Yellow Leaves on My Growing Tomatillos

Yellow Leaves

• Nitrogen deficiency causes tomatillo leaves to yellow. Nitrogen is mobile within the plant, going to new growth first. Older leaves turning yellow may indicate a nitrogen deficiency in the soil. Nitrogen is the most used of the 13 nutrients plants need to grow and thrive. Nitrogen is obtained through adequate organic matter in the soil. Composted soil contains the full spectrum of nutrients needed, including nitrogen. Add a shovelful of mature compost to each tomatillo at planting time.

Possible Causes

• Overwatering a tomatillo plant may cause nitrogen deficiency and yellowing of the leaves. Irrigate tomatillos when the ground is dry to the touch. Water deeply and do not allow water to stand around the plant base. Soil should be friable and drain easily. Cover soil around the plant with a 2- to 4-inch layer of mulch material such as straw, dried leaves or mature compost. Mulch keeps the soil temperature even and prevents weed growth.

Aphids

• Yellow, distorted or curled tomatillo leaves are caused by aphid infestation. Aphids are tiny, soft bodied, pale green insects that gather in colonies on the underside of leaves and on stems. They are prevalent in spring when new growth begins. Aphids are controlled by spraying them off with a strong stream of water. Companion plants that strengthen tomatillo resistance to disease and harmful insects include beans, basil, chives, garlic and marigolds. Ladybugs, hover flies and lacewings feed on aphids.

Wilt and Virus

• The curly top virus causes tomato and tomatillo plants to turn yellow and stop growing. Fusarium wilt and mosaic virus distort and discolor leaf tissue. Wilt and virus problems spread easily and spores may overwinter in the soil. Remove affected leaves as soon as they are noticed. Do not place diseased leaves in the compost pile; it is more effective to burn them. Yellowing usually begins at the bottom of the plant and moves upward. Remove the entire plant if the yellowing continues.