We all put in a lot of hard work when we plant our tomatoes but now is not the time to become complacent!!! The key to successful tomatoes (or any edible crop for that matter) is protection and prevention against disease and insects. I grow buckets of tomatoes every year and I swear by Wally’s Secret Tomato Food with Neem; used at 4-6 weekly intervals it keeps my tomatoes pest free (which is what the neem is for) and also keeps the plants healthy. The other product that is essential is a spray called Copper (which is a natural fungicide) and you should use this every 3-4 weeks. There are plenty of other products that you can use as well but with any edible crop in my opinion Neem granules are a must have to keep your plants pest free. Problems that occur with tomatoes are normally from an insect, a fungus, from fluctuating temperatures or watering. If you can’t match up what’s wrong with your fruit to the tomato doctor or if you are still unsure bring in some of your problem fruit/ leaves and we will be sure to help you.
Weather or fertiliser related
Rolling of older leaves
Caused from fluctuating temperatures. Mulching it helps control the soil temperature.
Causes paper-brown patches on the fruit. This is caused by exposure to bright sunlight. This can be easily prevented by leaving the older leaves on so that it provides natural shade for your plants (so don’t be tempted to take off the older leaves to help ripen your fruit more quickly).
Tomato Fruit Splitting
Usually caused by changes in watering practices. Tomatoes become accustomed to the amount of water they receive; when watering is increased over a short time span it causes a growth spurt. The fleshy tissue of the fruit will grow much more rapidly than the skin, causing the skin to split. The fruit is still able to be eaten but the splits will however make the plants more susceptible to viral infections. When growing tomatoes regularly water. If this is an ongoing problem you might want to purchase varieties that are resistant to cracking such as Big Beef.
If your fruit doesn’t ripen and has a blotchy appearance it is from too much heat, too little potash and excess watering. Feed plants with Tui Tomato Fertiliser or Wally’s Secret Tomato Food. If it still continues you may need to supplement feed with Sulphate of Potash.
Tops of Tomatoes are green
Is caused from excess sunlight, being too dry and too much potash. Apply Sulphate of Ammonia and water regularly.
Blossom End Rot
Is from a calcium deficiency and also happens when tomatoes are ripening rapidly from irregular watering. Water plants regularly while growing. Add gypsum prior to planting to boost calcium and apply mulch around plants to help with water retention. You can also add OCP Liquid gypsum.
Leaves are yellow between the veins. Feed plants with Tui Tomato Fertiliser or Wally’s Secret Tomato Food. If it still continues you may need to supplement feed with Epsom Salts or Sequestron.
Plants wilt and often the leaves pucker and are distorted because the aphids suck the sap from the new growth before it opens. The insects live on the underside of the leaves.
Leaves are mottled and look yellowish and dehydrated. These minute insects live on the undersides of the leaves.
Tomato Fruit Worm
Small caterpillars tunnel holes into the fruit.
Unfortunately once you have it you may as well destroy the plants. Personally I would use Yates Success Ultra or Mavrik but testing so far shows that nothing seems to kill these insects once you have got them. One of our Veggie Gurus at Oderings believes adding Neem granules regularly during the growing season is worth a shot. Dispose and destroy effected plants.
Tiny white insects on the undersides of the leaves that when disturbed will fly around.
Small spots appear on older leaves and there is dark mould present. This is more common in warm weather. Prevent by spraying regularly with Copper. Dispose of affected plants.
Irregular brown patches on leaves. This is more serious in wet, humid climates. Prevent by spraying regularly with Copper. Dispose of affected plants.
Leaves, stems and fruit develop a grey brown rot or mould.
Older leaves show yellowing blotches with grey mould under the leaves. Younger leaves show pale circular spots.
Verticillium Wilt/ Bacterial Wilt
Drying and withering leaves. Do not grow in the same area for more than one year in three. Plant Verticillium resistant varieties such as Big Beef, Grosse Lisse or Roma.
Leaves, stems and fruit develop grey powder on the leaves. Use Fungus Fighter.
Rolling of older leaves
Blossom end rot
Verticillium wilt /bacterial wilt