Parsley is a strong plant that does not often suffer from insect infestations. Prevention is often more effective than resorting to chemical controls. The following will provide some tips to help you prevent pests from attacking your parsley.
Parsley is a very strong growing plant and as long as it is healthy, it will resist most insect attacks. Keeping parsley healthy is all about keeping the soil in the best condition. Don’t use chemical fertilizers on your soil. These can add salt and drive away earthworms. Earthworms are vital to soil health because they help ventilate the soil by digging tunnels and the castings they leave behind are probably the most nutritious organic fertilizer available. Water your plants in the morning to reduce evaporation and to give the leaves time to dry to prevent molds growing. Healthy plants in healthy soil suffer less damage from insect attacks.
The rust fly larvae attack the small, fibrous roots of plants and even tunnel into the larger roots. There is often little outward sign of an infestation until the plants start to die. Once the rust fly has become established, there is little chance of getting rid of it. Some damage can be avoided by planting late in the season, mid to late June, missing the first hatching of the adults.
Infected plants should be destroyed immediately. You can cover your plants to prevent flies from laying their eggs on them.
Parsley worms are the caterpillars of the black swallowtail butterfly. Although the parsley worms can do enormous damage to plants, the butterflies are beautiful creatures. The caterpillars are large enough to be removed from the plants by hand so you can transfer them to plants that are not so valuable. If you keep a small patch of weeds in your garden, that would be an ideal location for them. If you want to keep some of the caterpillars, you can also sacrifice a few parsley plants.
Spider mites are tiny spider-like creatures that feed on the soft skin of the plant leaves. Spider mites reproduce rapidly and in a rich food area, will soon become a major pest. Being so tiny, the damage of one spider mite is negligible, showing up as a small yellow spot. An attack by great numbers will leave the plants looking decidedly spotty. The only real protection against spider mites are spider mite predator bugs, which you can purchase. They work well on indoor infestations, but not so well on outdoor infestations.
Parasitic wasps feed upon all sorts of caterpillars. They are very tiny and kill off caterpillars by laying their eggs inside the body cavity. The larvae that hatch devour the caterpillar before it can pupate into a moth or butterfly to start the whole process over again. Dill attracts the parasitic wasp because the aroma it gives off will attract butterflies and caterpillars.
Maintaining healthy plants in healthy soil is your first line of defense. Combined with predator bugs, this should be enough to keep your parsley safe and sound.