Can you name this plant - and help with infestation.

It's a Crown of Thorns. I have 2 but I'm obviously doing something wrong as mine have loads of leaves and I know they are meant to look like yours.

I can't help with the infestation.

I don't recognise the plant, but the infestation sounds like fungus gnats, which live in the dead vegetable matter in the soil around the plant. If it is a well-established infestation, there will be eggs and larvae in the soil, which replace the adults in a few days. You have to keep repeating the treatment until there are none left.

I have seen various cures, but it may take a while. Scrape off as much surface compost as you can and replace it. Spray the leaves with a bug-killer for indoor plants so that the plant itself draws it into its system and does its bit. Feed and water the plant so that it gets stronger, and don't let it dry out again - they prefer dry compost.

Put some left-over wine (drink the rest!) into a shallow dish and stand it nearby. The adults will go there to drink and drown. I have tried this and caught lots of them, and didn't see any more for some weeks, so it seems to work - but I repeated it as soon as I saw another.

I have also seen it recommended that you put a cut slice of raw potato on top of the compost, and the grubs creep up into it. The potato can be thrown away and a new slice laid down. I didn't find this worked, but maybe mine were fussy eaters.

I've just looked it up - its called euphorbia milii.

WE have suffered these in house plants a few times, very annoying. I have used Provado as a dip in the same way that i would for vine weevil. Dunk the whole pot for a few minutes.

We called it Christ-thorn in Kenya, and I heard it called Judas thorn elsewhere in Africa. Those thorns could be death to tyres!

I would cut it back if it has been stressed by drought. Then look after it.
Do be careful!
Euphorbias often exude a sticky white sap when cut. This sap can cause some people serious skin irritation.

I wouldn't it back unless you really have to - it takes years to get to that size!

I'd be reluctant to cut it back as it isn't mine.

Think I'll love bomb it. Lift it out of the pot and knock (gently) off what soil I can, add fresh compost and then try all the tips given above.
No wine, but I guess sherry or Tia Maria might be worth a try.

Thank you everyone, your responses have been really helpful.

I don't think it will be lacking water as they are desert plants as you said.

Harvey's Bristol Cream in situ !!

Do post a photo of the drunken revellers you catch!

Yes. I would take it out of the pot, wash it off thoroughly including the roots, then replant it in fresh damp compost. Then shut in another room so the little buggers can't re-colonise it.

Those irritating little flies are why I don't like house plants.

I don't get little flies on my house plants #famouslastwords!

Elegran just googled the phrase 'left-over wine' ...no hits. Was it a typo?

I've only got one house plant of my own, its' a 5' tall grape ivy and stands on the top of my nest of tables to give more height. I love it, wash it every 6 months. Pic attached.

Never had little flies before, that's why I believe they came with the plant when I was given it to look after.

Elegran - Update on drunken revellers: Only 2 bodies in 6 hours. DH reckons they don't party till later

I like the sound of Jings suggestion. Washing it, roots and all and fresh compost. Could lay it on its side on the garden table to work at it.

I've had those little flies in the past. It's why I don't go in for so many houseplants anymore. They are hard to get rid of for any length of time.

Google says it likes cactus/succulents compost. And some Babybio would encourage it.

Off to the garden centre with you.

How do you wash your plant, coolgran?

I have tried jings suggestion of washing off the whole plant outside under the hose. A Hoya it was, all sticky and covered in little flies coming out of the soil - but much easier to handle. I then left it outside for the summer in it's new compost to give it time to recover and for any stray flies inside to die off.

It then thrived and grew too big and I got rid of it. I only now have a very productive lemon tree indoors which is happy with dry soil. I wonder if it's damp soil which brings the flies in?

There is a specific cacti/succulent Baby Bio.

NfkDumpling Regarding damp soil, it was bone dry when it came to me 10 days ago. The flies definitely aren't 'coming in', it is in the porch and the window is shut. The flies appeared at the same time as the plant. We don't even use our front door - everyone uses the back door. My dil who asked me to look after it knows nothing about plants and it sat in her porch for several years with next to no watering. I have yet to ask her about her experience with the flies (if any). Will do so soonest.

thatbags It takes a good 60 minutes to wash my grape ivy. I stand it in front of me while watching something decent on tv. A packet of baby wipes or damp kitchen roll. Then I work my way methodically around the plant up and down, and around, leaf by leaf. Using a wipe to take off any dust and bin it when it's too grubby. At the same time removing any old/crispy leaves that might lurk towards the centre. There's a great satisfaction when it is all cleaned. Finish with a spray or two of leaf shine.

Jings I had a wee Google and saw that it liked cacti compost.

Kitty I've only got tomato food which I use for pretty much everything. Yep, a visit to the garden centre for food and compost.

If you ask your question in the Gardener's World forum you will get very helpful responses from the lovely people on there.