Plant of the Month
AUTUMN SAGE, Salvia Greggii
By Dr. William C. Welch, Landscape Horticulturist
Occasionally, the common name of a plant is a bit misleading. The name őAutumn Sage‚ conjures the image of a fall-flowering herb, yet Bailey Hortorium‚s Hortus Third describes this plant as a fall-flowering sub-shrub. My experience with the Autumn Sage over a twenty-year period has been that it is almost constantly in flower from late spring until hard frost. Robert A. Vine‚s book, Trees, Shrubs, and Woody Vines of the Southwest, contains a more accurate description of the flowering habit, indicating summer and fall flowering on the shrub up to 3 feet. The species name őGreggii‚ honors Josiah Gregg (1806-1850), an early American explorer and botanist. S. Greggii is native to dry, sunny sites in southern and western Texas and New Mexico. It may also be found in the Mexican states of Coahuila, Sonora, and Durango. Although generally ignored by most nurserymen and home gardeners in this century, S. Greggii was a frequently-found plant in the cottage gardens of early Texas. Once established, the plant usually thrives on existing rainfall. It does need at least tolerably good drainage, and thrives in full-sun or partially-shaded exposures. Thanks to increasing awareness about the plant among Extension horticulturists in Austin, San Antonio, and other areas, S. Greggii is now beginning to be utilized.
In recent years, the discovery of a broad range of colors within the species has greatly increased their landscape value. Pure white, rich red, pink, and salmon have now joined the more common purplish-red selections. Flowers appear in terminal racemes, are tube-shaped and two-lipped, and about one inch long. Leaves are opposite, narrowly oblong, with blade length 1/2 to 1-1/4 inches long. The foliage has a pleasant, spicy scent. Propagation is usually from cuttings taken during the growing season. Landscape uses of Salvia Greggii are many. It is a natural for use in containers, masses, or borders, for low-maintenance landscape color. In landscape developments where a refined look is desired, the plants respond very well to periodic shearing, to remove old flower stems during the summer. Occasional light applications of a balanced fertilizer, and irrigation during unusually dry periods, will ensure repeat flowering from May through November in most of Texas. Little is known about the winter hardiness of Salvia Greggii north of the Dallas/ Fort Worth area, but West and South Texas are excellent locations. Well-drained sites in East Texas produce handsome specimens. Salvia Greggii is a beautiful, practical source of landscape color in most of Texas. It is another example of őrediscovering‚ plants that were popular in the early gardens of Texas, but ignored by most people in the recent past. It will be available this year from Texas wholesale nurseries specializing in native plants, as well as garden centers in much of the state.
Lawn and Garden News
őTOP EIGHT‚ CRAPE MYRTLE CULTIVARS FOR LOUISIANA
By Allen D. Owings, Associate Specialist (Horticulture) and Gordon E. Holcomb, Professor (Plant Pathology), Louisiana State University, Baton Rouge.
Crape myrtles (Lagerstroemia indica, Lagerstroemia indica x faurei) continue to be one of the most widely used landscape trees in the southeastern United States. Over the last several years, the Louisiana State University Agricultural Center has evaluated numerous cultivars for susceptibility/tolerance to powdery mildew and Cercospora leaf spot, two of the most prevalent diseases of crape myrtles in Louisiana. Flower performance and growth habit also have been observed. The following is a list of the „top eightš crape myrtles for Louisiana, as recommended by the Louisiana Cooperative Extension Service:
Natchez is recognized as the top performing crape myrtle in the southeastern United States. It was introduced by the U. S. National Arboretum in 1987. White flowers and exfoliating bark are characteristic of this cultivar, which reaches heights of 30 feet at maturity. Bloom period is about 110 days in Louisiana, starting in early June. Very large blooms.
Muskogee was introduced in 1978, and has medium-size, light lavender flowers. Blooming period is excellent, beginning in mid-June, and lasting 110 to 120 days. Some years, flowers are as early as late May in Baton Rouge. Good tolerance to powdery mildew and leaf spot. Exfoliating bark is grey-tan to medium brown. Bark characteristics are desirable, but not as good as Natchez and Tuscarora. Reaches a mature height of over 20 feet.
This cultivar was introduced in 1981, and is characterized by coral pink flowers. It is less susceptible to powdery mildew and leaf spot than most cultivars. Flowering begins in late June or early July, and will continue for 70 to 80 days. The trunk has mottled, light-brown bark that exfoliates increasingly as the tree ages. This cultivar can easily reach heights of 25 feet in the landscape, and has performed well in landscape plantings across Louisiana.
Tonto is a semi-dwarf to medium crape myrtle, reaching heights of 12 to 14 feet. It was released by the U. S. National Arboretum in 1990, and has been recognized as a Georgia Gold Medal winner (1996) and Mississippi Medallion plant (1999). Excellent resistance to leaf spot and powdery mildew. Good foliage retention into the fall months. Flowers are deep red. Satisfactory exfoliating bark.
Basham‚s Party Pink
Basham‚s Party Pink is a tall-growing hybrid cultivar introduced to the nursery trade by Texas nurseryman Lynn Lowery in 1965. Blooms are lavender-pink, and compete with Natchez for size. Very comparable and similar in performance to Muskogee. Good resistance to leaf spot and powdery mildew in LSU Agricultural Center evaluations. Cold hardiness is not as good as Muskogee.
Acoma was introduced by the U. S. National Arboretum, and reaches a height of 10 to 14 feet, similar in size to Tonto. Weeping/cascading type growth habit. White flowers appear in mid to late June, and last around 90 days. Powdery mildew resistance is good. Some years, leaf spot is observed on this cultivar; defoliation is not a problem.
Sioux has been recognized as a Georgia Gold Medal winner (1996) and Mississippi Medallion plant (1999). Good powdery mildew resistance in LSU Agricultural Center trials. Some susceptibility to leaf spot. Flowers are vivid pink, and last from June through September. Mature height ranges from 10 to 15 feet, but can be widely variable.
Tuskegee was introduced in 1986. Flowers are dark pink. Typical average height is 15 to 20 feet. Excellent resistance to powdery mildew and Cercospora leaf spot.
TIME TO PLANT CALADIUMS
By William D. Adams, Harris County Extension Horticulturist, Houston, Texas
Late April or early May is caladium planting time. Whether in pots or shaded garden beds, caladiums add a vivid richness to any summer garden. The caladium is a warm weather plant, and does best when planted after the soil warms up to 70 degrees F. or more. Even though Caladiums like warm temperatures, they prefer cool, moist, well-drained soils in the landscape. The tubers should be planted approximately 1-1/2 to 2 inches deep, and from 12 to 18 inches apart, in loose, organic, rich soil. They are excellent in pots, tubs, and planters. You can get a jump on the weather by planting in mid April in pots, and transplanting to the garden in early May
OUR VEGETABLES‚ ANCESTORS WERE ALSO FOREIGNERS
This article originally appeared in the section contributed by Dr. Jerry Parsons of PLANTanswers at the aggie-horticulture web site: http://aggie-horticulture.tamu.edu/
North Americans, and most of the vegetables they eat, have one thing in common -- most of their ancestors were foreigners. Even the name by which vegetables are identified on the market -- őtruck crops‚ -- is foreign, and has nothing to do with transportation. Only nine of the nearly fifty vegetables which have become common to the American table are natives of the Americans, and they (corn, white potato, sweet potato, lima bean, common bean, tomato, squash, summer squash, and pepper) all originated in Central and northern parts of South America. Those requiring colder climates, like the white potato, originated in the Andes mountains, while the sweet potato developed in hot, moist climates at sea level. The list of vegetables that North Americans have adopted is long (numbering at least thirty-eight), but their everyday names conceal the faraway places of their origin: the eggplant and cucumber come from India; spinach and muskmelons from Persia; watermelon from Africa, which also sent okra; radishes and Chinese cabbage from China; asparagus, kale, and collards from the lands of the Mediterranean, which also sent us cabbage; garden peas from Asia; and kohlrabi and Brussels sprouts from northern Europe. Other őforeigners‚ now in our diet are broccoli, cauliflower, artichoke, beet, rhubarb, parsnip, salsify, celery, parsley, leek, Swiss chard, turnip, rutabaga, cowpeas, Indian mustard, Chinese mustard, lettuce, carrot, onion, garlic, and chive. őTruck crops‚ is the commonly heard expression to cover all vegetables, but it has no connection with the fact that a good many of them are hauled to market on trucks. An old meaning of the word őtruck‚ (derived from the French word troquer) is őto barter or exchange‚. The word developed a special meaning as a synonym for vegetables in general because of the practice of bartering or dealing in small lots of them in the marketplace.
The growing, marketing, and consumption of vegetables in the United States today has come a long way since small lots were bartered. The field-to-table story of today‚s vegetables is a story of big business, and it is sometimes because of the needs of commerce that a fruit is a vegetable, or a vegetable is treated as a fruit. The tomato is an example. Botanically speaking, the tomato is a fruit, but legally speaking, it is a vegetable; the Supreme Court of the United States said so in 1893. An importer had argued that tomatoes were fruit and, therefore, not subject to a duty in effect at that time. The Court held that the tomato is a vegetable because it was usually served at dinner in, with, or after the soup, or with fish or meats that constitute the main part of a meal. This is less true now than it was then, for today, a much larger part of our tomato crop is made into juice; however, the tomato remains, legally, a vegetable. Botanically speaking, snap or green beans, the pods of peas, the garden pepper, the okra pod, and many others, are also fruits. But no one doubts that they are vegetables. The cucumber and muskmelon are closely-related fruits; both are the genus Cucumis. They are similar in habits of growth and in structure, both are grown by truck farms using similar methods, they move through the same channels of trade, and both are eaten raw. Yet we always think of cucumbers as vegetables and of muskmelons as fruit. While it is custom which seems to dictate which plants are treated as vegetables and which as fruit, regardless of how they may be classified, they all taste great when grown in, and harvested fresh from, the home garden!
Dr. William M. Johnson, Galveston County, Extension Agent and Master Gardener Coordinator, included this article in the March 1999 „Master Gardener Network Newsletter.š
By Dr. William C. Welch, Landscape Horticulturist
+ Prune spring-flowering shrubs soon after flowering. Keep the natural shape of the plant in mind as you prune, and avoid excessive cutting except where necessary to control size.
+ Roses have high fertilizer requirements. For most soils, use a complete fertilizer for the first application just as new growth starts; then, use ammonium sulfate or other high-nitrogen source every 4 to 6 weeks, usually just as the new growth cycle starts following a flowering cycle.
+ Continue to spray rose varieties susceptible to black spot, using a spray containing triforine or, as it is more commonly known, Funginex. Use every 7 to 10 days.
+ Climbing roses may be pruned as soon as they complete flowering.
+ Removing spent flowers, trimming back excessive growth, and applying fertilizer to an established annual bed can do wonders towards rejuvenating and extending the life of the planting.
+ As soon as azaleas have finished flowering, apply an acid type fertilizer at the rate recommended. Don't over fertilize, as azalea roots are near the surface and damage can occur. Water thoroughly after fertilizing.
+ Seeds of amaranthus, celosia, cosmos, marigold, portulaca, zinnia, and other warm-season annuals can be sown directly in the beds where they are to grow. Keep seeded areas moist until seeds germinate. Thin out as soon as they are large enough to transplant. Surplus plants can be transplanted to other areas.
+ It will soon be time for bagworms to attack junipers and other narrow-leafed evergreens. Control measures, such as Sevin dust or spray, should be applied while the insects and the bags are about one-half inch in length.
+ For instant color, purchase started annual plants. Select short, compact plants. Any flowers or flower buds should be pinched, to give plants an opportunity to become established.
+ Check new tender growth for aphids. A few can be tolerated, but large numbers should be controlled. Always follow label instructions on approved pesticides for control.
+ Many flower or vegetable seeds left over after planting the garden can be saved for the next season by closing the packets with tape or paper clips, and storing in a sealed glass jar in your refrigerator.
+ Start weeding early in the flower garden. Early competition with small plants can delay flowering. A mulch will discourage weed growth, and make weeds that do come through easier to pull.
+ Soil purchased for use in beds, low areas, and containers should be examined closely. Often, nut grass and other weeds, nematodes, and soilborne disease are brought into the yard through contaminated soil sources.
+ Watch newspapers and other publicity for information regarding wildflower trails, and plan to take a trip to enjoy this beautiful natural resource.
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