Posted on: June 10th, 2019 by Stone Cross Garden Centre No Comments

Some common garden questions

Question: I have a rhododendron bush that has not flowered this year. Why is this?

Answer: For show breathtaking blooms there is little better than the Rhododendron! There are usually four reasons for their reluctance to flower.

  1. It may be an extremely young plant without the strength to flower.
  2. Whilst they like some shade, they also like some light. Too little shade can overheat the plant. To little light means that the plant can’t use the sunlight to produce energy
  3. Rhododendrons are acid loving and like a specialist ericaceous food. If you plant is producing lots of new leaves then there could be an excess of nitrogen in the soil. This makes the plant think you want it to grow bigger rather than flower.
  4. Watering and drainage. If a plant is saturated at the base of its roots it can be fatal. This often occurs when Rhododendron are planted in pots where the drainage holes are blocked. It is best to raise pots on pot feet to allow excess water to flow away. In addition if there is too little water in the autumn when the buds are setting they will not develop. Whilst the watering needs of other plants are decreasing in the autumn the Rhododendron and Camellia will require more in order to get the buds to swell.

Question: My Rhododendron has crinkly leaves. Is there any reason for his?

Answer: This occurs for two reasons. If exclusively on new softer growth it is likely the frost has caused the new leaves to pucker distorting them as they unfurl. The second cause is sap-sucking insects. These are at their worst when there is dry weather. They are found under the leaves where they suck the moisture from the leaf. This has the effect of making the leaf look this someone has tightened a draw string along the centre of the leaf. It can be treated by insecticicides.

Question: Why do my Rhododendron leaves have spots on them?

Answer:  There are a number of possible causes:

  • This is usually seen as a lot of orangey dots and even some black spots too on the leaf. It can be controlled with a fungicide.

Question: Why do my Rhododendron leaves look like they have had a slice of cake taken out of the side of them?

Answer:  This is a sign of the presence of vine weevil. These are nocturnal insects that are most dangerous when at the younger larvae stage. The adult vine weevil cause cosmetic damage to leaves so is not as damaging. Younger vine weevil, at the larvae stage, will eat the bark and roots of the plant. This is far more damaging. It can be treated by pouring a liquid vine weevil killing solution into the soil around the plants roots

  • This is usually seen as a lot of orangey dots and even some black spots too on the leaf. It can be controlled with a fungicide.

Question: My old Rhododendron bush has lichen growing on it. How do I get rid of this?

Answer: The lichen usually forms on the weak older stems of older overgrown bushes lacking in leaf. It is possible to remove the lichen by blasting it with water from a hosepipe. However, the lichen is often a sign that the plant has poor drainage and is lacking goodness in the soil. It is best addressed by pruning back the plant and applying a specifically formulated rhododendron fertiliser.

Question: I have a lot of ants in my garden is this a problem?

Answer: Ants can be an issue in gardens on occasions. In lawns they can make powdery nests but these can be brushed or mown away. The ants are often drawn into gardens to feed on the honeydew excreted by aphids. This is best treated by tackling the aphids. Ants generally cause little damage and are a beneficial part of the gardens ecosystem. However, should their presence become too much of an issue you can get rid of the ants by using Ant Killer Powder dusted on the surface of the ground. This does not tend to damage plants. There are also home remedies that have proved successful to gardeners such as pouring boiling water, sprinkling bonemeal, pouring vinegar and pouring washing up liquid. With all home remedies you should take extreme care as vinegar, for example, will result in the change in ph of the soil and potentially kill your much desired plants.