Hi, I planted a "New Dawn" climbing rose last May. It has put up one climbing shoot and the bottom leaves are turning yellow. It is not thriving here in Wainuiomata. I am from Canterbury and have grown many roses with few problems. This one does not look well. Any advice would be greatly appreciated. Ken Baird

Hi Ken, roses like a free draining soil that is rich in organic matter and a soil pH of 6.5 - 7, they don't do well in heavy clay or light sandy soils. It may pay to test your soil pH, it could be that the soil is too alkaline (high pH), roses prefer slightly acid (lower pH) soil conditions. You can test soil pH at home by purchasing an inexpensive soil pH meter or soil test kit from a hardware store or garden centre. To change the soil pH, if it is higher than 7, add sulphate of iron or flowers of sulphur, also add generous amounts of compost or mulch to improve the organic content of the soil, each season keep adding organic matter to the soil. If it is the opposite, apply lime to bring the soil back to a more neutral pH, adjusting soil pH is a slow process and takes time. It is always better to feed roses with a balanced fertiliser such as Tui Rose food, which contains iron and sulphur, as well as nitrogen for healthy leaf growth, phosphorus for a strong root system and potassium to promote flowering, as well as trace elements to correct soil deficiencies. The other possibility is that the rose is suffering from lack of water and has dried out at some stage, they do better with deep watering, rather than light sprinkles. Mulch around roses with pea straw or Tui Mulch & Feed, this helps conserve soil moisture. Also keep an eye out for diseases such as rust or black spot, they can be prevalent late in the season, remove infected leaves from the plant and the soil to prevent disease spreading, your local garden centre will be able to recommend a suitable fungicide for disease control. Lianne.