New Weekly Word on Weeds from Dr. Joe Neal
Lontrel Update – Field Nursery Uses Allowed
Lontrel herbicide (active ingredient: clopyralid) has been labeled for controlling legume and aster weeds in turf and landscape settings for several years. Some of the susceptible weeds include clovers, sicklepod, hemp sesbania, vetch, eclipta, groundsel, horseweed, dogfennel, and thistles. It is generally safe when used as a directed spray around most established woody ornamentals but treatments near plants in the legume family, such as red bud, should be avoided.
The Lontrel label was recently amended to allow for use in nurseries; but, only in FIELD nurseries. Lontrel is very active in low concentrations on susceptible species. So, when using Lontrel, read and follow the instructions and precautions on the label. Some important precautions include:
Do not contaminate irrigation ditches or water used for irrigation
Do not use in greenhouses
Do not make broadcast applications to ornamental plantings; however, spot and directed applications are permissible
Do not allow sprays of this product to contact exposed suckers or roots of susceptible trees or shrubs as injury may occur
Do not collect treated grass clippings for mulch or compost
Do not apply to container grown ornamentals.
What does this mean to nursery crop growers?
Lontrel is another “tool” that field producers may use to control legume and aster weeds. It may be particularly useful in fields with a history of sicklepod, hemp sesbania or glyphosate-tolerant horseweed. Use it as a directed spray around woody crops only. But keep it off of actively growing foliage. I’ve seen significant injury on many broadleaf crops from directed sprays that contacted low hanging limbs (picture field grown hollies here). And, do not use Lontrel around red bud trees; plants can be damaged from root uptake of the herbicide.
Of course, read the label before you use Lontrel. This is a very good herbicide but a little bit of spray drift can cause significant damage to susceptible crops.
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
Showing posts with label herbicides. Show all posts
Showing posts with label herbicides. Show all posts
Monday, July 13, 2009
Herbicide Carryover in Hay, Manure, Compost
Herbicide Carryover in Hay, Manure,
Compost, and Grass Clippings.
Home gardeners and landscapers may feel they are doing the right thing, organically, when applying manure or compost to their gardens but- knowing something about the herbicides applied to the hay that the animals that produced the manure, ate can impact your choice of using the compost. The same goes for grass clippings of other plant debris that may end up in the compost. The attached article below describes the results being seen by many farmers and gardeners alike:
Herbicide Carryover in Hay, Manure, Compost, and Grass Clippings
Check your compost sources before using them!
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
Compost, and Grass Clippings.
Home gardeners and landscapers may feel they are doing the right thing, organically, when applying manure or compost to their gardens but- knowing something about the herbicides applied to the hay that the animals that produced the manure, ate can impact your choice of using the compost. The same goes for grass clippings of other plant debris that may end up in the compost. The attached article below describes the results being seen by many farmers and gardeners alike:
Herbicide Carryover in Hay, Manure, Compost, and Grass Clippings
Check your compost sources before using them!
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
Friday, April 3, 2009
Weekly Word on Weeds
Winter Annuals and Hand Weeding
Where did all that chickweed come from??? This time of year I look at my lawn and am surprised at how much chickweed there is in the yard. It didn’t seem like very much last fall or even just a month ago. But, when winter annual weeds begin to grow in the spring, they can grow very rapidly. AND, produce seeds for next year very quickly as well.
Now is the time to get the winter annual weeds out of the beds before they produce the bulk of their seeds for next year. Hand weed, spot spray with herbicides, hoe or shovel – regardless of the method you choose, do it now before they drop their seeds. Now is also the time to ask yourself -- “Why are these weeds here?” And, “what can I do differently next year to prevent these weeds”? Knowing that winter annual weeds germinate in the fall and early spring provides the opportunity to suppress or control them with a fresh lay of mulch applied in September or October. Where weed populations are heavy, a preemergence herbicide may be used in most landscape bed situations. Common herbicides containing pendimethalin (Pendulum & others), prodiamine (Barricade & others), trifluralin (Treflan or Preen), or isoxaben (Gallery, Snapshot & others) are labeled for use around many woody ornamentals. These herbicides control most winter annual weeds before they emerge. Granular formulations of trifluralin and pendimethalin can also be used around many herbaceous ornamentals. It is especially important to select the right herbicide based on the safety to ornamental plants. Horticulture Information Leaflet 644 (HIL644) provides some guidance for selecting safe and effective herbicides for color beds.
So, while you are spending this weekend hand weeding the beds, you will have plenty of time to think about what you can do differently next year to prevent all those pesky weeds from establishing.
Speaking of hand weeding – I have often said it is a futile effort to try and hand weed vetch. Typically, when you try to hand weed vetch, it just breaks off at the ground. But, the recent rains have provided an opportunity to control this and other hard to pull weeds. In wet soil, I’ve found that the vetch can be removed (yes, roots and all) if you grasp the tap root at the soil line and pull. The tap root comes up. Ok, not easily, but it does come out of the soil. When the soil dries out a bit more it is much more difficult to remove this weed, roots and all.
From: Dr. Joe Neal, Department of Horticultural Science, NCSU
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
Where did all that chickweed come from??? This time of year I look at my lawn and am surprised at how much chickweed there is in the yard. It didn’t seem like very much last fall or even just a month ago. But, when winter annual weeds begin to grow in the spring, they can grow very rapidly. AND, produce seeds for next year very quickly as well.
Now is the time to get the winter annual weeds out of the beds before they produce the bulk of their seeds for next year. Hand weed, spot spray with herbicides, hoe or shovel – regardless of the method you choose, do it now before they drop their seeds. Now is also the time to ask yourself -- “Why are these weeds here?” And, “what can I do differently next year to prevent these weeds”? Knowing that winter annual weeds germinate in the fall and early spring provides the opportunity to suppress or control them with a fresh lay of mulch applied in September or October. Where weed populations are heavy, a preemergence herbicide may be used in most landscape bed situations. Common herbicides containing pendimethalin (Pendulum & others), prodiamine (Barricade & others), trifluralin (Treflan or Preen), or isoxaben (Gallery, Snapshot & others) are labeled for use around many woody ornamentals. These herbicides control most winter annual weeds before they emerge. Granular formulations of trifluralin and pendimethalin can also be used around many herbaceous ornamentals. It is especially important to select the right herbicide based on the safety to ornamental plants. Horticulture Information Leaflet 644 (HIL644) provides some guidance for selecting safe and effective herbicides for color beds.
So, while you are spending this weekend hand weeding the beds, you will have plenty of time to think about what you can do differently next year to prevent all those pesky weeds from establishing.
Speaking of hand weeding – I have often said it is a futile effort to try and hand weed vetch. Typically, when you try to hand weed vetch, it just breaks off at the ground. But, the recent rains have provided an opportunity to control this and other hard to pull weeds. In wet soil, I’ve found that the vetch can be removed (yes, roots and all) if you grasp the tap root at the soil line and pull. The tap root comes up. Ok, not easily, but it does come out of the soil. When the soil dries out a bit more it is much more difficult to remove this weed, roots and all.
From: Dr. Joe Neal, Department of Horticultural Science, NCSU
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
Monday, February 23, 2009
Weekly Word on Weeds
This is the first article this season from Dr.Joe Neal, weed scientist with the Horticulture Department from NC State University.
With freezing temperatures still in the forecast it is difficult to think about summer weeds. But, now is the time to begin summer annual weed management.
First line of defense: Mulches
Before ornamental plants leaf out, and herbaceous plants emerge, this is also a good time to apply a fresh layer of mulch to landscape beds. Not only does this conserve soil moisture and improve the aesthetics of the beds, it also will cover and shade weed seeds to prevent germination and establishment.
When mulches are not enough:
Preemergence herbicides work by preventing the establishment of weeds from seed. That means the herbicides must be applied several weeks before weeds germinate. Apply preemergence herbicides now to control spring-germinating weeds such as crabgrass, spurge and oxalis.
Common herbicides used in landscape beds include Barricade, Pendulum, Surflan, and Snapshot TG. Each works on summer annual grasses (like crabgrass) but differ in how well they control broadleaf weeds. Generally, Snapshot and Surflan are better on broadleaf weeds; Barricade tends to excel on spurge, pendulum may be a little better on horseweed. These herbicides also differ in their safety to ornamental plants. Granular formulations of herbicides are safer on ornamental plants than spray applications. But, when applied before budbreak, liquid applications may be made over the top of most woody ornamentals. In herbaceous ornamentals, you must be careful in your choice of herbicides. See Hort Information Leaflet No. 644 http://www.ces.ncsu.edu/depts/hort/hil/landscape-index.html for more information on weed management in color beds.
Freehand – a new herbicide labeled for use in landscapes and nurseries:
Freehand is a granular combination of pendimethalin plus dimethenamid-p. It controls many summer annual weeds including crabgrass, oxalis, and spurge. It is one of the few herbicides that controls doveweed. It is also as effective as Pennant Magnum for the suppression of yellow nutsedge.
WWWeeds notes will be archived on my web site. http://www4.ncsu.edu/~jcneal/
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
With freezing temperatures still in the forecast it is difficult to think about summer weeds. But, now is the time to begin summer annual weed management.
First line of defense: Mulches
Before ornamental plants leaf out, and herbaceous plants emerge, this is also a good time to apply a fresh layer of mulch to landscape beds. Not only does this conserve soil moisture and improve the aesthetics of the beds, it also will cover and shade weed seeds to prevent germination and establishment.
When mulches are not enough:
Preemergence herbicides work by preventing the establishment of weeds from seed. That means the herbicides must be applied several weeks before weeds germinate. Apply preemergence herbicides now to control spring-germinating weeds such as crabgrass, spurge and oxalis.
Common herbicides used in landscape beds include Barricade, Pendulum, Surflan, and Snapshot TG. Each works on summer annual grasses (like crabgrass) but differ in how well they control broadleaf weeds. Generally, Snapshot and Surflan are better on broadleaf weeds; Barricade tends to excel on spurge, pendulum may be a little better on horseweed. These herbicides also differ in their safety to ornamental plants. Granular formulations of herbicides are safer on ornamental plants than spray applications. But, when applied before budbreak, liquid applications may be made over the top of most woody ornamentals. In herbaceous ornamentals, you must be careful in your choice of herbicides. See Hort Information Leaflet No. 644 http://www.ces.ncsu.edu/depts/hort/hil/landscape-index.html for more information on weed management in color beds.
Freehand – a new herbicide labeled for use in landscapes and nurseries:
Freehand is a granular combination of pendimethalin plus dimethenamid-p. It controls many summer annual weeds including crabgrass, oxalis, and spurge. It is one of the few herbicides that controls doveweed. It is also as effective as Pennant Magnum for the suppression of yellow nutsedge.
WWWeeds notes will be archived on my web site. http://www4.ncsu.edu/~jcneal/
For more information contact your local Cooperative Extension Center and ask for the Commercial Horticulture Agent.
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