Gardening and growing great plants.

Scale insects on lemon tree.

A customer bought in a lemon the other day and it was amazing how many scales were on just this one lemon, let alone what must have been on the branches.

These scales eat the goodnes out of the plant cells. They can literally bite into the skin of the plant.

Heavy infestations like this one will weigh heavily ony the plant. Often a weaker plant will then be left vunerable to a getting a secondary problem. One such secondary problem is sooty mould which will grow on the sugary waste from the scales called honeydew. Ants may also may inhabit the plant in greater numbers and even assist scales by carrying around young insects and clearing away all the honeydew that might otherwise choke a scale colony.

The plant branches and leaves may then have poor distorted growth and eventually branches could even die. Fruit like this can be contaminated or discoloured, although this particular fruit still appeared to be ok inside.

Scales are weird because they don't really look like insects at all. For most of their lifecycle they are hiding under protective shells. They overwinter as mature females, and lose the use of their legs.

In spring, the females produce 'crawlers' which are very young insects which move out from under the shells and move to new feeding sites. They then form the shell like scale and can no longer move. Many generations can be produced over one summer. They infect fruit like this late in the season. Only the small males fly, but 'crawlers' can be blown in the wind.

Control: This plant should have been sprayed with white oil (also sold as Pest oil) in the warmer months, being careful not to burn the plant. Do it on a cloudy day, and maybe even with a test spray. It could still be white oiled in winter, but the insects are much more protected by then and it will be less effective. You could also prune the tree now and dispose of the branches in the bin. An insecticide like Carbaryl could also be used, but stay on top of this problem with white oil, and instead wait for the ladybirds to help you in summer.

The May nursery report.

Last month the garden show in Melbourne had over 110,000 visitors. Two weeks later here at the nursery we were inundated with hundreds of people wanting to save water and swap their old twist nozzle hose for a free trigger one. We ran out on day 2. On top of this nurseries all over Melbourne recorded excellent Easter sales and the state government announced a relaxing of water restrictions. All in all it has made me realise that the joys of gardening are being appreciated by more and more people every day. It makes me so pleased for the wholesale growers, because like many agricultural pursuits, in some years it can be a heartbreaking occupation. 

The reason it can so quickly go from joyful to heartbreaking, is of course because of mother nature. Take the roses this year. With cooler weather and more rain and dampness around, black spot has proliferated.  High humidity in March only added to the problem. So you need to work out a strategy. Remove all fallen leaves as they will house the fungus. Never water the leaves on the plant, and prune back affected branches to healthy wood. Spray with lime sulphur in winter and keep roses well fed throughout other times of the year. Wow this sounds like a lot of effort yet we will sell over 3000 roses this winter. Why? Well yes, there could be some pain along the way - but when those first buds break into bloom, you know it has all been worth it. 

Those cymbidium orchids you had hiding in the shade over summer can be brought out to a sunnier position now to promote spring flowering. Check for snails under the rim of the pot as they love hanging around for new flower buds. Raising the pots on couple of bricks will also make a big difference with the increased airflow. Water plants regularly during periods of dry weather.