What Wha s Blooming? November December

Transcription

1 What s Blooming? November December

2 Largeflower Pusley Richardia grandiflora Stephen H. Brown Lee County Extension Et Southwest Florida

3 Richardia grandiflora,, alsoknownaslargeflower pusley or largeflower Mexican clover, is native to South America. It is a creeping herbacious (non woody) perennial, rooting at the nodes. It reproduces by seeds and stem fragments. Largeflower pusley tolerates temperatures as low as 10 F Phenology: Heaviest flowering is from September into January

4 While largeflower pusley does not appear on any of the Florida Exotic Pest Plant Council While largeflower pusley does not appear on any of the Florida Exotic Pest Plant Council (FLEPPC) lists of invasive plant species, in recent years it has definitely become a big problem in many south Florida lawns.

5 January, first year November, second year

6 Late November

7 Hairy branching stems

8 Leaves: Simple, opposite, narrowly elliptical, tapering sharply to points a both ends, with iha petiole

9 Flowers remain unopened in low light

10 Flowers: White, blue, pink or violet about 0.8 inch (2cm) long, clustered at tips of stems

11 The News-Press, Fort Myers, Florida November 26, 2011 Question: My neighbor has weeds all over his yard that are a mass of blue flowers. I have seen these weeds in many yards and lots. They have long runners. They are starting to invade my lawn and I would like to get rid of them. I have St Augustinegrass. What commercial product can I use? B.K., Answer: The weed is large flower pusley Richardia grandiflora This is a prodigious weedwith countless Answer: The weed is large flower pusley, Richardia grandiflora. This is a prodigious weed with countless numbers of white, blue, pink or violet flowers. Large flower pusley is native to South America and has adapted well to its new south Florida habitat, primarily St. Augstinegrass lawns. The herbicide used to control it is Atrazine or Image plus Atrazine. Atrazine can be found in liquid or granular forms. The liquid formulation gives much better control of large flower pusley and other weeds than the granular form. The former should have a 4.0% concentration. The latter, the granular form, is usually blended with fertilizer and sold as Weed & Feed. As a granular, the Atrazine concentration is usually less than 1%, not sufficiently concentrated to manage large flower pusley. Several applications, several weeks apart will be necessary for noticeable control. Do not use Atrazine when temperature rises above 88 F.

12 The News-Press, Fort Myers, Florida December 4, 2010 Question: For some years now it seems that the ground becomes covered with pink snow in the form of flowers this time of year. Whatever it is seems to favor lawns and is moving so fast that I m afraid it may soon reach my Floratam lawn. What is it, and how do we slow it down or get rid of it? Richard Messmer, Fort Myers Answer: There will be no getting rid of this weed that is now firmly established in south Florida. Richardia grandiflora, also known as largeflower pusley and largeflower Mexicanclover, isnative to South America. It is a creeping perennial with white, blue, pink or violet flowers. A lawn or field can have thousand of these flowers capable of dispersing tens of thousands of seeds. Controlling the spread of such a prodigious seed producer can be difficult. In a 2007 report, a University of Florida researcher found that none of the herbicides tested had a strong or lasting effect on largeflower pusley. Locally, however, repeated applications of Atrazine are said to provide good control. The effect of Atrazine will not be seen for at least a couple of weeks after application. This time of year, homeowners are largely confined to the use of Atrazine on their St. Augustine lawns. Another herbicide, Mansion, is sold at a few locations and is recommended for among other things, largeflower pusley control. The main problem with using Mansion is the small amount required per application. It should be measured precisely and applied uniformly or it can cause damage to lawns. Whether or not it will effectively control largeflower pusley is something I cannot positively confirm until herbicide trials are done using this product. It is recommended that Mansion be applied by a commercial landscaper. Read and follow label directions for all herbicides used.

13 Lawn and Garden Homepage Library of Native Plants Fact Sheets & Video Clips Christmas Senna Fact Sheet E mail contact Brownsh@ufl.edu 11/2011 & 12/2010