chard disease

Asked June 6, 2019, 7:54 PM EDT

Hello, I have a problem with the chard growing in my garden plots. I have planted chard in two different plots on different sides of the house and both areas have the same problem. The chard is basically drying up, or shriveling. Either something is eating it, or it's a disease, or a soil issue. But like I said it is doing the same shriveling and drying in different areas. On our main plot, next to the chard I also have planted lettuce, kale, tomatoes and chili peppers. None of these other plants are exhibiting any signs of problems. JUST the chard. What is going on? I would be very thankful if you gave me any suggestions, as I am going to be losing two dozen chard plants pretty soon due to this issue!!! thank you! Gosia

Multnomah County Oregon insect issues swiss chard

2 Responses

Hello Goisia,

Chard sometimes takes time to get established, unlike lettuces which grow rather profusely. Once established, however, they continue to produce delicious green for a long time.

Chard is a close relative of the beet. It grows in cool weather, but also tolerates heat more than lettuce. I think your plants may be suffering from the temperature swings we've experienced this spring.

Chard are grown for the leaves. The water on the leaves may be causing a problem. Try turning over your hose so the holes faces the soil rather than acting as a long sprinkler. That kind of soaker hose works in both ways. Give the plants a light dose of organic fertilizer to jump-start leaf production, keep them dry and mulch to minimize soil evaporation and keep down weeds. Keep well-watered during the summer. This article has additional information on growing chard, Swiss Chard

Hello Gosia,

On further reflection the problem with your chard plants is more probably blotch leaf miners.

Blotch leaf or spinach leaf miners (Pegomya betae) cause real problems with green, leafy vegetables. Adult leaf miners are very small gray to brown flies, 1/4-1/3 inch long. The flies emerge from pupae in the soil where they've overwintered in late April, May and June. They then lay white eggs in groups of 4-8 on the underside of the leaves of chard, beets and spinach and other vegetables. The eggs hatch and white cone-shaped larvae tunnel into and within the leaf tissue, creating areas of dead tissue in the leaves which turn opaque and then brown. The larvae are protected within the leaves, making control difficult. Larvae are active for 2-3 weeks then they drop to the soil and pupate to start the whole cycle over again. The entire life cycle is 30-40 days. There are 3-4 generations per season. Look at the underside of the leaves for eggs and for larvae.

To control leaf miners remove infested leaves and destroy them - do not compost them. Squish any larvae you find in the leaves. Populations will build up in numbers over the generations. Insecticides can prevent adult flies from laying eggs, but won't kill larvae within the leaves. Spinosad is a good control with minor impact on other beneficial insects, but must be applied multiple times.

Because the insect pupates are in the soil, avoid planting spinach, chard and other vulnerable vegetables in the growing area. To avoid the pupae of these leaf miners plant the vegetables in a different area of your garden, as far away as possible. Use row cover to prevent flies from other areas of the garden from flying over and laying eggs on your new vegetable area. If you use row cover in areas with pupae already in the soil it will just keep the insects protected. This article has additional information as well as pictures of adult flies and typical damage, Leaf Miners