- Look for a strong bud union and healthy canes. Remember that it takes two to three years, for your rose to grow into a good flowering plant.
- Make sure your rose bush is not smothered and that it has plenty of air movement so it develops a tough leaf. Remove all leaves that drop [and prunings from around the plant] - these may harbour spores that could reinfect. My golden rule is to spray regularly, to spray prior to rain and again the day the rain stops.
- A winter spray programme will provide a good base for the start of a new season. Alternate your sprays so that disease resistance doesn't become a problem.
- Spray in fine, but dull and wind free weather conditions ensuring that there is plenty of drying time. If rain washes your spray off then you will have to reapply it. Sometimes a spray at this time is better than nothing.
Spring (September to November)
The first leaves of the season are delicate and can be susceptible to infection due to the climatic conditions of Spring. From leaf burst apply Gild or Shield and alternate them at approx 14 day intervals. These are good sprays for general use.
Gild and Shield are systemic sprays that control both fungal and insect problems. Downy mildew can also be a problem in Spring and Autumn and appears as purple blotches on the upper leaf surface and a mildew appearance on the underside of the leaf. This can be prevalent in cool moist conditions and good air cirulation will help - this means preventing plants growing too close to your roses. Bravo can be alternated with various products - I recommend using Gild, Shield or Super Shield. Spray 14 days apart and alternate. However, if my roses get an infection then I spray closer together than 14 days, to bring it under control. Bear in mind with timing that if rain is imminent it is better to spray the roses than to leave them. Constant deheading will keep your roses in bloom over this time.
If you want your roses in flower for a particular event, then cut them back approx seven to eight weeks prior and feed and water them well.
Summer (December to February)
This is the time of year that people tend to get lazy: holidays are more important and spraying tends to cease. It is important if you want good looking plants going into the Autumn for flowering that you maintain some of your programme. If you don't, then the plants tend to defoliate due to disease. I tend to let my spraying frequency lengthen but I keep it going over the season.
Powdery mildew and mites tend to be the problems through the Summer. Keep up with Sprays of Gild, Shield, Super Shield and or Bravo, Mites are a real nuisance and the sprays to control them are quite toxic. However, you can use Spraying oil at summer rates which will help, and I have been using an insecticide called Mavrik which contols both Mites and Aphids.
Remember to feed your roses with an artificial fertilizer during mid February for the Autumn flowering flush.
Spray for rust when you notice it, with Mancozeb or Yates All Purpose Rose Spray.
Maintain deep waterings to keep your roses flowering through this time.
A good deheading (early Feb) will promote an Autumn flush of blooms. Remember, as a rough guide, it takes about 8 weeks (depending on the season) from the time of deheading before the next crop of flowers.
Autumn (March to May)
The slower time of year. Basically keep up with your Gild and alternate sprays at what I would call 'rest' frequencies - in the home garden you should be able to stretch this out to perhaps 3 weeks if conditions are good.
Don't dehead during this period, as when your roses have finished their Autumn flowering you want them to set hips.
Winter (June to August)
The winter clean up time. By doing a good spraying effort here with the safer sprays of Copper, Oil and Lime Sulphur you will get your roses off to a really good start for the Spring.
When such time comes that you think the roses should have finished flowering (around April going into May), start with Copper oxychloride. This will harden the leaves and help force them to drop. It is important to pick these leaves up and burn or dispose of them in your rubbish collection. 2 or 3 sprays of copper at a week to 14 days apart should be enough to help your roses into Winter retirement.
Wait for two weeks after the last copper spray - this is important as Copper is incompatible with Lime Sulphur. Spray a Lime Sulphur spray and then two weeks later, spray again. Lime Sulphur has quite a distinctive smell and will stain your house, so be warned.
Two weeks later spray again with Copper Oxycloride and Spraying Oil.
You are now ready to prune. Follow pruning with another Copper and Oil spay and perhaps another in two weeks time. Make sure the spray gets into all the crevices of the rose and it is a good idea to spray the surrounding ground. Prune your roses late June to Early August.
Finally, during mid to late August, feed your roses with artificial fertilizer for their Spring flowering.
And most importantly, make sure you take the time to enjoy the rose.
Wairere Nursery 826 Gordonton Road, R D 1, Hamilton Ph: (07) 824 3430 Email: Open 7 days 8:30am-5pm