Binomial Name: (Ambrosia artemisiifolia)
Ragweed or Hay Fever Weed belongs to the family “Asteraceae” of the Genus”Ambrosia", and its leaves closely resemble Artemisia. Ragweed is a persistent invasive herb that also exhibits the characteristics of a shrub in some of its growing climates. Ragweed is also a very competitive herb of the farm crops especially, soybean and corn, where it can potentially reduce production up to 30% that could go as higher as 47%. It also seriously invades ornamental landscapes and turf grasses in most of the North American climate. Ragweed is also associated with causing pollen allergies in humans. Usually, Ragweed succeeds in growing in full sun up to an elevation of 8000 feet in wastelands, ditches, and the areas along tracks and roadsides in different soil types.
Origin and Distribution
Ragweed has a wide distribution within the US especially, in tropical and subtropical areas including, North America, whereas its origin lies in northwestern Mexico and the southwestern US. Ragweed is also native to the central and eastern US including, Alaska and the Great Plains, the Caribbean, Argentina, Paraguay, Bolivia, and Brazil. Additionally, a north trend observes about its further migration. Ragweed is the utmost prevalent species of the Ambrosia genus in North America.
Ragweed-Identification
Ragweed is usually an erect plant with multiple branching patterns that can attain a height between 3 to 6 feet. The leaves are maybe 6 inches in length and up to 4 inches wide. Younger leaves look blue-green and hairy whereas, mature leaves are non-hairy. Stem color varies from green to light pink and sometimes even blue-green. Upper stems often contain one or more flower spikes. Ragweed produces several small and inconspicuous flowers which, initially remain green and turn yellowish-green when the seed is about to mature. Male pollens are wind-pollinated that often exist on the top of the same branch where female flowers are present. The pollens usually dissipate during late summer or early fall, and wind supports their migration to remote areas.
Ragweed- Propagation & Lifecycle
A single Ragweed plant produces almost one billion pollen grains that could remain airborne for several days, besides traveling long distances to target the hosts, especially, the people who are allergic to such pollens. The airborne capability of Ragweed pollens can make them travel up to 600 kilometers. Similarly, an individual Ragweed plant produces about 62000 seeds during one cropping year. Ragweed seeds, even buried in the soil surface could remain viable for five years or more and germinate upon receiving optimum growth conditions. Seed dispersal is also favored by pollinators, including birds and animals besides the wind. Ragweed seeds are somehow resistant to drought But grow well on medium moisture soil irrespective of the soil types and climatic conditions. Ragweed often produces a hormone that inhibits the growth of other plants where they succeed in growing.
Fun Facts About Ragweed
Ragweed- Prevention and Control
Cultural Control
Ragweed seeds produced in the same year can't sprout until they complete dormancy in the upcoming winter. Ragweed usually outcompetes turfgrasses in compacted and heavy soil for water, light, and nutrients. If the turfgrasses built thin stands, the competition more strongly suppresses their growth, and Ragweed appears to grow more dominantly than grasses. The only way to control Ragweed is to feed the lawns with fertilizers rich in nitrogen and potassium. Proper Mowing is also mandatory by observing the height that a particular grass variety needs. Also, increase core aeration in late spring and early summer because these are the best periods when turfgrasses can make a dense covering over the Ragweed.
Chemical Control
Control using Pre-Emergent Herbicide
Barricade-Granular Pre-Emergent Control
Barricade is a specialty herbicide that exceptionally controls Ragweed and other broadleaf weeds when they haven’t sprouted from the seed yet. Barricade contains 0.48% Prodiamine that is applied in early spring and fall. However, Barricade is not good at controlling Ragweed which, is already growing in the turfgrasses.
- Apply this product only in EARLY SPRING and FALL
- Barricade professional-grade pre-emergent weed control is designed to prevent weeds, and will not aid in eliminating existing weeds.
- Contains 0.48% of the active ingredient prodiamine - Labeled to prevent over 30 grass and broadleaf weeds
Applying and incorporating this granular formulation to a depth of 4 inches with a subsequent watering works well to stop germination from the seed. one 18 pounds ready to use product is incorporated in about 5500 to 6000 square feet of turfgrasses.
Control using Post-Emergent Herbicides
Sedgehammer Plus Turf Herbicide 13.5 Grams
The active ingredient in Sedgehammer is Halosulfuron Methyl (5%) which is meant for applying in established turfgrasses to control Ragweed and Nutsedge including, several other broadleaf weeds. Halosulfuron methyl belongs to the sulfonylurea group, and it inhibits the synthesis of an enzyme that stops further growth in Ragweed when applied. The absorption is both through foliage and roots, Whereas vigilant control may be possible in two weeks.
- 13.5 gram package Halosulfuron-methyl - 5% *
- Sedgehammer Herbicide is for use in established lawns, ornamental turfgrass, and landscape areas. Can also be applied in residential turf, other non-crop sites including: airports, cemetaries, fallow areas, golf courses, landscaped areas, public recreation areas, residential property, roadsides, school grounds, sod or turf seed farms, sports fields, fairgrounds, race tracks, tennis courts, campgrounds, and rights-of-way.
- Each 13.5 g packet makes 1 gallon of finished solution and already contains a surfactant. Each 1.33 oz. bottle makes 40 gallons of finished solution. Each gallon of finished solution covers approximately 1,000 square feet. In high volume broadcast applications, each 1.33 oz. bottle covers 1-2 acres.
A 13.5 g sachet makes one gallon of solution that can be applied over an area of 1000 square feet of turfgrasses. Halosulfuran Methyle is safe for most of the cool and warm-season turfgrasses.
UltraGreen-Weed & Feed Lawn Fertilizer
Weed and Feed Lawn Fertilizer is a dazzling mixture of three different types of herbicides along with fertilizers like nitrogen, potassium, Silica, peanut hulls, and limestone. 2,4-D, Mecoprop-p, and Dicamba acid are present in a ratio of 1.108%, 0.167%, and 0.071%, respectively. Which excellently control Ragweed and several other broadleaf weeds in turfgrasses. Moreover, it can be applied on most of the northern and southern grasses other than the Floral St. Augustine variety. Additionally, nitrogen and potassium trigger the growth of turfgrasses which, also suppress Ragweed and several other broadleaf weeds. The best application time is once in late spring and, secondly, at the start of autumn.
- Fertilizer and kills over 250 broadleaf weeds, including dandelion, henbit, dollar weed, White clover, plantain and chickweed
- Treats northern and southern grasses
- Not for floral St. Augustine
the product is in a ready-to-apply formulation, and one pack of 12.5 pounds can easily target Ragweed on 5000 square feet of turfgrasses.
Learn How to control and get rid of other weeds in our complete Yard Weeding Guide.