SELECTING A PLACE TO PLANT YOUR ROSES:
Try to pick a place where there will be sun for at least 6 hours of the day, not too near large trees or hedges. If you can find an area with morning sun and afternoon shade with will be preferable. Houston roses do well in full sun with good air circulation.
PREPARATION OF HOUSTON ROSE BEDS:
Your typical rose bed requires a single row of roses with 18” on each side for a total of 3’ feet. A double row needs five feet. For convenience, it is preferable to have no more than two rows to allow at least four feet between beds. Proper soil preparation will by very beneficial for rose production. Houston area soil is primarily heavy black clay (gumbo) and is slightly alkaline. Roses prefer a slightly acid soil. Rose beds should be elevated above yard level for good drainage. You can build up the bed using wood, steel, brick or stone to enhance drainage.
An ideal mixture consists of 1/3 loam or soil, 1/3 sand, and 1/3 organic matter. For a rose bed of approximately 100 square feet, add 20 pounds of Superphosphate (0-20-0) and 20 pounds of agricultural gypsum. A rotary tiller makes the job easier and allows new beds to settle and compost for a few weeks before planting. Good sources of organic material are pine bark, leaf composts, composted manures, peat moss or a combination of these materials.
The best time to plant bare root roses in Houston is during January and February. Potted roses can be planted throughout the year. Transplanting is best done when bushes are dormant. Select good quality rose bushes that have not dried out in storage or shipment. Dried out plants will not start or produce well. Store bare root roses in a cool place, and keep moist if they are not to be planted immediately. Soak roots briefly before planting. Dig a hole about 12 inches deep in a prepared bed, forming a cone in the planting area to support the roots. Place the bush over the soil cone so the bud union (where the rose is grafted to the roots) is two or three inches above the soil level of the bed. Cover the roots with soil removed from the planting area and water in thoroughly. After settling has occurred, finish filling the bed, and mound additional soil over the bud union and several inches of rose canes to conserve moisture. After new growth has started, carefully pull back excess soil so that the bud union is exposed to sunshine. This will encourage additional new canes from the bud union and result in a more-productive bush.
Houston roses, and the surrounding gulf coast area, require at least one inch of water per week. More is required during periods of hot, dry weather. Water thoroughly and deeply about twice each week. Slow soaking is best and avoid getting too much water the leaves.
Roses are heavy feeders and thrive on regular, light feedings. Begin a feeding program when new growth begins in the Spring and continue every 4 to 6 weeks during the growing season. Composted manure is good and many commercial fertilizers do a good job. Special rose foods are also available. Follow the directions carefully. DO NOT overfeed. Light, regular feedings are the most effective. WATER thoroughly before and after feeding. Water is essential in the feeding process.
The principle insects that attack Houston roses are aphids and thrips. Aphids (plant lice) are sucking insects that damage new growth. Thrips bruise and discolor blooms, particularly lighter colors. Several insecticides provide effective, safe control. Mavrik, Orthene and Malathion are popular in Houston. Follow product directions carefully. Use only when infestations are obvious. Spray only after rose beds have been thoroughly watered. Early morning or late evening spraying is best to avoid leaf burn. Red spider mites sometimes occur during hot dry weather. These tiny insects multiply on the underside of leaves, resulting in loss of color and, final a loss of leaves. Infestation occurs on the lower leaves and gradually work their way up. A strong water spray on the underside of leaves, washing away the insects and webbing, every other day for a week will usually bring control.
FUNGUS DISEASE CONTROL:
Blackspot disease is the major enemy of Houston roses. Black spots appear on leaves, gradually spreading as leaves turn yellow and drop off. Blackspot greatly weakens the bush and retards growth. Blackspot can be prevented through regular use of a fungicide. These products are readily available, safe and easy to use. Begin a preventative program when leaves first appear, and continue every week during the growing season. Humid, warm weather encourages blackspot; dry periods do not require as much control. Spray a fungicide on a regular schedule, wetting the leaves, top and bottom. Powdery mildew most often occurs in early Spring or late Fall with cool nights and warm days. Mildew appears as a gray white mold on new leaves and stems. It spreads rapidly if moist conditions persist. If mildew appears, spray twice a week until control is established and new growth is free of disease.
Houston roses are best when pruned in the springtime to encourage new growth and development. Cut out dead or nonproductive wood, flush with the bud union. Trim out twiggy growth. Trim back canes from the previous year to about 24 inches. Trimming maintains size and shape of bush. Prune during the month of February. Repeat climbers should be pruned while dormant; rambler and once-blooming climbers should be pruned AFTER flowering.
For additional information on planting Houston roses contact us, or visit Exterior Worlds.