My basil is "rotting", here's all the clues I have gathered

Question

This is my third try in having a basil that lives more than a month and I've been rather successful with my last try. But now, for some unknown reason to me, it's dying.

Here are many pictures of what I have gathered and my comments to help you understand and, hopefully, help me understand and overcome this situation. I've found many basil related questions on this site already but they didn't seem to have the same symptoms (most of the time, basil was being eaten by something, mine seems to not lose matter, but to rot instead).

Image 1: These are the stages of the process. From left to right, healthy to dead. The last one is completely dry and often falls off just by barely touching the branch.

Image 2: I've had to cut leaves regularly as they became more and more infected, and cutting infected leaves seemed to slow down the infestation of the remaining leaves. All of them seem infested now.

I think it happened from bottom to top, since only the top leaves are now alive, but they are also the last ones to have been growing so I don't know.

You can also see in the background I'm using a fertilizer to help nourish the plant, as the last two basils I've had died, I'm just trying to boost my chances.

==== Here are some close up shots to help you gather more information ===

======= End of close up shots ======

This image should help you grasp the size of the current plant. This is the largest basil I've ever grown, I think because I started in May and not because I'm a "good gardener".

And now the most important bit and maybe what I should've started with

• These white crawling insects are all over my plant.
• They do not seem to grow.
• They don't seem hairy.
• They're about 1.5mm long, but I've eyeballed it

I can find them inside/under leaves, and that's about it. I've seen them in the dirt but I think its just from the leaves falling. They're now on my table from all the dead leaves I've removed.

I've also found a very small spider, I have no idea if she's related either. I'm hoping she's enjoying all the food, but I don't think she can eat all those bastards alone.

Okay, I know that's a lot of pictures, most of them are probably all irrelevant, but since I have no clue I'm trying to provide as much information as I can.

Oh, also, I live in Belgium, summers are not really hot here but there can be 10° (Celsius) differences in a single day. The plant is inside, always watered from the bottom. That window right next to it is pretty much always open, and the plant is exposed to direct sunlight about 1h or 2 at least every sunny day.

Please ask me for more information if you need it. I'm not sure what I can do for my next basil since this one will probably be dead in the next few weeks.

Answer 1

Looks like a heavy whitefly aphid infestation - they're usually underneath the leaves and suck the sap within, causing the leaf to shrivel and die. You can't treat with pesticide because it's an edible plant, so your only recourse is something like neem or insecticidal soap spray, I'm afraid. Further information on how to deal with whitefly on edible plants here http://homeguides.sfgate.com/kill-whitefly-basil-plants-killing-plant-40658.html

Answer 2

The leaf damage you are seeing is almost certainly thrips feeding damage, though it does not look much like the first reference here. For your next plant, you may want to replace the soil and clean the pot well (thrips can survive in soil). These may provide some places to start looking for a solution that will work for you.

http://mtvernon.wsu.edu/path_team/basil.htm#thrips

http://ipm.ucanr.edu/PMG/PESTNOTES/pn7429.html

Answer 3

You've got major insect infestations and a beat up plant. I would sadly get rid of that plant and the soil. Disinfect the pot with a bit of bleach. Get another basil plant and use only potting soil. A little Osmocote

I would try THAI BASIL. Knock you down dead with the flavor and smell! I dried mine filling 3 gallon size ziplocs last season. Working on growing more because we are out and no other basil is this good, my opinion of course!