clover-like weeds in potting mixture

[laurareeling]

I recently repotted 40+ orchids mainly to get rid of this clover-like weed which had taken over my plants. Today I find it again in one of the most recently repotted plants.

Does anyone know how to get rid of this stuff without repotting? It's pretty insidious and takes over quickly - trying to 'weed' the plant is time consuming and the surface stuff usually breaks off without getting the root anyway....

[dabblin-n-orchids]

if it is a relatively small plant (smaller than clover) and the leaves are more triangular than clover and it has no markings on the leaves it is probably oxalis. it is horrible and is extremely hard to get rid of. you are going to have to pull it up every where it pops up and what ever you do DON'T let is go to seed (seed pods look like tiny ocra) the old adage is seed one year weed seven.(and o lawdy is it true) I don't know of anything to do but pull it out, any herbicide that would kill it would probably harm your orchids . . .

[BikerDoc5968]

Dabblin is correct....sounds like Oxalis and it is nasty stuff. Just keep pulling it out as it grows and as has been said, the pods will burst open with the slightest touch and thousands of seeds will explode EVERYWHERE! Try to use tweezers and grab the little nasty close to its base and remove the roots....they grow very well even if you only remove the green "clover"

[Brooke]

Oh yes, nasty stuff. I like Doc's idea of the tweezers but try to grasp the plant just below the foliage where it goes into the root system. Also make sure the orchid media is very wet or the top portion will snap off leaving the roots, that then regrow the foliage.

Brooke

[Ray]

I's a really good idea to rid yourself of that, as the roots can suffocate your orchids.

I keep a Q-tip (artists' paint brush works too) and a small bottle of Round-Up herbicide in the greenhouse.

"Paint" the oxalis leaves and the plant dies without damaging the orchid.

[RosieC]

Oxalis... nasty?

I grow it as a flowering plant in my garden! It's really pretty and acts as great ground cover.

But I was warned when I planted it that I should only put it somewhere where I was happy for it to spread, because it's really difficult to get rid of once you have got it.

My Mum grows it as a flower in her garden as well, but her brother treats it as a weed in his vegtable garden.

Anyway, it has corms which it grows from and to have any hope of getting rid of it you need to try and get rid of those. They are quite mis-shapen corms though and if you are growing orchids in bark you could easily mistake them for pieces of the bark.

When I planted it I planted some small dead looking bark-like pieces with no roots or leaves and by the next spring they were coming up.

If you don't get up the corms it will always come back.