I've had problems with gnarly wrinkled leaves on basil. This is separate from the other downy mildew. I had noticed this some on a few I had inside in the winter. Underside of leaf is somewhat pitted, not fleshy like the good leaves.
I've been trying new seed starts, trying to get around the mildew issue. Seeds sprout, then moved into 4" pots, outside, filtered into more sun as days go by. Look pretty, puffy, green etc. The start getting gnarly top leaves 1st. NO sign of bug, mildew etc. BTW, seeds from different sources, and use different bags of potting mix.
Yesterday took one to the garden center. They agreed something amiss. But, agreed no sign of bug or mildew. They hadn't seen this come through from other back yard gardeners. The closest guess they had was perhaps a virus, something we don't see.
I come up blank on the internet, but perhaps missing something. Any ideas?
That is from insects. Probably Thrips. They cause puckering of leaves and are common pests. They are very small so you will see damage before you see the thrips. Aphids are usually black and massed on the young leaves.
Thrips are ubiquitous and have many host plants. There are predators that will control them. You can use insecticidal soap or oil. Foil on top of the mulch will disorient them. Diatomaceous earth will also kill them, but it will kill other things too and it needs to be reapplied since it will not work once it gets wet.
Thrips are ubiquitous and have many host plants. There are predators that will control them. You can use insecticidal soap or oil. Foil on top of the mulch will disorient them. Diatomaceous earth will also kill them, but it will kill other things too and it needs to be reapplied since it will not work once it gets wet.