Tomato Success Series – The top 3 pests to protect your tomatoes from

Thanks so much for all your positive feedback and support with this Tomato Success Series – I’m delighted you’ve found it so useful and look forward to seeing juicy pics of your tomato harvests this season!

As we all know, tomatoes and tomato plants can be prone to a lot of pest and disease. This week, the Success Series will focus on the pests that can attack tomatoes.

Remember that pests and disease only affect your tomatoes if the soil is not at optimum health or your plant becomes stressed over summer. The first thing to do is to be observant of your plants and identify the disease.

Pests – the top three enemies to watch out for!

Tomato Enemy #1: Whitefly

Whiteflies are tiny flying insects that feed on plant juices and leave a sticky residue behind, which can become a host for sooty mould.

These insects live on the underside of the leaves, as most insects do.

The best way to find out if you have these is to give the plants a tap and they will fly up into the air.

The best way to treat whitefly is by spraying regularly with a good oil or to hang sticky yellow traps up. You can buy these from any good garden centre, or even make them yourself at home with some yellow card, smothered in Vaseline and then hang near the plants.

Whiteflies can be very damaging if you are growing in a green house. Spray the underside of the leaves in the morning with the oil and repeat every two weeks.

Another way to prevent an infestation of whitefly is to plant beneficial flowers that will attract natural predators such as lacewings and ladybugs. These plants will bring the predators into your garden and they will consume up to 1,000 whitefly a day. To learn more about whitefly and companion planting to prevent them, check out one of my earlier blogs here.

I strongly encourage you to check your tomato plants regularly, as these diligent little insects can create a big infestation over a short period of time.

Tomato Enemy #2: Cutworms

Cutworms are the caterpillars of moths that lay their eggs in the soil.

When the caterpillars emerge, they chew on the young, juicy new plants and cut them off at ground level, either eating part of the stem or all of it. You can wake up one day to find your plant suddenly cut off at its base overnight, lying on the ground without a bug or insect in sight!!

The caterpillars can grow up to 4cm long and vary in colour from light grey, brownish to almost black. When they are disturbed they curl up like the picture above.

They only eat at night and hide in the soil during the day, becoming most active after periods of rain.

If you have these in your soil the only way to protect your plant is by putting a barrier around your young plant and sinking it into your soil. When digging or transplanting, please be observant of what appears out of your soil – if you see these, it is a good idea to remove them!

Tomato Enemy #3: Psyllid

Over the past few years, this insect has become more and more rampant in tomatoes, capsicum, chilli and potatoes.

The psyllid first became a real pest in 2006 and originates from central and north America. It is very tiny secretes a toxic saliva that severely damages the plant. This is a pest that commonly arrives with your new plants bought from garden centres.

The symptoms of psyllid being present is a slight discoloration of the top leaves along the rib and the edges. Then the whole plant can turn to a yellowish green.


These pests are tiny and very hard to see. Yet again, I can’t stress the importance of looking under the leaves of your plants. Most eggs and pests are under the leaves doing the damage before you even know it. They love to feed off your plant by sucking away at its goodness, and this can cause uneven growth of your plants, misshapen fruit and even for the flowers to fall off.

Psyllid breed all your round – just a bit slower in the winter – a female can lay up to 500 eggs over a 3 week period! In Auckland, there can be as many as 8-10 generations a year!

Again, this is an important reminder to have bio diversity in your garden by planting beneficial insect flowers to attract the right predators.

Lacewings will eat nymphs which can help with your infestations. I also recommend that you plant yarrow, dill, phacelia, cosmos, feverfew and sunflower to name a few.

I tend to put a micronet over my young seedlings which stops the eggs being laid, but you need to be sure if you are buying plants that they have no eggs on them otherwise covering them won’t help at all. If I do buy plants from a nursery I always spray them with a good oil when I get them home, and again on a regular basis.

Remember as the weather heats up to be observant at all times!

Good luck with these tomato enemies!

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