(Editor's Note: This article was originally published on June 24, 2008. Your comments are welcome, but please be aware that authors of previously published articles may not be able to promptly respond to new questions or comments.)
With their stunning flowers and stiff foliage, these plants make wonderful editions to your greenhouse. There are so many wonderful flowers and colors now that you no longer need to look at the popular bedding plants for inspiration. Rex begonias in particular are grown more for the leaves than the flowers. The patterns can be in tones of red, green, white, or silver. These plants need high humidity to really put on a show but they will grow in more arid areas. Keep plants in the 60s for the best blooms and leaves. April is the best time by most figures to move your begonias up a pot size. They are easy to grow from leaf cuttings. Thank you to lupinelover for the image.
Pocketbook plants have been a long favored greenhouse plant for many years. The exotic blooms come in a huge array of colors and blends of color to fit into any tropical greenhouse paradise. Many of the new hybrids are great for quick and large plants with quick and huge blooms. They are highly preferred to the older plants and species plants. They do not like rapid changes in temperature or light, so take your time in making any moves with this plant. Thank you to Floridian for the image.
The daisy-like flowers of Cinerarias develop in a cool greenhouse from December until June. The flowers are often very bright and can have white on the petals. With single and double flowers on the market, look around before you buy to make sure you love the plant you are getting. Few people keep the plants after they flower but it can be rewarding to keep them growing. Thank you to ampy for the image.
These graceful and sweetly scented plants are simple to grow in a greenhouse. The leaves are stunning, often with silver markings on them. Repot tubers in the summer for fall to winter blooms. To bring about flowering, plants like cooler weather and you might have to play with moving them in and out of the greenhouse to get blooms. Once you have mastered what it takes, these are wonderful and very rewarding plants to grow. These plants will bloom out in time, but you will have several years of wonderful blooms before that happens. Thank you to Howard_C for the image.
These plants are easy to grow if you can keep them free from the hottest heat of summer. The hanging and trailing types are by far superior and are wonderful in the greenhouse to hang from the top and allowed to hang down. Reduce the water in winter but keep moist the rest of the year. Right when you see buds first start to form, many gardeners pinch these back to allow more blooms and better growth. Thank you to Zanymuse for the image.
Why grow this plant in the greenhouse year in and year out when they are so easy to find and buy each year? The bigger the plant and the older the plant - if it is well cared for-- the more blooms the plant will have. All geraniums need good drainage and moist soil. Too wet and the stems will rot off and you will loose the plant. Too dry and the plant will quickly wilt beyond recovery. Geraniums root easily from cuttings taken in summer. Thank you to Happenstance for the image.
This includes three plants that are often used in greenhouses. German Primrose is a perennial which almost always has a show of blooms, Fairy Primrose is a biennial that grows rows of dainty flowers, and Chinese Primrose, also biennial, will have just a few stems of wonderful flowers in early spring. Keep plants shaded and never let the greenhouse get below 45 degrees for a good show in the spring. Thank you to Baa for the image.
Called Butterfly Plant and Poor Man's Orchid, they are annuals that can be grown in the greenhouse as biennials. Grown from seeds, just keep them frost free and above 32 degrees in winter to have these wonderful flowers in the spring to come. Thank you to wannadanc for the image.
I hope this will give you inspiration for simple and easy plants for your greenhouse before you dive into the wide and crazy world of tropicals. Give them a try and see if you don't love the look and feel of flowers in those cold winter months that are fast upon us.