate Jasmine, Trachelospemum jasminoides, flowers with yellow or white flowers, scented like other sweet jasmine vine perennials. heart vine