Recently, we planted a new addition in the Boettcher Tropical Conservatory, Brugmansia sanguinea</em>, or the ‘red angel’s trumpet.’ This crimson-flowered tree will surely be a treat when in bloom. Brugmansia</em> is a genus of trees and shrubs consisting of only seven species. These pendulous-flowered beauties are members of the Solanaceae family, commonly known as the nightshade or potato family, and this is seen through the flowers. Yes, it is true, that Brugmansias are related to potatoes and tomatoes, although you would not want to eat brugmansia. Many members of the Solanaceae family are toxic and Brugmansia is no exception. Brugmansia sanguinea</em> hails from the Andes and is native from Colombia to Peru and Bolivia. The genus Brugmansia</em> is broken in two sections: section Brugmansia,</em> the warm growing brugmansia, and section Sphaerocarpium</em>, the cool growing brugmansia. B. sanguinea</em> lives up to its classification as a cool-grower, and can withstand short frosts, although it doesn’t like temperatures under 32 degrees Fahrenheit for prolonged amounts of time. Brugmansia trees and shrubs make great houseplants, and many colorful hybrids exist that are readily available through a variety of nurseries. They may be kept in a pot on your porch during the summer and brought in for the winter. If you don’t have anywhere to store the potted plant during the winter months, you may prune it and store it bare-root in a cool, dry place and repot in the spring. This tropical gem is definitely worth a stroll through the Boettcher Tropical Conservatory, even if not in flower, but keep your fingers crossed as it has been putting out more blooms lately. You will find the plant towards the West end of the conservatory just past the pandanus tree. Hope to see you soon! For more information on growing Brugmansia sanguinea</em>, click here to visit the "Strange Wonderful Things" Web site.</p>
</p> Autumn is imbued with intimations of mortality: dying leaves, dormancy, doom, gloom, Hallowe'en colors and ghosts and spooks: Boo! Gardeners know another side of this "season of mists and mellow fruitfulness": there are a number of plants that only begin </strong>blooming in September, with one or another species coming on until the spring: Hellebores, crocuses, cyclamen and witch hazels are all plants that have a different notion of the growing season. It's their spring right now! A well stocked collection of any of these genera begins with heavy bloom in October and one or another will keep blooming right until the hot days of late spring when they go dormant (so to speak) for the summer doldrums. These are my kind of plants! Crocuses for most of us means the bright orangy-yellow Crocus flavus </em>or C. ancyrensis</em> among a host of others, not to mention the Dutch giants derived from C. vernus</em>. Although pitifully few Coloradoans grow them, crocuses will thrive almost anywhere they are planted in a Colorado garden: dry or wet, sunny or shady. They love it here. Now is a great time to plant these spring bloomers for a splash of color in February and March. There are another group of true crocuses that wait until October to put on their show. These you must order early in the season and plant in September preferably. Denver Botanic Gardens boasts wonderful plantings of these in many gardens: they are among the largest flowered plants in their genus and have flowers of a luminous shades of lavender, purple and occasionally white. Ten days ago we had a precocious bout of winter that froze many leaves and diminished our autumn beauty. But I have never seen the autumn crocuses bloom more spectacularly than they have the last few weeks. I am not talking about the pink Colchicums that go by that name (they are mostly done and are in the Lily family and have six stamens: true crocuses are related to irises and have only three stamens!). Above you have Crocus speciosus</em>, the commonest and bluest of the autumn crocus which is blooming in the east west pathway and the Rock Alpine Garden right now. Below is C. nudiflorus</em> in my own home garden. An even darker C. medius</em> will be blooming the next few weeks in the Rock Alpine Garden. Remind me to order more of these and the rest next year for my garden! To walk into a garden where dozens of unearthly, fluted goblets of autumn crocuses are gently trembling in the autumn breeze is heavenly. It's as though they are toasting the start of the crocus season with their beakers, full of sky blue or evening lavender. Cheers! </p>
Have you ever wondered what really happens within plants to help them carry on through the winter? As autumn approaches, the sun begins to set closer to the horizon, leading to cooler nights and shorter day lengths. This sends a warning signal to plants that winter is soon approaching and that they need to get ready to go into dormancy, which is similar to hibernation in animals. During dormancy, the plants stop growing, fluids within cells stop flowing and the tender growing tips are enclosed in a tight, frost resistant bud. Before entering this dormancy, the leaves of the plants turn from green to yellow, orange, or red before dropping to the ground. So, what causes the change in leaf color? In leaves, both the green chlorophyll and the yellow-orange carotenoid pigments occur within the chloroplasts. Since there are more chlorophyll pigments than the carotenoid pigments, the leaves appear green. In the fall, the chlorophyll pigments decompose allowing the caretenoids to express themselves as orange and yellow. In some plants, the leaf cells produce red pigments, the anthocyanins. In these leaves, once the chlorophyll has decomposed, the anthocyanins mask the caretenoids, thus turning the leaves red. The change in color and dropping of leaves are the plants' way of avoiding freezing damage to themselves. During freezing, the water within the cells of leaves turn to ice, causing disruption of the tissues. These damaged tissues become inviting sites for fungi and bacteria to invade the plant. In order to prevent microbial invasion, plants drop their leaves and form a protective seal over the areas where the leaves were once attached before the freeze damage can occur. Even though plants look lifeless in the winter, be assured that they are ever sensitive of their surroundings, keeping tabs on the temperature and day length before getting ready to spring back to life!</p>
