Search

Weed management in container plant production is a serious problem and remains one of the most expensive and time-consuming aspects of the plant nursery industry. Weeds compete for light, water, nutrients, and space, which ultimately results in decreased crop growth and yield. Weed management in container nurseries is primarily based on the use of timely preemergence (PRE) herbicides and supplemental hand weeding. The most challenging downside to applying PRE herbicides is often crop safety for many herbicide-sensitive crops commonly produced by Florida growers. Also, herbicide labels typically preclude application on bearing plants or for up to 12 months before fruit can be harvested. Due to these concerns, among the most commonly adopted non-chemical approaches to weed management in recent times is the utilization of mulch. This publication discusses best mulching practices, mulch types, application techniques, cost, and other management practices in container plant production.

The objective of this study was to evaluate the effect of weed placement on the growth of container-grown ornamental plants. Additionally, it also assessed the safety of applying herbicides beneath and on the slits of air-pruning containers using four common container-grown ornamental plants. The study was divided into three experiments, with uniform liners of pentas (Pentas lanceolata (Forssk.) Deflers) and golden dewdrop (Duranta erecta L.) in the first experiment and pentas in the second. The weed seedlings, consisting of either ageratum (Ageratum houstonianum Mill.) or eclipta (Eclipta prostrata L.), were positioned in one of three locations within the container, either directly beside the rootball of the ornamental plant, 2.5 cm away from the rootball, or inside the drain hole of the container. The third experiment involved four ornamental species, which were utilized to assess the safety of herbicide application either beneath or on the slits of air-pruning containers. The overall results of the first two experiments revealed that weeds growing either at the center or the sides of the ornamental plant rootball had significant competitive effects on the growth of the ornamental species. In case of the third experiment, no herbicide injury was observed on the ornamental species, with a minor decrease in the growth of loropetulam (Loropetalum chinensis ‘Ruby’).

Weed management in container plant production is a serious problem and remains one of the most expensive and time-consuming aspects of the industry. Weeds cause severe reductions in crop growth due to the limited growing environment characteristic of container plant production. The container nursery industry relies heavily on a limited number of preemergence herbicide options. The use of herbicides as the primary means to manage weeds has resulted in some negative consequences such as high chemical costs, leaching, runoff, and concerns with recycling irrigation water. Additionally, nursery growers are shifting their focus toward different nonchemical weed management strategies because many ornamental plants are very sensitive to preemergence herbicides. One such method is using organic mulch to control weeds in container plant production. Mulching is the foundation of a nonchemical weed management protocol and acts as the first line of defense against weeds. Organic mulches used in container plant production include rice hulls, pine bark, wood chips, wood shavings, coconut coir, nut (peanut, pecan) shells, oyster shells, cacao bean hulls, pelletized newspaper, recycled newspaper, pine straw, and other materials; material selection often depends on the availability of the product. The objective of this manuscript is to provide a comprehensive review of existing research on the utilization of various mulch materials as a weed management tool in container plant production. Additionally, it aims to highlight any critical knowledge gaps and provide suggestions for possible future research.

Plants inside our homes, offices, or those used as part of a patio garden have been shown to create a relaxed, productive environment and to improve indoor air quality. Overall, they are efficient, low-cost, and sustainable. While houseplants are safe to grow and provide many benefits, some can be toxic if ingested accidentally, which could be a concern for those with pets or small children. This publication is intended to inform homeowners, home gardeners, pest management professionals, and other plant enthusiasts of some of the most common poisonous plant species used as houseplants in Florida. It should be noted that while photos are provided of each species, there are many variations of each plant described, which could have different foliage color, variegations, slightly different leaf shapes, or flower colors.

Substrate stratification is a method of filling nursery containers with “layers” of different substrates, or different textures of the same substrate. Recently, it has been proposed as a means to improve drainage, substrate moisture dynamics, and optimize nutrient use efficiency. Substrates layered with larger particle bark as the top portion and smaller particle bark as the bottom portion of the container profile would theoretically result in a substrate that dries quickly on the surface, thereby reducing weed germination, but that would also retain adequate moisture for crop growth. The objective of this study was to evaluate the effect of stratified substrates on the growth of common nursery weeds and ornamental crops. This study evaluated the use of coarser bark (

This new 10-page publication of the UF/IFAS Environmental Horticulture Department is intended to inform home gardeners, pest management professionals, and other plant enthusiasts of some of the most common poisonous invasive plants or weed species common in home landscapes in Florida, with particular focus on species that could potentially cause harm if ingested. Written by Yuvraj Khamare and Chris Marble. https://edis.ifas.ufl.edu/ep631

Weeds are a serious threat to crop production as they interfere with the crop growth and development and result in significant crop losses. Weeds actually cause yield loss higher than any other pest in crop production. As a result, synthetic herbicides have been widely used for weed management. Heavy usage of synthetic herbicides, however, has resulted in public concerns over the impact of herbicides on human health and the environment. Due to various environmental and health issues associated with synthetic herbicides, researchers have been exploring alternative environmentally friendly means of controlling weed. Among them, incorporating allelopathy as a tool in an integrated weed management plan could meaningfully bring down herbicide application. Allelopathy is a biological phenomenon of chemical interaction between plants, and this phenomenon has great potential to be used as an effective and environmentally friendly tool for weed management in field crops. In field crops, allelopathy can be applied through intercropping, crop rotation, cover crops, mulching and allelopathic water extracts to manage weeds. Accumulating evidence indicates that some plant species possess potent allelochemicals that have great potential to be the ecofriendly natural herbicides. This review is intended to provide an overview of several allelopathic species that release some form of the potent allelochemical with the potential of being used in conventional or organic agriculture. Further, the review also highlights potential ways allelopathy could be utilized in conventional or organic agriculture and identify future research needs and prospects. It is anticipated that the phenomenon of allelopathy will be further explored as a weed management tool, and it can be a part of a sustainable, ecological, and integrated weed management system.

Substrate stratification is a new research area in which multiple substrates, or the same substrate with differing physical properties, are layered within a container to accomplish a production goal, such as decreasing water use, nutrient leaching, or potentially reducing weed growth. Previous research using stratification with pine (Pinus sp.) bark screened to ≤1/2 or 3/4 inch reduced the growth of bittercress (Cardamine flexuosa) by 80% to 97%, whereas liverwort (Marchantia polymorpha) coverage was reduced by 95% to 99%. The objective of this study was to evaluate substrate stratification with pine bark screened to remove all fine particles as the top strata of the substrate and determine its effect on common nursery weeds and ornamental plants. Stratified treatments consisted of pine bark screened to either 1/8 to 1/4 inch, 1/4 to 1/2 inch, or 3/8 to 3/4 inch, applied at depths of either 1 or 2 inches on top of a standard ≤1/2-inch pine bark substrate. An industry-standard treatment was also included in which the substrate was not stratified but consisted of only ≤1/2-inch pine bark throughout the container. A controlled-release fertilizer was incorporated at the bottom strata in all stratified treatments (no fertilizer in the top 1 or 2 inches of the container media), whereas the industry standard treatment had fertilizer incorporated throughout. Compared with the nonstratified industry standard, substrate stratification decreased spotted spurge (Euphorbia maculata) counts by 30% to 84% and bittercress counts by 57% to 94% after seeding containers. The shoot dry weight of spotted spurge was reduced by 14% to 55%, and bittercress shoot dry weight was reduced by 71% to 93% in stratified treatments. Liverwort coverage was reduced by nearly 100% in all the stratified substrate treatments. Compared with the industry standard substrate, stratified treatments reduced shoot dry weight of ligustrum (Ligustrum japonicum) by up to 20%, but no differences were observed in growth index, nor were any growth differences observed in blue plumbago (Plumbago auriculata).

The objective of this study was to determine how topdressing or incorporating fertilizer with stratified or mulched substrates could affect the growth of Hibiscus rosa-sinensis ‘Snow Queen’, a popular ornamental plant, and the growth of liverwort (Marchantia polymorpha) and bittercress (Cardamine flexuosa), two common nursery weed species. Five different substrate treatments were evaluated, which included three stratified substrates composed of pine bark screened to a small (0.63–1.27 cm), medium (≤1.90 cm), and large (0.96–1.90 cm) particle size and two industry-standard substrates that were either mulched with rice hulls or remained unmulched. All treatments were then fertilized via either topdressing or incorporating a controlled-release fertilizer (CRF). Bittercress control was highest in mulched containers, followed by those stratified using the medium pine bark, and its growth increased overall in topdressed vs. incorporated containers regardless of substrate or mulch treatment. All the stratification treatments resulted in a decrease in liverwort coverage compared to the industry standard treatment, but topdressing generally increased liverwort coverage compared with incorporating fertilizer. In conclusion, both topdressing and incorporation appear to be compatible with fertilizer placement methods with substrate stratification from a crop production standpoint; however, weed growth may increase if fertilizer is topdressed.

The objective of this study was to assess the growth of two woody ornamental plants when subjected to different levels of weed competition in four different container sizes, representing different stages of production. Ligustrum (Ligustrum lucidum W.T.Aiton) and Japanese holly (Ilex crenata Thunb.) liners were potted individually into 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. Weed coverage of 0%, 50%, and 100% in each container size was maintained by surface sowing seeds of six common nursery weed species by volume, based on media surface area in each pot. Results showed that the shoot dry weight of ligustrum at 50% and 100% weed levels was reduced by 28% and 35%, 55% and 56%, 41% and 43%, and 12% and 14% in 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. The shoot dry weight of Japanese holly at 50% and 100% weed levels was reduced by 18% and 22%, 51% and 52%, 51% and 53%, and 40% and 53% in 3.8 L, 11.4 L, 24.7 L, and 56.8 L containers, respectively. Results indicate that weed competition at 50% and 100% weed level was similar across all four container sizes, and weeds remained competitive even in the larger container sizes.

Torpedograss is one of the most invasive perennial grass species in Florida landscapes. This new 5-page publication of the UF/IFAS Environmental Horticulture Department was written for green industry professionals and others to aid in the identification and management of torpedograss in landscape planting beds. Written by Yuvraj Khamare, Candice Prince, and Chris Marble. https://edis.ifas.ufl.edu/ep615

Poison ivy is an allergenic plant of the cashew family native to North America. Poison ivy, poison oak, and poison sumac all grow in Florida and contain the oily resin called urushiol. This new 4-page publication of the UF/IFAS Environmental Horticulture Department was written to aid landowners, gardeners, horticulturalists, and pest management professionals in identification and management of poison ivy in residential and commercial landscapes. Written by Yuvraj Khamare and Chris Marble.

Benghal dayflower is listed among the world’s worst weeds, affecting over 25 crops in 29 countries (Holm et al., 1977). Benghal dayflower has many characteristics that make it a very troublesome weed in Florida landscapes, nurseries and other agricultural production areas. It was first recorded in Florida in 1928 and was designated as a legally noxious weed by the U.S Department of Agriculture in 1983 (Faden, 1993). Due to its status as a legally noxious weed, presence of benghal dayflower on nursery property can lead to quarantines, so identification and management is critical for nurseries. This 5-page article is written for green industry professionals and others to aid in the identification and management of benghal dayflower in and around ornamental plants. Major revision by Yuvraj Khamare, Chris Marble, and Robert Stamps, and published by the UF/IFAS Environmental Horticulture Department. Previous version: Stamps, Robert. 2011. “Prevention, Early Detection, and Eradication of Benghal Dayflower in Field Nurseries”. EDIS 2011 (5/6). https://journals.flvc.org/edis/article/view/119299.

Mulches have been evaluated extensively as a weed management tool in container plant production, but most research has focused on loose-fill wood-derived mulch materials, such as pine bark or wood chips. In this experiment, pine (mixed Pinus sp.) bark (PB), shredded hardwood (HW), and pine sawdust were evaluated for weed control and crop response both alone and in combination with a guar gum tackifier alongside a plastic film mulch, a paper slurry mulch, and the paper slurry mulch + PB and compared with a nonmulched, nontreated control and a single application of preemergence herbicide (oxyfluorfen + pendimethalin). Mulch materials were applied to nursery containers ranging from 7 to 25 gal at two different nurseries and at two research centers in central Florida in 2017 and 2018. Results showed that the plastic mulch provided more than a 90% reduction in hand weeding time and weed weight over a 6-month period, and similar control was achieved with PB, paper slurry + PB, and the HW treatment (64% to 91% reduction in weeding time and weed weight). No growth differences were observed with any mulch treatment in any species evaluated including ligustrum (Ligustrum japonicum), Chinese elm (Ulmus parvifolia), or podocarpus (Podocarpus macrophyllum).

The name tasselflower refers to two similar and closely related species, red or lilac tasselflower and Florida tasselflower. These species are very common in Florida nurseries, greenhouses, and landscapes. This new 6-page article was developed to help nursery growers, landscape professionals, and the general public identify tasselflower species, understand their biology, and provide information on ways to manage this weed. Written by Yuvraj Khamare, Chris Marble, Shawn Steed, and Nathan Boyd.

Praxelis is a newly emerging weed species in Florida, one that Plant Protection and Quarantine (PPQ) is considering adding to the federal noxious weed list. The plant can be easily misidentified and confused with Ageratum houstonianum (bluemink) and Conoclinium coelestinum (blue mistflower) as well as several other species that have similar flower characteristics. This new 5-page article is written for green industry professionals and others to aid in the identification and management of praxelis in and around ornamental plants. Written by Yuvraj Khamare, Chris Marble, Shawn Steed, and Nathan Boyd, and published by the UF/IFAS Environmental Horticulture Department. https://edis.ifas.ufl.edu/ep585

Doveweed is a common warm-season annual weed in Florida landscapes, container nurseries, and other agricultural production systems. This new 5-page article is written for green industry professionals and others to aid in the identification and management of doveweed in and around ornamental plants. Preemergence and postemergence herbicides are covered, as well as basic information on doveweed biology and growth. Written by Yuvraj Khamare, Chris Marble, Nathan Boyd, and Shawn Steed, and published by the UF/IFAS Environmental Horticulture Department. https://edis.ifas.ufl.edu/ep576

All eight species of Bidens in Florida are commonly referred to as Spanish needles or beggar-ticks. This document focuses on Bidens alba and B. pilosa, which are common weeds in container nurseries and landscapes in Florida. This 6-page EDIS publication, written by Yuvraj Khamare, Chris Marble, Shawn Steed, and Nathan Boyd and published by the UF/IFAS Environmental Horticulture Department, is designed for landowners, gardeners, horticulturalists, and consumers hoping to learn more about Spanish needle classification and management. http://edis.ifas.ufl.edu/ep572