Welcome to your handy symptoms, diagnosis and treatment for all your rose problems!

Planting for health
• Avoid planting beneath trees as roses do not like competition from tree roots or shade.
• Avoid planting in saturated or boggy soils or after heavy rainfall.
• Avoid adding manures or fertilisers in the planting hole — new feeding roots will be damaged if they make contact with these materials at planting time.
• Avoid planting too closely, as roses that get tangled into each other are harder to prune and more susceptible to fungal disease.
• Avoid tying climber and standard roses too tightly. Figure of 8 loose ties are best.
• Avoid overhead watering and watering during the hottest part of the day as this will promote leaf fungal diseases.
• Avoid using chemical fertilisers until the plants are in full leaf as this will burn young roots. We like organic fertilisers which can be used anytime, enrich the soils and feed our plants.
Rose care calendar
We’re keen advocates of the “prevention is better than cure” regime for roses. Here is our annual program for optimal rose health.

Water: Once a week give a full watering can and seaweed solution to the root systems of every rose.
Spray: Every second week spray with Yates Rose Shield plus seaweed solution (Plant Health Spray). Alternate every second week with eco oil plus eco rose.
Feed: Every six weeks with organic pelleted rose food.

Water: Twice a week give a full watering can and seaweed solution to the root systems of every rose.
Spray: Every week with Yates Rose Shield plus seaweed solution (Plant Health Spray). Alternate every week with eco oil plus eco rose.
Feed: Every six weeks with organic pelleted rose food.
Prune: Trim by one-third to encourage a better autumn flush.
Water: Once a week give a full watering can and seaweed solution to the root systems of every rose.
Spray: Every week with Yates Rose Shield plus seaweed solution (Plant Health Spray). Alternate every week with eco oil plus eco rose.
Feed: Every six weeks with organic pelleted rose food.

Water: No watering.
Spray: Lime sulphur spray is useful in reducing the population of insects, disease, fungal spores and insect eggs, disinfecting the rose and giving it a fresh start for the coming spring season. This must be done onto bare stems, not on leaves, so is a job for just after the winter prune.
Prune: Winter prune in late July-August, depending on where you live. Tidy up climbing roses.
Feed: Fertiliser is unnecessary, but you can condition the soil around your rose with seaweed (actual seaweed, seaweed granules or pellets such as Seamungus).
Other jobs: Check ties on standard roses and climbers so they aren’t ringbarking the stems.
Look out for…
Old garden roses – China
A Swiss botanist found Rosa chinensis mutablilis growing at Isola Bella, Lake Maggiore in Italy in 1934, and from there it spread through European gardens. It grows into a large spreading bush with butterfly-like flowers that open yellow and turn pink then crimson. We love its open-hearted flowers, tough nature and long flowering period.

Pests and Problems

Symptoms: Tiny green 1mm long insects gathering in numbers on new foliage and buds.
Diagnosis: Aphids are sap suckers that love the new growth and tender young buds of roses. They cause stems to wilt and can also cause problems by transmitting diseases from one plant to another. 
Treatment: Remove them with a gloved hand, or if you are squeamish, use a pyrethrum-based spray. Persistent infestations may require the use of stronger sprays such as Confidor or Mavrik. Use strictly in accordance with directions and follow safety precautions. 

Symptoms: A white mottled appearance on leaves, browning of petals and flower drop.
Diagnosis: Pale coloured roses can be affected by thrips. These tiny threadlike insects suck the sap from the flowers, and can also spread plant viruses. If left unchecked the leaves, new shoots and flowers will become deformed.
Treatment: Thrips lay eggs in unopened buds, making them difficult to control. They blow in on westerly winds and infest certain light-coloured roses, then pass on to other areas. New flushes of roses will be fine. 
Symptoms: White crusted stems.
Diagnosis: Scales are small, sap sucking insects with a hard cap which is hard to remove. Scales found on roses include cottony cushion scale, red scale and rose scale.
Treatment: Oil sprays such as Eco-oil or Pest Oil kill all stages of scale insects by suffocation and have a low impact on beneficial insects. Yates Lime Sulphur is also a useful tool in reducing the population of scale; spray onto bare stems after winter pruning. The best treatment is prevention – scale is only found on weak roses. 
Two-spotted mite
Symptoms: Tiny insects invisible to the naked eye, but seen as webbing and silvering of new growth.
Diagnosis: This insect was formerly called red spider mite, and is hard to control. It loves hot dry weather.
Treatment: Insecticidal potassium soap sprays such as Natrasoap work by blocking the breathing pores and dissolving the scale’s outer covering, causing dehydration. These treatments will not harm beneficial insects and have a very low toxicity to people and pets. The use of Mavrik should control this pest but in the case of severe infestation the use of predatory mites is helpful. Contact Integrated Pest Management, PO Box 436 Richmond NSW 2753. Yates Lime Sulphur is also a useful tool in reducing the population of two-spotted mite — spray onto bare stems after winter pruning. 
Symptoms: Flowers chewed.
Diagnosis: In dry times grasshoppers will eat flowers.
Treatment: Because grasshoppers move so quickly, they are impossible to control. 

Help! I have Black Spot on my roses

To the rose enthusiast the appearance of black spot can be an endless headache. However, with a few proactive health strategies for your roses, black spot needn’t darken your mood.

What is black spot?
Black spot is a fungal disease characterised by the appearance of circular spots over the foliage of affected roses. Black spots with yellow-fringed edges, up to 12mm across, will appear on the leaves of affected bushes. These affected leaves will eventually become yellow and fall off. If left untreated, black spot can cause a rose bush to completely defoliate, leaving frustrated gardeners scratching their heads over the demise of their favourite rose bush.

What causes black spot?
Black spot is caused by a fungus, which thrives in warm, humid conditions. It is more common in particular rose varieties, particularly those with yellow genetic parentage. 
The first yellow rose was introduced into rose breeding in Paris in the mid-19th century. This Persian rose, R. foetida ‘persiana’, which was most likely introduced by Andre DuPont, Empress Josephine’s rose-breeding confidante, went on to play a significant role in the development of new rose cultivars, creating never before seen colour variations. It is reported that with the introduction of R. foetida, the Empress’ collections at ‘Malmaison’ increased from 182 varieties, to over 6,000 between 1814 and 1850.
Sadly, over time R. foetida proved to be very susceptible to black spot. Today the susceptible gene is the bane of many frustrated rose growers worldwide. So prevalent was the Persian rose in breeding that many modern rose varieties, especially yellow varieties, are believed to have R. foetida ‘persiana’ as part of their ancient parentage.

Managing black spot on rose bushes
Controlling black spot in roses requires a multi-faceted approach. Rather than treating the symptoms in isolation, a holistic approach at managing the disease will yield better results.

1. Consider the weather conditions
Many fungal diseases proliferate in warm and wet conditions, particularly if the leaf remains wet for extended periods. Reduce humidity by avoiding overhead watering. Watering in the evening should also be avoided, as it allows moisture to remain on the foliage, creating ideal conditions for fungal spores to germinate and cause disease. Make sure there is good air circulation around your rose bushes. 

2. Select resistant rose varieties
As most roses are genetically susceptible to black spot it is important to choose resistant varieties that are well suited to your climate. 

3. Choose your planting location carefully
Growing conditions can play a big part in a plant’s susceptibility to pest and disease. Most roses require a minimum of five to six hours of direct sunlight each day to bloom properly, so it is best to avoid semi-shaded positions when planting.
Roses also prefer to grow without root competition from other plants, such as large trees. For example, if planted under large gum trees roses will compete for water and nutrients, making the plant even more prone to infestation. 

4. Maintain good plant hygiene
Good sanitation is important to eliminate contamination by fungal disease. Remove and dispose of diseased leaves, including those on the ground, and put them in the rubbish, not the compost. Leaves left lying on the soil have the potential to pass fungal spores on to other roses. Apply a layer of mulch prior to spring so that there can be no splashing of remaining fungal spores from the soil to the lower foliage of the plant. 

5. Keep your roses healthy
Just like humans, the healthier your roses, the stronger their resistance to black spot. By improving the general vigour of your rose plants with generous applications of a specific rose fertiliser that includes potash, as well as improving the growing conditions, you can reduce, if not overcome, the incidence of pests and diseases.

Suitable products for treating black spot
Members of the Rose Society of NSW, and other Australian rose societies, have conducted trials of the rose fertiliser, Sudden Impact for Roses, which consistently show an improvement in overall health of the roses trialled, with increased resistance to fungal disease, resulting in a significant reduction in preventative spraying; up to 66%.
Rose sprays with tau-fluvalinate and myclobutanil as the active ingredients (like in Yates Rose Gun, and Yates Rose Shield), will be effective in the control of black spot and insects such as thrips and aphids.
OCP Eco-Rose is effective in the control of black spot because it contains a specially formulated potassium bicarbonate that alters the pH of the leaf, dehydrating the fungal spores. It can also be combined with OCP Eco-Oil for further benefit.
It is good practice to spray roses after pruning in winter with lime sulphur, to disinfect them and clean up fungal spores and insect eggs. If untreated fungal spores can multiply over winter then germinate in spring in the warm, humid conditions.

Remember… prevention is better than a cure
High humidity combined with warm weather encourages black spot, so it is important to start treatment early. Start a program of preventative spraying every two weeks, beginning early in the growth season (October) and continuing through spring, summer and autumn (April).
Alternate each fortnight between Yates Rose Shield and a mixture of OCP Eco-Oil & Eco-Rose. A regular watering with a foliar seaweed tonic like Organix Ecoguard will increase the health and vigour of roses by thickening cell walls, making them inherently stronger.
Even with the best hygiene practices, if your roses become stressed for any reason they will get black spot. Healthy and well nourished plants grown in the appropriate environmental conditions are always naturally better equipped to fight off pests and diseases.

You can now listen to Linda Ross ‘Talking Gardens’ every day on Talking Lifestyle 2UE. She takes your questions and chats with friends and experts for a fun and fact-filled hour. Recently she explored the gorgeous world of orchid cactus, a favourite for easy hanging baskets with maximum impact. Tune in on weekdays from 12-1pm, or download the 2UE app on your smart phone and listen anywhere!
Call on 13 12 83 if you have a question.

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