| Symptoms and damage to the plant | Cause of appearance of these diseases or pests | Treatment |
| Diseases | | | |
| Botrytis (or gray mold) | Gray mold appears on the leaves, stem, flowers, and fruit. | This fungus grows in mild and humid environments, in poorly ventilated spaces. | To prevent this fungus from appearing during cultivation, make sure to properly space the plants when planting. Cut off the parts that have been infected, then spray Bordeaux mixture over all parts of the plant. |
| Circosporiosis | Gray spots appear on the leaves. | This fungus appears during cold weather in wet environments. | Treat diseased leaves with Bordeaux mixture or sulfur. To prevent the disease, make sure to properly space the plants when planting. |
| Fusariosis | The plant wilts.The root rots.The leaves turn yellow. | This fungus develops in heavy, wet, and poorly aerated soil. | Sprinkle the plant with an organic, sulfur- or copper-based fungicide. |
| Downy mildew | Brown spots appear on the leaves. The leaves then begin to fall to the ground. | This fungus develops in very hot weather and significant humidity. | When spots appear on the leaves, cut the infected leaves off so they do not contaminate other plants. Then spray Bordeaux mixture on the leaves. Apply nettle slurry to the leaves after watering. |
| Powdery mildew | A white layer appears on the leaves (a mold is forming). | This fungus develops in hot, very humid environments. | Properly space the plants at the time of planting. Cut off any infected leaves. Then spray the leaves with a mixture of milk and water (around 17 ounces of milk and one gallon of water) each week. |
| Phytophtora cinnamoni | The leaves and stem wilt, turn yellow, and dry out.The root rots. | This fungus develops in hot and wet environments. | Cut and burn infected leaves to avoid contamination of surrounding plants, then spray Bordeaux mixture on the leaves. |
| Ramularia | Light brown spots appear. Leaves then dry out. | The fungus appears in hot, very humid environments, in poorly aerated spaces. | To do as much as possible to prevent this disease from appearing, space plants well in rows at the time of planting. Cut off the leaves that have been infected, then spray Bordeaux mixture over the leaves. |
| Blight | Red spots form on the leaves, causing the leaves to fall. | This fungus develops when the weather is wet or when plants are too frequently watered. The fungus can appear starting in the beginning of spring through the end of summer. | When the first signs of the disease appear, cut and then burn infected leaves to avoid contaminating other plants. Then spray the leaves with a sulfur solution, horsetail slurry, or nettle slurry. |
| PESTS | | | |
| Flea beetles | Holes appear in the leaves (especially young leaves). | Flea beetles appear in hot and dry weather. | Spray nettle slurry on the leaves. Watering daily prevents this insect from appearing, as it does not like water. |
| Spider mites | They suck the sap from plants. The leaves turn yellow. Small, whitish webs appear on the leaves. The plant withers. | This pest thrives in hot and dry weather. | Spray water on the leaves, because spider mites do not like wet environments. |
| Caterpillars | Caterpillars chew on leaves. Holes appear in the leaves. | These pests start appearing in the spring, when butterflies begin to reproduce. | Spray the leaves with an organic anti-caterpillar product, such as pyrethrin, Bacillus thuringiensis, or Bordeaux mixture. |
| Snails | A path of slime left behind by snails will appear on the leaves. Snails come to eat young leaves. | They appear in wet environments or just after a period of rain. | To prevent snails from appearing, place wood shavings, ash, or hay around the plant so the snails are unable to climb onto the plants. You can also place a bowl of beer near the plant, a favorite with snails. |
| Slugs | A path of slime left behind by slugs will appear on the leaves. Slugs come to eat young leaves. | They appear in wet environments or just after a period of rain. | To prevent slugs from appearing, place wood shavings, ash, or hay around the plant so the slugs are unable to climb onto the plants. You can also place a bowl of beer near the plant, a favorite with slugs. |
| Aphids | Aphids attack leaves and suck the liquid from them, causing plant growth to slow. Leaves dry out, turn yellow, and fall. The leaves and flowers are deformed. | Aphids can appear starting in spring through the end of fall. Starting in spring, aphids multiply rapidly with the hatching of their eggs. | They are many techniques to prevent these pests from appearing. Spray nettle, fern, or rhubarb slurry on the leaves. Spray soapy water (made with black soap) onto the leaves. Ladybugs will eat aphid larvae. |