are these indoors.. outdoors.. where are you.. whats the weather been ...

fall mildews are not uncommon ... outdoors.. not preferred indoors.. lol ...

more info plz.. and perhaps pix of the whole plants ...

where are you .. big city name ... many of these annuals go into decline in fall.. due t]o the declination of the sun ... especially thru windows ... and indoor perennials are that much different ...

ken

Hi Ken!

I live in London, the weather has been sunny and humid (around 21 - 30 degrees) for about 2 months now, up until September, where things have started to cool down a bit.

I keep my herbs in a small greenhouse in my garden:

As for pics of the whole plant, I sadly threw away a lot of my mint yesterday to try and curb the infestation/disease, but here's a pic of the cuttings. It's hard to see the damage but try and zoom in.

Here's the oregano:

Hope that helps, and thank you 😊

Hi Tamara. Step one is to get them out of the greenhouse. Both are perennial and completely hardy outdoors where you are. Being under plastic will just encourage pests and diseases. With no natural wind or rain to battle against bugs will thrive, and in the closed humid environment fungi can take off. Plus even transparent plastic blocks light. Set your Oregano in the sunniest spot you have. If you can put it in the ground rather than in a pot that’s even better. The mint can take a little shade but in our climate full sun is fine for that too. However, mint spreads so it’s probably better to keep it in a spacious container. Mint may well remain evergreen in London (Croydon?) but it will produce fresher growth if you cut it down occasionally. Usually just harvesting it is sufficient. The Oregano is evergreen and you can harvest year round.

I notice you also have rosemary. That too needs to be out of the greenhouse in as much sun as possible. It is fully evergreen and usable all year round.

Hiya! Yes I'm based in Croydon, I'll look for a sunny spot in my garden to put the herbs, thanks for the tips!! Unfortunately I don't have space to plant it in the ground, otherwise I definitely would!

Haha I figured 😂

I think i've figured it out! They're thrips. I bought some organic compost in August and used it to repot all of my herbs, which explains why all of them have the same look and black dots on the leaves.

I wet a handful of fresh compost from the bag I bought in August and little thrip larvae started to crawl to the surface.

I wish I'd discovered this earlier because I just added a layer of compost to my avocado tree and now I'm worried I've destroyed it, because I've seen some thrip larvae in there too now.

Any tips on how to get rid of them? Or how to sterlise the soil? I've heard insecticidal soap, neem oil, kaoloin clay and diatomaceous earth are good.

I think you’ve probably found some US sources of information since none of those is an accepted pesticide here. Neem is actually illegal. Kaolin is unlicensed. DE washes off in rain and is only sold for indoor use. Afaik insecticidal soap is only available online and I’m not sure of its status.

If you get the plants out of the greenhouse they’ll improve just through fresh air, wind, rain and sun. You can trim off the worst bits and try to accept a bit of cosmetic damage. If you still need a remedy go to a reliable resource written by experts for conditions in this country https://www.rhs.org.uk/advice/profile?pid=876