Oxalis Corniculata aka creeping woodsorrel how to kill in a new lawn ?

Merlin_3

Hi,

seeded the cleared area 40 or so days ago, used Johnsons shady place as its under a cyprus tree, after 3 weeks I saw a hint of green, its now 3 or so inches tall, BUT there is an area of solid Oxalis Corniculata like looking down on a forest and elsewhere the new grass has this in amongst it and no doubt in time I will have a lawn of OC not grass ! My gut feeling is the area whilst surface cleared was not dug out deep enough and breaking the plant up has just caused it to reappear if its a young version of a plant that was there before but was a dull purple colour nothing like this bright fresh green colour. I was not present whilst it was being cleared of surface vegetation and seeded.

What is the best way of killing this so that I dont kill my newly growing grass and see a new lawn there else weeks of effort are all wasted, as I have yet to have that area mowed so the OC leaves are new and young and intact and no stress yet on the new grass roots.

Merlin_3

so is this plant impossible to kill then ?

the weed from hell ?  no replies says so.

I am new to gardening and I cant even find anyone that knows how to solve Oxalis in NEW LAWN.

I have sprayed it with 3x the strength one should do of liquid chelated iron, some have wrinkled, BUT I ALSO SEE ONE WEK OR SO ON THAT I HAVE NEW GROWTH and thats without touching the area at all, so no broken bits into soil to sprout new plants. But now the area needs mowing, so what do I do as this NEW LAWN is lost to this weed from hell. so one cant say replant the area as it is replanted !

Please someone must know how to kill this thing.

gardenersworld.com sounds like a knowledgeable site.

treehugger80

cut your lawn normally till it gets cold and use weed and feed in the spring, be prepared to resow any areas that have bald patches

AnniD

Oxalis is an absolute bu**er to get out of lawns (or flower beds come to that). I speak from experience, trust me. When the lawn is established you can rake it out , so l feel for you having it in a newly sown one and having to wait.
Wyevale's site says this
Good lawn care. Unfortunately creeping woodsorrel is more difficult to control in lawns as it is resistant to all lawn weedkillers. The best thing you can do is to keep your lawn healthy and well fed, which will improve the turf and leave no room for invasion. If creeping woodsorrel does make an appearance, vigorous wire raking in early autumn will get rid of most of it, but heavier infestations may require complete removal of the turf and reseeding.

You may just have to bit the bullet until Spring as treehugger says, maybe @glasgowdan can offer some help.

glasgowdan

It's one reason why it's always advisable to clear an area, rake out and then wait 4 weeks to allow weeds to grow before doing a full blanket glyphosate treatment a week before seeding. 

I wouldn't guarantee killing it with any professional lawn selectives, but I'd also wager it being drastically depleted with a 2x treatment in the spring, 4 weeks apart, with one of the more complex versions available. 

madpenguin

I have this all over my garden and in my lawn but I have never found it to be a problem.
Such a pretty flower!

Lizzie27

I've got it too but have been trying to get rid of it, it's too near the lawn for my liking. Very persistant though!