Every gardener runs into a few difficulties at some stage. It could be the weather playing havoc with your crops, or a pest or disease that’s out of control. Other times your plants just sit there showing a complete lack of vigour. It’s not just novices – even the most experience gardeners face these challenges, and when you learn how to solve the problems you naturally become a better gardener. Prevention is always better than cure, so here are a few of the diagnostic tricks that green thumbs use to stay one step ahead of typical garden problems.
Phil Dudman

6 Jul 2012 - 12:30 PM  UPDATED 5 Jul 2017 - 4:23 PM


Regular diagnosis

Good troubleshooting starts with regular diagnosis. Make it your business to go out and have a good look at your plants as often as you can, every day if possible. Have a really close look to see if anything has changed. If your plants look unhappy, ask yourself why. Start with the basics. Are they getting enough sunlight? Is there enough moisture in the soil? Perhaps it is too wet? What about feeding? Are your plants getting enough? Often when a plant doesn’t look as good as it should, it comes down to one or two basic needs that are not being met. When your plants are getting everything they need, they naturally look healthy and robust and are generally more resistant to other potential problems such as pest and disease attack. When you check your plants regularly, you can monitor any change in your plants appearance and respond to their needs quickly, keeping them happy and healthy.


Pest and disease

Most crops are susceptible to some form of attack from pests and diseases. The trick to managing potential problems is to control small outbreaks, before they become big ones. If you notice an unwanted insect or a blemished leaf, pick it off before it spreads and creates more damage. You don’t need a lot of gardening experience or knowledge to start doing that, but it does pay to identify and understand any particular pest and disease problems in more depth so that you can be ready to manage them in the future. We take a closer look at how to deal with common pest and diseases below. If you’re not sure about a particular problem in your patch, you can post pictures and ask questions on our Facebook page.



It’s important to keep on top of weeds in the garden, especially the vegie patch. Weeds compete with plants for water, nutrients and light, and when they are properly managed, your plants will grow better. There’s an old saying, 'one year’s seeding make’s seven years weeding’. Most weeds grow quickly and set lots of seed, making more weeds – that’s why they are such successful plants. Check your garden regularly for weed outbreaks and take action to control them before they get out of hand. Whenever you are watering, fertilising, harvesting or just pottering about, pull a few weeds, chip them with a hoe, scuff them up with a trowel, or cover them with mulch to deny them of light – whatever method suits you.


Weather challenges

Any farmer will tell you that no matter how good a grower you are, one bad weather event can destroy a beautiful crop in moments. It’s difficult to control the weather on a large scale, but it is possible on a small scale. That’s the beauty of backyard growing. With a few simple safeguards in place, you can control heat, cold, excessive rain and hail. The basis of your defense is a frame on which you can drape over some sort of cover to protect your plants from the elements. A length of shadecloth will reduce the suns intensity on hot days as well as protect crops from damaging hail. A sheet of clear nursery grade plastic will shed excessive rainfall and also trap heat protective heat when frost is about. The frame needn’t be elaborative – you can make a simple frame using bamboo stakes and irrigation polypipe to form a dome. If you are in a hurry, just drive a tomato stake in the ground at each end of your vegie patch and connect them with a long the length of bamboo before throwing over your cover to form a kind of tent.


Pest disease and control

At some point in your growing journey, you are bound to discover a few unknown pests or diseases competing with you for the rights to your crop. It can cause you a lot of grief when you’re starting out, but don’t give in, because as you gain experience, you’ll be better equipped for managing these problems. To save you some heartache along the way, here are some guidelines to help you take on pests and diseases before they take over.


Plant health

Think of plant health in the same way as human health. The times that we are most susceptible to illness and infection are when we are run down, and it’s the same for plants. Poor plant health is like a giant billboard inviting pests and diseases to step in and take charge. Good defense starts with good health. When you create good growing conditions for your plants – healthy soil, lots of sunshine, regular soil moisture and a balanced diet of the nutrients they need – your plants will be stronger, more resistant and less attractive to invading pests and disease organisms.


Garden layout

If one plant is attractive to a few pests, then a big group of them is irresistible and soon becomes a feast where all their friends and family are invited. Try to avoid monoculture in your garden i.e. large areas of a single plant species. Monocultures provide the perfect environment for pests to thrive. Once pests get word of their favourite meal, they move in and multiply, spreading quickly through the whole crop. Mix up your planting to include a variety of different plant types. This reduces the possibility of complete crop loss. A variety of plants can also attract a variety of insects, some of them predators that feed on pests and help to keep numbers manageable.

When you grow a particular crop in the same spot time and time again, you can get a build-up of pest and disease populations in the soil to the point where they become more difficult to control. Ideally, specific vegetable crops (and their relatives) should not be grown in the same soil more than once every 3-4 seasons. Once you harvest a crop in a particular bed, sow something of a different plant group. This is commonly referred to as crop rotation.


Get to know your friends and foe

Be prepared. The best way to protect your crops from harm is to get to know the different pests and diseases that could potentially affect your crops. Armed with this knowledge, you will be in a much better position to respond to early invasion. Some insects are harmless, so be familiar with the good guys too. Similarly, some blemishes found on leaves or fruit may be harmless and require no action.