Vegetable garden pests and diseases need to be caught quickly, so that you can get the right control in place as soon as possible.
If you see any damage on leaves and buds, or you notice that the plant is unhealthy with discoloring and wilting, there may be some sort of pest or disease affecting the plant, particularly if this plant was previously a thriving and healthy specimen.
The following are a list of possible damage that you may discover, along with the most likely vegetable garden pests and diseases that is the cause of this damage, so as soon as you recognize that there is something wrong, you can start to solve the problem and save your veggies.
Wilting will tend to be through attacks on the root of the plant, and often when you notice plant is struggling, it is too late.
The likely culprits are the Vine Weevil larvae, Chafer Grub or Slugs.
To avoid the Vine Weevil larvae, look out for the irregular holes left on the leaves by the Vine Weevil, and if you find them destroy them or spray an insecticidal soap with chilli added to stop the adult from attacking the plants, and hopefully before they lay their eggs in the soil.
Regularly weed to stop the Chafer Grub from moving from its normal grass root diet to eating you vegetable plants. And hoe using a sharp Dutch hoe in and around plants to stop them from moving from one plant to another.
Dig up affected plants and search through their roots and through the soil to find the offenders and destroy them before they move to more plants.
The cabbage root fly grub is another pest that affects brassica roots and the first time you will be aware of the problem is when the plant is wilting and dying.
To protect your brassica from the cabbage root fly cut a 3 inch square sheet of cardboard or carpet underlay with an incision from the side to the middle. Place the square at the base of the plant slotting it through so that the stem fits in the middle of the square.
This will act as a barrier between the plant and the soil and stop the fly from laying eggs at the base of the plant.
Crop rotation is super important so you don't get issues with club root and other soil borne diseases. These can build up in the soil and affect subsequent crops.
Leaf eating pests tend to eat from the underside of leaves, so it is important to lift leaves when you are checking for pests. Slugs and snails are a big problem, and other than hunting at dawn and dusk there are a variety of ways of dealing with this type of pest.
Equal to the damage caused by slugs would be caterpillars, and it is worth being vigilant when checking the underside of leaves to see if there are any eggs, just a simple wipe will get rid of them. And if they do hatch, using gloves, collect and dispose of any you find. Also planting nasturtiums will help draw them away as part of a companion planting scheme.
If the problem is way out of hand you could resort to using a bacillus thuringiensis spray, this is a bacteria infection already present in butterflies, moths and their larvae, but upon contact with these larger quantities will kill their host.
The spray is short lived, so can only be used to cure the problem, and although it is slow acting, the infected caterpillars will eat very little.
Sprinkle the heads or growing shoots of brassicas with corn meal - the caterpillars eat that, instead of the plant, and swell up and die.
Other vegetable garden pests and diseases can be split into leaf eating pests such as leaf beetles, flea beetles, whiteflies, vine weevils and sawfly larvae, or diseases such as chocolate spot, blight, mosaic viruses and rust.
Most leaf eating insects can be controlled by collecting, companion planting, encouraging predators or the use of controls such as insecticidal sprays. Although there are some great tips for some individual pests.
For example, if you wave a piece of card with syrup on it above a plant infested with flea beetles, they will jump to get away from what they perceive as an attack, only to be caught by a sticky trap.
Similarly, if you spread syrup on a yellow card and hang it in the greenhouse you will take care of an attack of whitefly; this is because the whitefly is in some way are attracted to yellow, and will fly towards it, land on it, only to find itself trapped.
Vegetable garden pests and diseases that often manifest themselves on the leaves of plants, and can either look like leaf curl or colored growths on the leaf itself.
Blight is a common problem for potatoes causing a browning of the foliage which will, if left, cause the complete death of the plant. This disease is carried by the wind and is more common in damp weather, it tends to only affect the main crop potatoes, and is dealt with by removing the stems of a potato plant as soon as it is evident.
Don't compost this or any rotten potatoes - get rid of them in a bonfire or the trash.
Vegetable garden pests and diseases that affect broad beans tend to be Rust, Chocolate Spot and the Weevil.
Rust is a virus that affects the leaves and pods of the plant, to avoid it make sure there is plenty of space between your broad bean plants and remove and destroy any affected leaves. Chocolate Spot is another common fungal disease of broad beans and you should avoid collecting seeds from any plant that has been affected and burn the plants once harvested. The Weevil is not a big problem
Cucumber Mosaic Virus effects all squash plants and is carried by aphids moving from one plant to another. It is best avoided by guarding against aphids as the disease has no cure.
Vegetable garden pests and diseases that cause deformities and pale leaves tend to be sap sucking and would include aphids, whitefly, scale insects, thrips, leaf hoppers and woolly aphids.
Insecticidal sprays are very effective against these pest and with some chilli added it will put them off biting these plants, but even a blast of water could disperse them. Probably the most effective control would be vegetable pest predators and there are some great companion planting schemes that can help encourage these predatory insects.
Other vegetable garden pests and diseases could be parsnip canker, potato blackleg, swede soft rot, celery leaf spot, asparagus rust, onion neck rot or potato scab, but as you can see by the names of these diseases, they all tend to be specific to either a species or to the group of vegetable, and as such would be better approached as a vegetable specific disease. If you have a disease problem take a look at our A-Z how to grow section to find the vegetable plant that is affected.