Taking good care of tomatoes
At planting time, sturdy young tomato plants show no sign of trouble ahead but wise gardeners are on watch.
Tomatoes are tigers for punishment, attracting more than their fair share of summer pests and diseases. Especially where the terrible Tomato and Potato Pysllid has made its presence felt, it can be tempting to throw one’s hands up in defeat.
But the fact remains, there is no denying the superior taste of a home grown tomato. Bugs can be beaten. The trick as always is to know your enemies intimately and then take the common sense approach known as ‘Integrated Pest Management’.
START WITH HEALTHY PLANTS
Some tomato varieties are more disease resistant than others. Depending on where you live and which pests or diseases are more problematic, there will be varieties that fare better in your garden than others. Working out which are best for you is largely a matter
of trial and error plus sharing success stories among friends and neighbours. Ideally, select a diverse selection of varieties known for their disease resistance. Grafted tomato plants offer disease resistant roots and extra vigour. Early ripening varieties can provide a crop before the worst pests and diseases take hold.
SUPPORT VIGOROUS GROWTH
Regardless of variety, a healthy, well fed and well watered plant has a better chance of fighting off attacks from pests and pathogens than a sickly malnourished one. Healthy plants need healthy soil. Deep, dark and spongy soil, rich in organic matter ensures water and nutrients are easily accessible to plants and, whatever your preferred way of feeding them, tomatoes need a continuous supply of nutrients to support their rapid growth.
Infrequent soaking encourages young roots to grow deeply into the soil where there is a good supply of moisture and nutrients. Frequent shallow watering encourages shallow root growth more likely to suffer in a dry spell. Apply water directly to the soil. Sprinklers are best avoided as wet leaf surfaces invite disease. Mulching with a layer of straw or fine bark will help keep the moisture in the soil where it is needed.
Tomato bugs thrive and multiply in humid conditions. Keeping the above ground parts of the plant dry and well aerated is key. Keep your tomato plants weed-free with plenty of space for air. Too much air movement, however, isn’t helpful as wind damage is a potential entry point for disease.
Avoid planting tomatoes or their relatives (potatoes, capsicum, chillies, eggplants) in the same place year after year. The longer a garden bed has a rest from any one plant family, the better. If it’s too hard to change the planting place, consider changing the soil or planting tomatoes in containers.
Be aware that disease spores can be transferred from one plant to another via tools or fingers. Also, avoid pruning tomatoes on a wet or humid day as moisture assists disease entry. Seed saved from an infected crop may carry over disease to the next crop. Be sure of your source or obtain fresh seed or seedlings from a reputable supplier.
When lower leaves show signs of disease remove them, ideally with clean sharp tools. Sometimes it may be necessary to remove an entire plant. Refrain from adding infected material to your home compost heap, which is unlikely to get hot enough to kill all the disease spores and insect eggs.
TAKE GOOD CARE OF NATURE
Every pest has its natural predators. Think carefully before spraying pesticides and try planting a variety of herbs and flowers to attract a range of predatory insects. Read more on page 31.
KNOW YOUR ENEMY
Whatever your crop, awareness and early intervention are an essential first line of defence in the battle of the bugs. Observation can be a lethal weapon so keep a close look out for the first signs of a problem especially as the weather warms up in summer. It’s easier to come up with creative solutions when you know how your pest’s favourite environmental conditions and how it lives and breeds.
Spraying with protective fungicides such as copper provides effective control against fungus diseases when applied early in the season before the disease cycle takes hold and when wet weather or high humidity makes infection likely. Copper is an accepted organic spray option, but its overuse is a concern for soil health.
When all else fails, spraying with the right product at the right time can be the most cost effective option to save a crop under threat. Garden centres are a good place to go for help in choosing the right product. Today’s registered home garden pesticides are at the very low end of toxicity and pose no risk to humans when used as directed. Several are also safe to bees once they have dried on the plant. Neem tree oil is a natural product that controls a wide range of insects. It can be applied as a spray or as granules in the soil. All pesticides, including natural sprays have the potential to harm beneficial insects and soil microorganisms.
Mesh crop cover fabric is now available in garden centres and is an effective way to prevent insect pests including psyllids from laying their eggs on crops.