Things that Bite
In Australia we have a lot of pests that love to take a bite out of your roses. These range from the small pests like catapillars and beetles to the larger two and four footed pests. Some we own and some that come into our garden. Anything from thrip to possums, Parrots to Wallabies, goats, deer and horses.
The first thing to do when you notice parts of your rose bush missing is to identify the culprit. The size of the bite will help here.
Most large animals will take the top of a stem or a whole leaf leaving an often shattered stem or will cleanly take a whole leaf. This covers all from Possums upward.
Parrots will take the new growth from a plant either the whole top or leaving the new growth hanging by a thread. There will be a recognizable bite mark and often bits of the new growth littering the ground.
Catapillars will chew holes in your leaves or leave just the skeleton of the leaf.
Thrip, aphids and spider mites will leave the plant material but take the sap leaving brown edges to the petals or leaves that look like they have been through a dust storm.
Most if left unchecked will ultimately distroy your plant.
Once identified then you have to decide how to get rid of them.
1. Physically remove the pest from the plant - this works from catapillars being picked off the rose bush to an electric fence keeping away the larger animals. Bird scare tape is very affective against parrots.
Possums are difficult and an effective treatment is still being sorted out by many gardeners. Either use the companion planting or garlic spray to educate them not to eat the roses, alternatively a big dog or electric fence can deter them. There are many different ideas on the internet from spikes on the fence to buying a repeller or paying someone to move them. Good Luck on this one.
2. Chemical sprays for the insects - This is NOT recommended unless as a last resort. Insecticides can kill the natural predators as well as the target pest. In most gardens a balance is acheived amongst the insects and disturbing this can cause trouble. If you must spray try the Pyrethrum based insecticides, Eco-oil or a Neem based spray.
3. Hoseing the insect off with water - This is great for small infestations of Thrip, Scale, Spider Mite or Aphids. All of these come into your garden during the hot weather and do not like water. They will soon move on if you remember to spray under the leaves as well as on top. They may lay eggs during the first visit to your plant so keep an eye out for the second coming in a couple of weeks and repeat the hose solution.
4. Companion planting - This is a great long term solution to most insect problems. Lavender, chives, marigolds, mint, garlic and many more. These plants can add to the health of your plant and also slightly change the taste of the rose bush so the nibbling animal or insect dislikes the taste. It will take a few weeks for the taste to be changed on your rose after planting beside the rose bush so be patient.
5. Garlic or Chilli spray - This is like the companion planting but is instant. Although it will have to be repeated each week for a couple of weeks or after it has rained. It will not last so it is a good idea to companion plant as well. Take two teaspoons of crushed garlic or chilli and put into 500mls of water. Let this sit for a couple of days so the water is very potent. Strain and spray onto the plants.
6. Predatory insects - These are for sale on the internet and can be shipped to you. They are very often affective but remember once they have rid your garden of the target pest they will go wandering off to other gardens to find more food.