Plant of the Month... July / August

Transcription

1 Plant of the Month... July / August Gomphrena globosa, Bachelor Button Dr. William C. Welch, Landscape Horticulturist As we approach the most stressful period of the year for most garden plants, the few species that really thrive in hot, dry conditions deserve special recognition. Although rarely sold as a bedding plant, Bachelor Buttons are readily available and easily grown from seed. According to Hortus Third, Bachelor Buttons came to us from tropical areas of the Old World. They are documented as having been a part of early American gardens. Colors range from purple to rose, orange, and white; flowers are about 1 inch across. In addition to their ease of culture, Bachelor Buttons were popular with our ancestors for their use as 'everlastings'. Dozens of individual flowers occur on each plant, and they form attractive mounds about 2 feet tall and 2 feet wide. Cut stems of flowers, hung upside down in a dark, dry area and allowed to dry, hold their color for a year or more, and can be used in a variety of ways. Experienced gardeners always save a few flower heads from plants of their favorite color to use for next year's seed. This is definitely a hot weather plant that will not thrive until late May or June. May 1 is a good time to plant the seeds in most of Texas. Bachelor Buttons are so easily grown and transplanted that many gardeners simply sow the seeds in a small area of the vegetable garden or flower border, then transplant seedlings to permanent locations when 2 to 3 inches tall. Plants are usually spaced 1 to 1 feet apart for a mass effect. They are normally attractive in the garden until late fall. Seed sources such as Park Seed Company in Greenwood, South Carolina, list dwarf forms in both purple and white. They should be useful in borders or mass plantings, since mature height is described as 6 to 8 inches. Few insects seem to bother Gomphrena, but occasional loss occurs from root rot. Good drainage is essential, but little fertilizer and water are necessary to produce a massive display. It is not too late now to start new plants from seed. Plants started in July or early August can make a beautiful fall display, and provide lots of dried material for winter decoration. Educational programs conducted by the Texas Agricultural Extension Service serve people of all ages regardless of socioeconomic level, race, color, sex, religion, handicap or national origin The Texas A&M University System, U.S. Department of Agriculture, and the County Commissioners Courts of Texas Cooperating

2 Watering the Garden Dr. Sam D. Cotner, Head, Department of Horticulture With vegetable gardens in various stages of growth across the state, it is certain that most home owners will be concerned sooner or later about watering their gardens. When to water, how to water, and how much water to apply are questions asked continually throughout the gardening season. To many people, watering is one of the most enjoyable aspects of home gardening, but it is also one of the most misunderstood. Misuse of water in the home garden often causes more problems than it solves. Problems such as soil crusting, poor root growth, blossom drop, fruit cracking, nutrient deficiencies, and various types of diseases can be directly related to improper watering. tion, as water will flow quickly to the lower end of the garden. With this watering method, the water should be applied slowly and allowed to soak the soil thoroughly. Furrow or flood watering is probably the best method for most home gardens. Watering by this method can be selective in that only vegetables which require water can be watered. Watering with a furrow system eliminates soaking the top of the bed, which often results in poor soil aeration, disease problems, and weed growth. Also, small furrow systems can be arranged so that only one or two moves of the hose will water the entire garden. Sufficient water should be applied to wet garden soil to a depth of 4 to 6 inches. Frequency of watering will depend on climatic conditions, rate of growth, and stage of maturity of the plant. In general, additional water should be applied when the soil is becoming dry about 1 inch below the surface. SPRINKLER IRRIGATION Following is a brief discussion of the various watering methods available to home gardeners. FLOODING OR FURROW IRRIGATION Flooding or furrow irrigating the garden is probably the most common method. No specialized equipment is necessary other than some method of moving the water to the garden area-- usually a common garden hose. For this type of watering system to be most effective, it is best to have the garden bedded. Plants or seeds are planted on raised beds, and water is allowed to flow between the beds. The garden should be gently sloped, to facilitate the movement of water down the rows. Too steep a slope will result in poor water distribu- Watering with a sprinkler is probably the most convenient method. It is a simple matter to place the lawn sprinkler where it can water the entire garden. Overhead watering can be effective when properly used. With sprinklers, at least 1 inch of water should be applied with each watering. This can be determined by placing a coffee can in the path of the sprinkler and catching an inch of water. The water should be applied early enough in the day to allow the plant foliage to dry before night. Wet foliage, in combination with cooler night temperatures, often results in various types of foliage diseases. One serious disadvantage to overhead watering is that the application of water is indiscriminate. This results in water being applied to crops which do not necessarily need watering at that specific time. In general, sprinkler watering is best suited to cool-season crops, such as cabbage, lettuce, carrots, and broccoli. 2

3 Watering the Garden (Continued from Page 2) DRIP OR TRICKLE IRRIGATION Accent the Fall Landscape WITH Vegetables and Herbs Dr. William C. Welch, Landscape Horticulturist Drip or trickle irrigation of home gardens is a relatively new concept. This system is especially good for areas of Texas with limited water supplies or dry growing conditions. A drip or trickle system literally drips water onto the soil surface without disturbing the soil structure, so that the water seeps slowly into the soil. The water is dripped onto the ground through some type of emitter located adjacent to the garden plants. This method of watering is much more efficient than either furrow or overhead watering, in that the amount of water applied is usually about equal to the amount of water used by the plants since the last irrigation. Many drip systems are operated on an almost daily basis. Drip irrigation, when properly used, does not store water in the soil for future use, but replaces water that has already been used by the garden plant. There are many types of drip or trickle systems available, including Dew-Hose, Viaflow, Twin-Wall, Drip-Eze, and others. None of the systems is foolproof, and problems can occur in regulation of water pressure, clogging of emitters, or mechanical breakdown of the hoses or emitters. The systems are relatively expensive, but since they use water efficiently and economically, drip or trickle systems can pay for themselves within a short time. LANDSCAPE DESIGN STUDY COURSE II SEPTEMBER COLLEGE STATION, TEXAS Contact the Extension Horticulture Office for registration form and program: (409) Now is an excellent time to evaluate the home landscape and begin making preparations for fall plantings. Vegetables and herbs can be used in imaginative ways to add beauty, interest, and utility to our landscapes. Midsummer and early fall offer us a good 'second season' for growing these plants if gardeners can motivate themselves to provide a little extra care during the long, hot days of late summer. Hanging containers of parsley, mint, thyme, rosemary, and tomatoes can all be started now. These plants may be available at local nurseries, but with a little extra effort they can be grown from seed. Each has a drooping growth habit which makes it especially appropriate for hanging-container use. An even larger variety of herbs and vegetables may be grown in the more 'down-to-earth' containers, such as clay pots and wooden tubs. Tomatoes, peppers, lettuce, eggplants, carrots, and radishes are just a few of the many. Even small porches and decks of apartments can be made more attractive and interesting with groupings of containers filled with herbs and vegetables. Two important points to consider in growing container plants are the media and the container selection. Most vegetables require excellent drainage, so select a container with a hole in the bottom. Plain clay pottery is attractive and versatile, as are many of the cedar and redwood tubs. Small containers dry out very quickly, and sometimes require daily or twice-daily irrigation. A minimum size for containers is 10 to 12 inches, with 16 or 18 inches being more appropriate for large plants such as tomatoes or eggplants. The media must also drain well for most plants to thrive and yet still hold an adequate amount of water. Some gardeners prefer soilless mixes, such as half peat moss and half vermiculite. Others like the added support of micronutrients found in mixes such as one-third garden loam, onethird peat moss, and one-third sharp sand. Many different media can be used successfully. The most important factor is for the gardener to learn how to manage the media selected, since water and fertilizer requirements vary considerably. 3

4 Pre-Vacation Planning Pays Ted Fisher, Travis County Extension Horticulturist, Austin, Texas Now that summer has arrived, you may be thinking about taking that well-earned vacation. If you are planning to take an extended trip now or later this summer, be sure your landscape is in order prior to leaving. Lawns, gardens, and landscapes left unattended for several weeks can be ruined by our summer sun, wind, and heat. Just a little extra effort on your part before leaving can make a big difference in the health and well-being of your plants. Here are some practical tips that should help ensure that your home landscape will not suffer the post-vacation blues. WATER. Water the home grounds well prior to leaving. Soak your lawn, gardens, and all landscape plants deeply. Our shallow soils can dry out rapidly even after heavy watering, so if you will be gone over a week, plan to have a neighbor hook up your hose and do a little supplemental watering. CUT. Mow your lawn a day or two before your leave. Use the same cutting height that you normally do. Don't lower the mower blade for a 'closer shave'. Doing so could easily cause sun scald and damage. If you plan to be gone more than a week, it would be a good idea to arrange to have a friend or neighbor mow the lawn for you. Prune hedges and other plants likely to get gangly by the time you return. CHECK FOR INSECTS AND DISEASES. Spray, if necessary, for insects and diseases to prevent a buildup of pests during your absence. Summer insects and diseases do not take a vacation, and will work overtime on your healthy plants. This goes particularly for chinch bugs. Make sure you have applied chinch bug control to your St. Augustine lawn, or you just might find it severely damaged by this little critter when you return. HARVEST. Pick all ripe or nearly ripe fruit and vegetables. If you will be gone over a week, arrange for a friend to pull and use produce. Vegetables left unpicked will frequently cease to bear. MAINTAIN EQUIPMENT. Take lawn and garden equipment by the repair shop if needed. They will have it ready by the time you return. Be sure that walks and flower beds are neatly edged before your departure. A buildup of growth while you are away will be difficult to manage on your return. MULCH. Mulching helps conserve valuable moisture needed for plant growth while you are at home or away. Choose a clean mulch, free of weed seed, and one which will remain loose and well aerated. Consider grass clippings, pine bark, compost, or a variety of other organic materials. Mulching will also reduce or eliminate the weeding problem. PROTECT PROPERTY. Arrange for a neighbor to pick up newspapers, or ask the paper delivery service to hold them until you return. Newspapers scattered over the front lawn are a dead giveaway that no one is home. Lights on a timer are a good idea, and can provide an impression that someone is home. Have a nice trip knowing that things at home will be in fine shape when you return. And don't forget to visit some gardens while you are away. There are many spectacular gardens to enjoy in just about any part of the country where you may be headed. Landscape preparation for a summer vacation may sound like a lot of extra work, but it is really not much more than the normal weekend routine of maintaining a healthy, well-groomed landscape. 4

5 Rosemary Adds Interest To Texas Gardens Dr. William C. Welch, Landscape Horticulturist Many landscape plants suffer during the dry heat of August, but rosemary (Rosmarinus officinalis) thrives on it. Although usually cold-hardy in South Texas, some winter protection may be needed elsewhere in the state. Rosemary grows well even in poor, dry, rocky soil as long as drainage is good. The evergreen character of the narrow foliage and many horticultural forms of the plant make it quite useful. Prostrate selections are good for ground cover or spilling over retaining walls. Mature height ranges from 18 inches to 4 feet, depending on the variety and growing conditions. Small lavender-blue flowers in spring and summer are attractive but not spectacular. A major attraction of rosemary is the strongly scented foliage which is popular, fresh or dried, for seasoning. The fresh tops are reported to be used to distill the aromatic oil used in perfumery and medicine. Rosemary has been a popular plant for centuries in Europe, and was often planted close to the entrance of homes in the traditional cottage gardens of England. When people passed by and brushed against a rosemary plant, the scent was released and enjoyed. Rosmarinus officinalis is a native of the Mediterranean region. Typical of many plants in that part of the world, old specimens may be thinned to expose the gnarled stems, which create a bonsai-like effect. Few herbs can compete with this plant for landscape value. Propagation is by seed or cuttings. With the renewed interest in herbs, many garden centers now stock rosemary. One-gallon-size plants establish quickly. Full sun or partial shade are both good exposures. The key to successfully growing R. officinalis is well drained soil. If your soil is not well drained, try growing the plant in a clay pot or whiskey barrel half. Recently, interest in trimming rosemary into various topiary forms has increased. Tree standards are particularly nice. 'Arp' is probably the most cold-hardy selection of rosemary. onsumers are worried about the safety of pesticides used on our foods, and a majority believe pesticides pose a serious health hazard. However, pesticides are a useful tool that growers need to help insure quality produce at an economical price. Even with the use of pesticides, about one-third of the world's crops are destroyed each year by pests and diseases. Pesticides improve food quality, safety, and availability by reducing damage caused by insects, diseases, and weeds. Products damaged by insects are more prone to bacterial or fungal infection, and certain molds that can invade crops produce toxins that may be poisonous and/or carcinogenic in small quantities. The Environmental Protection Agency (EPA) is responsible for setting tolerances for any approved pesticide. Testing for pesticide residues in our food products is the responsibility of the Food and Drug Administration (FDA) and certain state health and agriculture departments. Data from the FDA and 42 state programs show that there are no detectable residues on 70 to 80 percent of crops tested; 20 to 30 percent have residues under recommended tolerances, and 2 to 3 percent contain residues of a pesticide not cleared for that crop. Besides eating a wide variety of healthful foods in moderation, there are several things a consumer can do to ensure food safety. Are they really necessary? Wash all fruits and vegetables in water (no soap) before eating, using a scrub brush on produce that can stand it (such as potatoes). Pull off the outer leaves of vegetables such as lettuce and cabbage. For the same reason, trim the leaves and tops of celery, and peel fruits. Store fruits and vegetables at correct temperatures, and eat them while they are fresh. When using pesticides on homegrown produce, be sure to follow all manufacturers' instructions carefully. Taken from an article by Dr. Al Wagner, Professor and Extension Specialist, Department of Horticultural Sciences, and Dr. Charles Hall, Associate Professor and Extension Specialist, Department of Agricultural Economics, Texas A&M University, College Station, Texas 5

6 Fertilizing Vegetables Dr. Jerry M. Parsons, Professor and Extension Specialist, Department of Horticultural Sciences, Texas A&M University, San Antonio, Texas You don't fuel a Jaguar with kerosene. You don't adjust a computer with a monkey wrench. High-performance items require extraordinary care and special consideration. The same is true of vegetable varieties and grass. The varieties recommended by Extension are the first high-performance types ever introduced into this market. If they are treated badly, they will produce badly. If they are pampered and 'souped up', they will be magnificent. What is abuse of a higher-performance vegetable variety? The answer is lack of consistent, persistent care. Consistency of care for a high-performance variety involves a program of regular fertilization (every 3 weeks with ammonium sulfate ), preventive fungicide sprays (maneb or chlorothalonil products, such as Ortho Multipurpose Fungicide or Fertiloam Broad Spectrum Fungicide) every 7 to 10 days to avoid foliage damage and/or loss, insect control when needed, and, in the case of tomatoes, support of vines off of the ground in wiremesh cages. All of these cultural practices must be persistently adhered to if maximum production is expected. Of all requirements mentioned, the most neglected is the lack of a periodic fertilization schedule. It has often been said that the Surefire tomato is specifically adapted to heavily manured gardens; the Summer Sweet 860 bell peppers are consistently larger and four-lobed in heavily manured gardens; and the largest onion bulbs ever grown were in a soil mixture of almost pure, well-decomposed manure. This is not a difficult phenomenon to understand when we realize that manure is the original slow-release fertilizer. Manure consistently feeds plants. Most gardeners accept that 2 pounds of a slow-release fertilizer, such as , should be added to 100 square feet of garden area before planting, but very few realize that additional plant food is required on a regular basis if maximum yields are to be expected. Maximum yield insurance is called side dressing. The term 'side dressing' simply indicates an application of fertilizer, usually one containing nitrogen only, alongside the rows or in a circle around growing plants. This will insure a supply of nitrogen as the plant grows and develops, and is particularly helpful in sandy soils or in seasons of abundant rainfall, as nitrogen has a bad habit of being washed or leached out of the root zone. Side dress with a nitrogenonly fertilizer, such as ammonium sulfate , during the growing season, and water in. Ammonium sulfate is best because it is very effective, readily available, and relatively inexpensive, plus, it helps, at least slightly, to acidify our alkaline soils. Thus, side dressing offers 3 very important advantages: properly used, it helps prevent the delayed fruit-set caused by excessive nitrogen too early in the season; it significantly increases yields; and it results in healthier, stronger plants with fewer pest problems. The rate and timing of side dressing applications is important. Unless otherwise specified, one-half cup of ammonium sulfate per 10 feet of row is adequate for most crops. Information about the best time to side dress some specific crops is outlined below: Beans, snap, wax, lima: after plants flower and set first fruit. Okra: 3 weeks after harvesting begins. Onions: when 5 to 6 leaves are formed. Potatoes: when 6 to 8 inches tall. Sweet potatoes: in June. Sweet corn: when 8 to 12 inches tall, at a rate of 1 cup of fertilizer per 10 feet of row. Tomatoes, peppers, eggplants: when first fruits are marble-sized, at a rate of 1 level tablespoon per plant -- repeat every 4 weeks. Vine crops, cantaloupe, cucumber, watermelon, squash, pumpkin: when vines are 1 foot long, at a rate of 1 level tablespoon per plant. Whenever side dressing, avoid getting the fertilizer particles on the plant foliage, and always water in thoroughly after application. Do not dump the fertilizer on the base of the plant, but instead, evenly distribute it several inches away from the base. This principle of moderate but more frequent applications of fertilizer will also work wonders for your flowers and for your new landscape plants during their first 3 seasons of growth. So, if you plant to grow high-performance vegetable hybrids, grow them right or don't grow them at all! 6

7 Garden Checklist for July / August Dr. William C. Welch, Landscape Horticulturist Caladiums require plenty of water at this time of year if they are to remain lush and active until fall. Fertilize with at the rate of one-third to one-half pound per 100 square feet of bed area, and water thoroughly. Prune out dead or diseased wood from trees and shrubs. Hold off on major pruning from now until midwinter. Severe pruning at this time will only stimulate tender new growth prior to frost. Sow seeds of snapdragons, dianthus, pansies, calendulas, and other cool-season flowers in flats, or in well-prepared areas of the garden, for planting outside during mid-to-late fall. Plant bluebonnet and other spring wildflowers. They must germinate in late summer or early fall, develop good root systems, and be ready to grow in spring when the weather warms. Plant seed in well-prepared soil, one-half inch deep, and water thoroughly. Picking flowers frequently encourages most annuals and perennials to flower even more abundantly. It is time to divide spring-flowering perennials, such as iris, Shasta daisy, oxeye, gaillardia, cannas, day lilies, violets, liriope, and ajuga. Make your selections and place your order for spring-flowering bulbs now so that they will arrive in time for planting in October and November. Don't allow plants with green fruit or berries to suffer from lack of moisture. A late-summer pruning of rosebushes can be beneficial. Prune out dead canes and any weak, brushy growth. Cut back tall, vigorous bushes to about 30 inches. After pruning, apply fertilizer, and water thoroughly. If a preventive disease-control program has been maintained, your rose bushes should be ready to provide an excellent crop of flowers this fall. It is not too late to set out another planting of many warm-season annuals, such as marigolds, zinnias, and periwinkles. They will require extra attention for the first few weeks, but should provide you with color during late September, October, and November. Establish a new compost pile to accommodate the fall leaf accumulation. Texas & Southwest Greenhouse Growers Conference November 11-14, 1997 Hilton Hotel & Conference Center College Station, Texas Call (409) for information 7

8 Texas Agricultural Extension Service United States Department of Agriculture The Texas A&M University System College Station, TX BULK RATE POSTAGE & FEES PAID USDA PERMIT NO. G-268 OFFICIAL BUSINESS Penalty for Private Use $300 FORWARD AND ADDRESS CORRECTION JULY / AUGUST 1997 In this issue... Plant of the Month: Bachelor Button... Page 1 Watering the Garden... Page 2 Accent the Fall Landscape with Vegetables and Herbs... Page 3 Pre-Vacation Planning Pays... Page 4 Rosemary Adds Interest to Texas Gardens... Page 5 Pesticides: Are They Really Necessary?... Page 5 Fertilizing Vegetables... Page 6 Garden Checklist for July / August... Page 7 Horticultural Update is published by Extension Horticulture, Texas Agricultural Extension Service, The Texas A&M University System, College Station, TX CONTRIBUTING EDITORS: Drs. Samuel D. Cotner, Vegetables; George F. McEachern, Pecans & Grapes; William C. Welch, Landscape; Douglas F. Welsh, Landscape EDITOR JULY / AUGUST 1997 Douglas F. Welsh Landscape Horticulturist