1. Seeds fail to germinate
A. Poor Quality Seeds – If you purchased your seeds locally , always check the date on the packet that lets you know when the seeds were packaged. The older the seeds, the lower the success rate. If you have older seeds you still want use plant more than will need to ensure a reasonable amount of successfully germinated plants.
B. High Temperatures when beets were planted will cause them to not emerge . Mulching bed with aged compost will help, also be sure to Keep the soil evenly moist until seedlings break the soil surface.
2. Seedlings cut off near soil level
Cutworms are a common pest of Beets , they are soil grubs which are 1/2- to 3/4-inch long that are found under the soil. They chew roots, stems, and leaves. See Cutworms for more information.
3. Seeds and seedlings rot
Seedlings sometimes droop and collapse shortly after they appear. This is commonly due to “damping off” caused by a soil – borne fungus. It is more common in areas of high humidity.
Don’t plant in cold, moist soil. Be sure the soil is well drained. Do not over water. Dispose of any damaged seedlings – not in the compost either – bag them or burn them.
4. Holes in leaves of seedlings
Holes in any foliage is a sign of an insect problem cabbage looper and flea beetles are the most likely culprits in beets at this stage.
A. Flea beetles will chew small holes in seedlings. The larvae will feed on the roots . See Flea Beetles for more information.
B. The cabbage looper is a green caterpillar with thin yellow stripes running down its back. Practice Proper Garden Sanitation, Keep garden clean of plant debris where the adult moth can lay its eggs. See Cabbage Looper for more information.
Other less common culprits are blister beetles, which will attack more mature plants.
5. Leaves partially eaten and webbed together
Beet army worms webworms or several similar varieties of garden worms are the culprits. The webworm attacks beets, it is the larvae of a tan yellow moth with gray markings. The worms / larvae will spin a light web around the plants.
Clip off and destroy any leaves that are webbed. In light infestations hand picking is feasible, destroy the caterpillars. Keep the garden weed free and practice good garden sanitation. See Worms for more information.
6. Leaves yellow, curl under, or deformed
Frequently caused by sap sucking insects such as aphids. They are minute, pear-shaped insects that infest on the undersides of leaves.
They drop their excrement “honeydew” which leads to other disease problems – black sooty mold. Insecticidal soap is the most common treatment for mild infestations. See: Aphids for more information.
7. Leaves and stalks are partially defoliated, but no webbing
Grasshoppers, leafhoppers, or armyworms are the likely culprits. Armyworms are dark green caterpillars, they are the larvae of a spotty gray moth with a wingspan of 1.5 inches. Armyworms will group en-masse and are easily spotted, they eat all plants plant parts right down to the roots.
Handpick and destroy them. Grasshoppers need no introduction, you should know what they are and look like. there are a number of control methods available See Grasshopper Control.
8. Leaves turn from green to red
This is not harmful to beets. Some varieties naturally have red leaves, while others will turn reddish when the temperature drops.
9. Leaf margins turn red, leaf tips die; leaves become wrinkled; cracked roots with black spots
Boron deficiency. Test soil for deficiency . Maintain Soil pH between 6.0 and 7.0. See: Nutrient Disorders in Plants
Cracked roots and symptoms similar to boron deficiency can also be caused by inadequate watering. Keep soil evenly moist.
10. Brittle stalks, yellowed foliage, stunted growth, twisted and distorted plants
Aster yellows is the likely culprit. It is a disease spread by leafhoppers.
11. Tunnels in leaves, visible from the outer leaf surface
See Leaf Miners
12. Trails of shiny slime on leaves/foliage, leaves partially eaten
Snails and slugs are the culprit feed on leaves. Handpick from under boards set in garden as traps.
A shallow dish of beer will help curtail their populations.
13. Small round spots with light browning centers, edges are sometimes purple
The spots frequently fall out leaving holes in the leaves. Cercospora leaf spot is a fungal disease common where rainfall is heavy and temperatures are warm.
Pick off and destroy affected leaves. Keep weeds down in the garden area; they harbor fungal spores. Avoid overhead watering.
14. The leaves curl upwards, veins turn purple, growth is stunted
The leaves become thicker than normal and at times leathery. They sometimes crumble and the plant stops growing.
Curly top virus: spread by leafhoppers. Once virus has been diagnosed, remove and destroy all infected plants. Control leafhoppers.
15. Misshapen roots, poorly formed roots
Overcrowding; or poor soil quality. Thin beets early as possible. Remove any clumps and rocks from the growing area.
16. White rings inside beet roots
Drought or heavy rains during or just after hot weather can cause this. It is not harmful, however the flavor will be much stronger than usual.
Keep soil evenly moist , do not allow soil to dry out excessively after watering or rains.
Another very common problem with beets, as with all root crops is Grubs. The June Beetle is the most common culprit is most areas, but other grubs are also guilty. They feed on the roots, the plant growth is stunted.
Practice proper garden sanitation. Keep the garden clean and free of plant debris where adults can shelter and lay eggs.