Oxalis? Pictures attached

Dave – posted 15 February 2004 13:21

I have 4 photos for you to see in order to help me identify these pesky weeds. http://f1.pg.photos.yahoo.com/ph/n4efdave/slideshow?&.dir=/Mail+Attachments&.src=ph

I live in Central Florida and have St. Augustinegrass turf.

I’d appreciate help identifying these two weeds that look similar and have thus far been resistant to my attempts to kill them.

I’d like a selective herbicide to apply, but it looks like RoundUp or Triox may be the only effective weapon.

The pictures are labled:

1. Oxalis -This is weed #1 (but is it really Oxalis?)

2. Weed clump – This is weed #2 — what is it?

3. and 4. are close-ups of the un-identified weed #2.

Thanks for your help.

Dave

ted – posted 15 February 2004 13:36

very catchy presentation there. oxalis has a yellow flower on it. this time of year, and this time of year only, you can spot treat with 24d type product and not harm the st. aug. you’re not suppposed to use 24d on st. aug. but it’s frequently done by pros on st. aug. in the cooler months of the year. don’t use roundup. spot spray only and follow label instructions.

scott – posted 24 February 2004 12:22

that looks like clover!

tommy – posted 24 February 2004 13:17

I don’t know what they are……but thats the best “f-ing” photography i have ever seen in my life!!

WeedDoc – posted 24 February 2004 14:57

I looked at your pictures and there are 2 distict weeds. The first is a type of Oxalis. The last 3 are white clover. Rounder leaves (not “heart-shaped”) and the whitish spot in the center are indicators that this is clover, even if you didn’t have the flower. Since it is flowering, the white “pom-pom” flowers are a dead give away. Any product, from a big box store or from a professional, containing the active clopyralid will knock out the clover in a heart beat. The wood sorrel (Oxalis) will also be affected by an application, but it would be best to yank it out and use fertilizers with preemergence weed control to keep your lawn heathly. A strong lawn is the best weed control.

ted – posted 29 February 2004 14:07

sorry- my computer didn’t catch the closeups the first time. yep, it’s clover- the last guy’s right a healthy lawn will keep this stuff out. mcpp + 24,d is the magic bullet on the clover-a regular spot spray of 24d will get the oxalis- been doing it for 20 years. watch for your temps- may be a little late to spot spray these chems on st. aug. – also- sharpen you mower blade! great time to fert. however…..

Dchall_San_Antonio – posted 04 March 2004 01:40

Clopyralid should be illegal to buy for homeowners. Actually it should be banned period, but I think it is illegal to buy unless you are licensed to spray it. The problem with it is that it persists for several years even after being eaten by a cow and the manure composted. Basically it turns composted manure into poison.

Another problem with all that persistence is that it tends to kill trees if the roots grow under the grass it is sprayed on.

And I agree with the healthy lawn keeping weeds out. White clover usually indicates a weakness in nitrogen.

Dave – posted 14 March 2004 11:41

Thanks for all of your kind replies. I’ve made repeated light applications of ORTHO’S WEED-B-GONE and another ORTHO product that also is specific for Oxalis and Clover.

Three applications two weeks apart were necessary to kill – it was slow, and the products did yellow the St. Augustinegrass a bit, but it will recover.

Thanks for the photography comments: my gripe with most “weed identification” photos on the web and in books is that they don’t recreate the homeowners weed-spotting experience.

Typically, I’m across the yard as I spot a clump of weeds. This should be the first type of photo, that is, a picture of “the forest”. Second, the next thing I do is inspect the weeds closely, and therefore, the next photo should be a close-up.

Thanks to all!

Dave