Top 5 summer tomato problems

<p><em>From GARDENA and YATES Brand Ambassador Sarah the Gardener</em></p><p>The star of the summer garden has to be the tomato. There is nothing like eating a sun warmed tomato plucked straight from the plant.</p>

Although as wonderful as it is to have tomatoes in the garden, they can run into a few problems. Getting them off to a good start in the right conditions is key to healthy, robust plants.

Tomatoes need:

  • A full sun position with at least 6 hours of sunshine.
  • Rich free draining soil with plenty of organic material worked into it.
  • A sheltered and supported from the wind. Tomatoes can get up to 2m!
  • Wait until all risk of frost has passed and the soil is warm enough before planting.
  • Avoid overcrowding. Give plants plenty of space for good airflow.
  • A regular liquid feed suited to tomatoes supports healthy growth
  • Water consistently, watering at the soil. Avoid splashing water onto the leaves. A good thick layer of mulch helps retain soil moisture.
  • Practice good hygiene between plants. Hand sanitiser is great to clean tools.
  • Plant in a different spot each year.

Plants with good overall health are less vulnerable to many problems. Although problems can still occur, and the best preventative action is the gardener’s shadow. Check your plants as often as you can. As soon as a problem presents itself take immediate action.



Tomato Blight

Blight can be devasting as the best advice is remove affected plants. It shows up in warm humid conditions and stressed plants are at greater risk. In high risk conditions preventively spray with Yates Liquid Copper Fungicide every 7 -10 days on upper and lower leaf surfaces. It can also appear in potatoes, capsicum and eggplants.

It is a fungal disease that comes in two types:

EARLY BLIGHT – caused by Alternaria solani. Has spots on leaves that look like a bullseye, brown lesions on the stems and fruit rot. It often shows up on the older leaves first.

Prune older leaves to reduce the risk and improve airflow. Use clean and dry tools between plants.

In the very early stages, try saving the plant by removing just the affected parts and spray with copper.

The best advice is to remove affected plants and bin or burn. Don’t compost. Wash all tools and gloves etc that come in contact with affected plants.

LATE BLIGHT – caused by Phytophthora infestans. Has irregular brown / black patches on leaves and stems and brown wrinkled patches on the tomato. If you find this act immediately. It is highly contagious and causes plants to die quickly.

Remove affected plants and all plant debris on the soil surface and bin or burn. Don’t compost. Wash all tools and gloves etc that come in contact with diseased material.

Tomato Potato Psyllid (TPP)

A relatively new pest that can be devasting. A sap sucking insect that looks like a small cicada, the size of an aphid. The eggs look like tiny pins on the edge of the leaves and the juveniles look like small green scale on the underside of leaves. The tell-tale sign is the droppings look like sugar sprinkled on the leaves.

Aside from the harm caused by sap sucking, the TTP spreads the bacterial pathogen Liberibacter, which causes yellowing leaves, curling leaves, stunted growing tips and small misshapen fruit. Affected plants need to be removed, binned or burnt to avoid the spread.

Check plants often for signs of infestation and remove infested leaves. Spray with Yates Success Ultra Insect Control every 7- 14 day, particularly under the leaves.

Use of an insect mesh from early spring can provide a barrier, but continue to check plants often.

Blossom End Rot

A rotten, sunken looking back end on tomatoes isn’t a disease but is a nutrient deficiency caused by environmental conditions that prevent calcium being taken into the plant from the soil. Most commonly it can be caused by overwatering or low temperatures which is why it is more common early in the season. However, being too dry, too acidic or a soil too nutrient rich can also cause problems.

Avoid moisture stress with regular watering and a good thick mulch. Adding Yates Thrive Natural Garden Lime when preparing the soil increases the pH and improves nutrient availability.

Splitting And Cracking

Cracks in your tomatoes can be disappointing and is caused by a sudden increase in water. For robust tomato skins ensure watering is consistent and mulch to help retain an even soil moisture. Tomatoes can ripen off the plant so if heavy rain is expected, pick all fruit showing signs of ripening to avoid splitting.

Green Vegetable Bug

This insect pest- Nezara viridula becomes more prolific from midsummer onwards. This sap sucking shield bug is bright green and 1.5cm long with juveniles that are more rounded and black, white and red. Where they pierce the tomato to suck the goodness they leave behind a hard, white corky growth in the tomato flesh. Catching and squishing is an effective control when numbers are low. They do release an unpleasant smell. In heavier infestations an insecticidal spray may be necessary.

There are other things that can go wrong with tomatoes during the growing season that can be caused by weather or environmental conditions and pest and disease population explosions. If you notice anything not right with your plants – spots, wilts, discolouration or infestation, take a photo down to the experts at your local Mitre 10 garden centre to help you find the best treatments and course of action.

Homegrown tomatoes have such a depth of flavour that can’t be found anywhere else, not to mention the vast array of tomato varieties available to the home gardener when grown from seed or seedling. So in spite of the possible problems it is always well worth the effort.