JUNE
2012

 

 

 

By
B. Rosie Lerner
 
Purdue
Extension
Consumer Horticulturist

 

Check out Rosie's book:Possum in the Pawpaw Tree

 

 

 

06-07-12

Question and Answer


Q. I have been trying, without success, to eliminate the wild violets from my yard. I have tried many different broad leaf weed sprays with no luck. They seem to be invincible! What can I use that is effective?

A. My yard also has a great population of both white- and blue-flowering violets, but I like them! I welcome their presence and look forward to seeing their lovely blossoms each spring. But I realize I may be in the minority on that.

Wild violets thrive where turf grass does not, usually in somewhat shady areas, such at the edge of a wooded area, under trees or where turf is thin from drought or other stress. Once they get started, violets establish colonies from thick underground stems called rhizomes; see photos at http://www.agry.purdue.edu/turf/weeds/violet/violet root.htm.

Wild violets are difficult to control, typically re-growing from pieces of rhizomes, despite attempts to dig them out or spray them with herbicides. And while violets prefer damp shade, once they are established they can tolerate sun and drought stress quite well.

If you just can't bring yourself to accept them, a broad-leaf herbicide such as triclopyr can be applied to the lawn, without harming the grass. But this herbicide can damage vegetables, flowers, shrubs and trees growing nearby if spray drifts their way. So be sure to read and follow all label directions. Generally fall (mid September - mid October) is the most effective time to apply broadleaf herbicides to the lawn -- that’s weed leaves are sending carbohydrate reserves to store below ground. But repeated applications are usually needed for tough species like violets; a follow up in June the following year may help and perhaps again the following fall.

evergreen
What's wrong with this evergreen tree?

Q. We have a beautiful 5-foot-tall evergreen in our front yard. Last May, I noticed the top of the main stem looked dead. So I cut back the smaller lateral shoots and left the largest to develop into the main stem, and it did. This year the same is happening. Do you have an explanation?

A. The photo appears to be a spruce, is that correct? It is odd that the same problem has happened two years in a row to just the very top; yet the rest of the plant looks quite healthy. At best, I can only offer some general guesses without more information and a closer look. It could be freeze injury, environmental stress, or an insect pest or disease at work. Though I would expect more than just the one terminal to be affected for all of those issues. It would be helpful if you submit a specimen to Purdue for a closer look at the dead terminal branch. The Purdue Extension office in your county may be able to help diagnose, but can also assist you with submitting a sample to the Purdue Plant and Pest Diagnostic Lab if needed. You can find information and a submission form on the PPDL website, http://www.ppdl.purdue.edu.

mystery plant
What is this mystery plant?

Q. Enclosed are two photos (attached) of my mystery plant. What is it? The local nursery did not know it. They guessed maybe a tropical, because of the look of the trunk.

The plant started as a volunteer seedling among my plants with begonias. I bought the begonias in a six-pack. I decided to remove the seedling and pot it separately to see what it was. I love to experiment with unknown seeds or plants. Can you shed some light on what this plant is?

 A. It is difficult to say without the benefit of seeing more detail, but it does look like it could be one of the ficus (fig) species. Most figs have a white, milky sap in the leaves and stems, so it would be easy to check for that. (Beware that some people have skin sensitivity to the latex in the sap.) There is a cultivar of edible fig called Ice Crystal that has similar-shaped leaves. But juvenile leaves from seedlings can look different from the mature plant. And there are many species and cultivars of closely related figs. Seedling figs do not fruit reliably, but it could make an interesting ornamental plant.

 

Writer: B. Rosie Lerner
Editor: Olivia Maddox,