Sunday, September 23, 2007

GREEN THUMBRoses Part 2- Pruning, caring for and protecting Rose plants!



By ARUN PRATAP SINGH
Last week, we discussed about selection of Rose cultivars suitable for various uses and locations. We also discussed how to plant them, how to grow and prune them. Growing rose plants is not very easy but a very rewarding hobby nevertheless. Rose plants must be fed carefully and protected from various pests and diseases as they are vulnerable to a number of pathogens and diseases. Here we shall dwell on the maintenance, feeding and protection of Rose plants.
Feeding: Though, feeding of Rose plants was discussed last week too in some detail, it is essential that we know more about feeding requirements of Rose plants. For example, it is essential to remember not to fertilise newly planted roses at least for two months. Rainfall is heaviest during the monsoon months. Heavy rains during this period leach fertilisers from the soil and interfere with soil aeration, causing plants to drop older leaves. The three basic nutrients for health growth of any plant Nitrogen, Phosphorous and Potassium are needed in balanced applications. If one desires to avoid chemical fertilisers, one can try a mixture of Mustard or Neem Cake, Bone meal, compost, cattle dung manure. A commercial fertiliser should be applied to Rose plantings 5 to 7 times a year (each time plants produce a flush of bloom).A formula found suitable for Uttarakhand was mentioned last week. Another alternative formula suitable for this region can also be used. A complex mix of chemical and organic mixture has been tried by the columnist with good success here. Alternatively one can try a complex mix of chemical and organic fertilisers. Mix 1 kg Ammonium Sulphate (or Urea), 2 kg Single Super Phosphate, Potassium sulphate (or MOP) 1 kg, 5 kg of pulverised Neem, Mustard or Groundnut cake, 3 kg. Sterilised Bone meal, Wood ash or crushed wood charcoal 2 kg, Iron Sulphate 250 gm, Magnesium Sulphate 200 gm, Soil Agromin 300 gm. About 125 gm of this powder can be used @ per sq mt. or three spoons per pot. Foliar spray or liquid feeding is also useful. For this it is better to use some compound fertiliser like Polyfeed or Nitrophoska @ 3 gm/litre for spray or @ 5 gm/litre for liquid feed given in form of fertigation. Remember to water thoroughly immediately after the fertiliser application.Watering: The amount and frequency of application depends on soil type, bush size, and the rainfall in your area. When watering roses, be sure to soak the soil well as they need more than just light sprays of water. It is useful to wash off their leaves every week or so to remove the dust particles. Accumulation of water soluble salts in root area and the resulting injury to roots is prevented by thorough irrigation. Roses should be irrigated with one inch of water once each week unless a similar amount of rain falls. In simple words, that would mean good watering twice a week. However, in May and June, one may need to water the rose plants even more frequently. Potted rose plants need to be watered and fertilised more often. In summer months, daily watering may be required in case of potted rose plants.
PRUNING AND GROOMING
Pruning should be done once each year during Third Week of September in Doon Valley and regions like Almora and Haldwani. In the plains of Haridwar, Rishikesh and Udham Singh Nagar it must however be done during mid-October. In Mussoorie and the rest of the hills, it must be done in late January during the dormancy. Major yearly pruning consists of removing some healthy top growth as well as twigs and branches that are dead, diseased, injured, unsightly or thin and spindly. Shortening main canes and lateral branches, removing small twigs and some of the oldest canes improves the plant’s form. It also regulates height and produces better light conditions within the plant. Leave at least half the length of each main cane that is one to three years old. The first flowers can be expected eight to nine weeks after pruning. To avoid dieback and encourage rapid healing, pruning cuts should be made just above a dormant bud (eye). When an entire branch is removed, make a smooth cut at the point of juncture. Flower buds should be removed for the first two months after planting to encourage growth and help to establish a new plant. Plants should be well established before flowers are cut with longer stems, and then only cut the length of stem needed. Remove suckers (leafy shoots) that develop from the rootstock below the graft union by breaking them off rather than by cutting in order to remove all basal buds. Rootstock suckers can be recognized by their location and their different leaf appearance. Remove dead wood and canes showing stem disease symptoms when they are first noticed. Cut the affected part back to healthy wood and remove the affected part from the garden area.
PROTECTION
Many pests and fungal diseases afflict the roses. Black-spot, Powdery and Rust are three most common diseases afflicting the rose plants in India. Pests can also cause problems for the plants. Aphids, Thrips, Beetles, Borers, Rose midge, caterpillars and worms, Mites are some of the more troublesome Rose pests.
PESTS
Aphids: Probably the most commons pests in a rose garden are Aphids. They are tiny green bugs. They like the tender leaves and the new buds. They get into groups and suck the rose juices. Spray Malathion or Fenvalerate @ 2 ml/litre of water.
Thrips: They are little bugs that one can hardly see them. They affect the flower buds killing them before they open or just as they open. Spray Malathion or Fenvelerate @ 2 ml/litre of water.
Caterpillars: They don’t do that much damage to the flowers, but they do damage to the leaves. However, they chew the leaves and can damage the plants. Spray Fenvalerate @ 3 ml/litre of water or Cypermethrin 10 @ 3 ml/litre.
Spider Mites: They are tiny spiders (not real spiders, though) that concentrate on the leaves. They cover them with a little spider web and soon the leaves have orange spots. They are not related to common spiders. For treatment spray Phosmite or Quinalphos @ 2 ml/litre twice at ten days interval.
Red Scale: This is a serious pest on the rose plants. The branches get covered with reddish brown crusts under which the insects suck the juice of the plants. To control, spray the plants in Malathion and Rogor @ 3 ml/litre of water twice in April and then in October.
DISEASES
Diseases are caused by fungal attack.
Black Spot: They are bad in warm, humid weather. They attack wet leaves. Don’t water at night and keep good air circulation. Spray the plant with systemic fungicide like Carbendazim (Bavistin) @ 3 gm/litre or Thiophonate Methyl (Topsin) @ 2 gm per litre of water twice at seven days interval.
Powdery Mildew: It’s that white powder on the leaves. Like any other fungus, it’s more frequent in humid areas. Keep good air circulation around your plants and keep the leaves dry. For control, spray the plants with Dithane M-45 @ 3 gm/litre of water. Repeat the pray at least once more @ ten days interval.
Die-back: When a stem turns black, you have Die-back. This normally appears after the pruning. Remove that stem cane as soon as possible before it has a chance to spread. Don’t forget to clean your pruning tools with alcohol after that. Spray the plants with a systemic and contact fungicide like Bavistin @ 3 gm/litre.

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