Rob Leeds: Plant sale this weekend at fairgrounds

Rob Leeds - OSU Extension

Come on out to the Delaware County Fairgrounds for our annual master gardener plant sale this weekend, July 23 and 24. You will get some great prices on shrubs, trees, perennials, annuals and much more.

The sale will be at the Delaware County Fairgrounds in the Pig and Lamb Barn Saturday from 9 a.m. to 3 p.m. and Sunday from 6 a.m. to 1 p.m. Those of you who have come to our plant sale in years past know what great deals you can get to spruce up the yard and flower beds. If you have not been to one, be sure to come check it out.

Proceeds go to further the mission of the Delaware County Master Gardeners, which is to educate others with timely, research-based gardening information.

Do you have some problems with plants in your vegetable or flower gardens? Some of your trees not doing as well as they should be? Call our master gardener help line at 740-833-2030. Our master gardeners offer a help line during the growing season. This is open to residents in the Delaware County area who have questions or requests for information on lawn and gardening questions.

You can bring samples into our office at 149 N. Sandusky St. from 8:30 a.m. to 4:30 p.m. Monday through Friday. Or if you have a smart phone, take a picture of the problem area (along with a full view of the total area) and email it to A master gardener will do research and get back to you either by phone or email. No question is too small or too large.

According Jim Noel of the National Weather Service, the forecast is looking like the remaining part of July will be overall hot with rainfall at or below normal, with August warmer than normal. Rainfall is looking like it will be closer to normal but the data suggests we will more likely be on the drier side of normal.

Much of the corn and soybean belt is in good shape with rainfall and temperatures. The exception is northern Indiana into Ohio which seems to have some of the driest areas. We have been are pretty fortunate in Delaware County. Other areas to our north and northwest are very dry. Most of the research indicated yields this year would not be as good as the last several years, including Ohio. It also appears we will see the hottest temperatures of the season early this weekend with highs in the 90s and lows in the 70s. The two-week NOAA/NWS/Ohio River Forecast Center rainfall pattern indicates rainfall will range from 0.50 to 2 inches.

The month after wheat harvest provides an opportunity to control marestail and prevent further increase in the soil seedbank, but coming up with the right strategy has not necessarily been easy.

According to Mark Loux, OSU Extension specialist, the primary goal of marestail control here is preventing seed production, which doesn’t mean that any treatment applied has to provide 100 percent control of the plants themselves. OSU Extension has conducted several studies targeting tough marestail situations, representing plants that have been previously treated with herbicide or mowed, or survived tillage, and also one study in a wheat stubble situation. The reason all of these studies are important is that there can be a couple of different types of marestail plants in wheat stubble. The generally easier plants to control are those that are small and have lurked within the wheat, below the height of the cutter bar.

Loux says that these plants grow taller in response to light once the wheat is harvested, but are free of prior damage that would make them more difficult to control. The other plant type is the one that was tall enough to be cut off by the cutter bar, and these also regrow following harvest, but the prior stress makes them much more difficult to control. And, of course, there can be emergence of new plants after harvest, depending upon moisture and the degree of soil cover by residue.

A few things Loux says that we have learned relative to this situation:

• The goal of preventing or greatly reducing seed production can be accomplished without herbicides. Mowing is effective and can be timed for the early flower stage, before plants have produced seed, and late enough that substantial regrowth and potential for much additional seed is low. Downside is that it is more time consuming than herbicide application. And, of course, tillage can work here, too.

• If both mowing and herbicides are going to be used, Loux suggests using herbicides first and follow with mowing later, as needed. Trying to control plants that have regrown after mowing will be difficult.

• With regard to herbicide treatments, earlier is better. Some regrowth of damaged plants is fine, but allowing plants to get larger almost always reduces control and may require a more comprehensive treatment. In a 2014 wheat stubble study, Loux applied herbicides on either July 25 or Aug. 7. These were mostly plants that had not been damaged by the wheat harvest. The combination of glyphosate plus 2,4-D applied on July 25 provided 85 percent control and resulted in only few plants being able to produce seed. All other treatments, which included Sharpen, Liberty dicamba, etc, provided 100 percent control. When application was delayed until Aug. 7, control with glyphosate plus 2,4-D or dicamba dropped to 70 to 74 percent and 38 to 43 percent of the surviving plants produced seed. Control with dicamba plus 2,4-D also was reduced to 78 percent, but plants did not produce seed. The other treatments still provided upwards of 85 percent control and prevented seed production. Loux suspected that the difference in control between application dates would have been accentuated for marestail plants that had been damaged by the cutter bar and regrown.

• Some growers try to apply late enough in summer to control both marestail and volunteer wheat. This is likely to make control of marestail difficult. The post-harvest treatment is also not likely to serve the purpose of controlling marestail plants that emerge in late summer into fall. A mid- to late-fall application will still be most effective for those.

• In the other studies where they were trying to control marestail plants that had undergone a previous stress (such as cutter bar damage), it was difficult to obtain greater than 80 percent control with any treatment, and Loux said that it rarely killed more than 10 percent of the plants. The study did not follow surviving plants through to maturity to determine effect on seed production. The more effective treatments tended to be combinations of more than one herbicide that had activity on marestail (excluding glyphosate), such as glufosinate plus 2,4-D or Sharpen. Overall, the variability of control increases and predictability of effectiveness decreases for plants that have regrown following damage or prior treatment, and allowing them to get taller does not help.

Rob Leeds

OSU Extension

Rob Leeds is the Ohio State University Extension educator for agriculture and natural resources in Delaware County.

Rob Leeds is the Ohio State University Extension educator for agriculture and natural resources in Delaware County.