There's something going on with my beets, and I have no idea what it is. I can't tell if perhaps it's a leaf miner or maybe a fungus. They sprouted beautifully and began growing… There probably about 9 inches tall in places. But as you can tell from the attached photos, something is clearly going on with the leaves. Help? Thanks, Kerry
Thank you for attaching the excellent images of some nasty damage by leafminers. Leafminers are common pests of leafy greens, among them beets and spinach.
Leafminer larvae (youngsters) feed inside leaves and create either serpentine trails or, as on your beets, large blotches between the top and bottom leaf surfaces. Among the affected hosts which create the most angst for gardeners are leafy greens such as beets, chard, and spinach. Management in home gardens relies on cultural activities.
With an active infestation during the season, search-and-destroy is very effective. Crush the small white eggs on the leaf or squish the larvae inside their mines.
But next season, rotate those crops to a different area because leafminers spend the winter in soil as an inactive, non-feeding stage. Immediately after planting, protect the seeds, seedlings, or transplants with row cover, a non-woven “fabric” available at garden centers. (An alternative is bridal tulle obtained from a fabric store; it’s 72 inches wide, inexpensive, durable, and can be cut to the desired length.) Loosely blouse the cover to allow growing space for the plants. And then, to thwart the adult leafminer flies, anchor it at the perimeter with something heavy: a board, pole, or soil.
See “Leafminers” http://www.ipm.ucdavis.edu/PMG/GARDEN/VEGES/PESTS/vegleafminers.html and “How to Install a Floating Row Cover” http://cru.cahe.wsu.edu/CEPublications/FS089E/FS089E.pdf