How to Identify and Control Summer Lawn & Landscape Weeds

summer annual weeds

In the world of weeds, there are weeds that are around all the time such as perennials, and then there are weeds that only show up for a short time, also called annuals. Both life cycles can be frustrating when trying to control them and perennials are usually more difficult to eliminate.

Many perennials have deep or extensive root systems that make hand pulling an almost futile effort. Annuals, since they only live a short time, can usually be pulled out and disposed of, but they often leave behind hundreds if not thousands of seeds, waiting for the right temperature and moisture levels to start growing again.

Types of Annuals in your Lawn and Landscape

There are two types of annuals: winter and summer. Winter annuals germinate in the fall, over winter in a vegetative state and then start growing again in the spring. In the warmer parts of the country, winter annuals continue to grow throughout the cooler winter months. At the end of their life cycle, winter annuals will flower, produce seeds and die with the heat of the summer. Summer annuals germinate in the spring, grow leaves, produce a flower, seed head and then die with the cooler weather of fall. We are amid the summer annual season.

All soils contain seeds of various plants, which are mostly weeds. Weed seeds can germinate even after being underground for many years. If you have ever weeded your garden and removed all the weeds that were growing there, in just a few days, a whole new crop will begin to emerge. Keeping weeds under control in a garden is an unending chore.

Using mulch is a great way to keep weeds under check, but even it must be maintained on an annual basis. This means adding fresh mulch every year. A three-inch layer of mulch will keep weeds down and provide nutrients to the plants growing in the garden as the mulch decomposes. If not maintained, in a year or so, the mulch will be covered in all types of weeds.

Summer Annual Weeds

Probably the most notorious summer annual is crabgrass. This hated summer annual grass type weed will germinate as early as February in the South and as late as July in the North. Each crabgrass plant can produce several thousand seeds that are left in the soil to germinate again next year. There are weed control materials that help to prevent crabgrass from germinating. There are newer weed control products that will selectively control crabgrass without damaging the desired turf grass. Crabgrass can be hand-pulled, but often, the population is so great that this would be a daunting task.

There are many broadleaf weeds that are summer annuals. Some are mainly in the South, such as Chamberbitter, while others are more universal, such as Oxalis, Spurge and Knotweed. For the most, these weeds can be easily controlled with most commercially available weed control products. Be sure to read the product label before using and make sure the product will only kill broadleaf weeds without damaging your lawn.

If weeds are a problem in your lawn, contact your neighborhood lawn care professional at Spring-Green. They can work with you to get your weeds under control and help create a healthy better looking lawn.

If You Had a Dollar for Every Dollar Spot On Your Lawn…

Dollar Spot Lawn Disease

You probably wouldn’t be rich, but you might have enough for a decent night out. We’re speaking, of course, about Dollar Spot, the lawn disease that cheapens the look of your lawn. This lawn disease can infect almost all cool-season and warm-season turfgrasses, including Bentgrass, Fescues, Kentucky bluegrass, Perennial Ryegrass, Bermudagrass, Zoysiagrass, Centipedegrass and St. Augustinegrass.

Development of Dollar Spot Lawn Disease

If conditions are right, the disease can develop on most any lawn, but a well-maintained lawn will recover from the damage faster than a lawn that does not receive the proper cultural practices for mowing, watering, fertilization and thatch control.

The conditions for Dollar Spot development include:

• Air temperatures from 60-90°F (most active at 70-80°F)
• Extended periods of high humidity, especially at night
• Most damage occurs when days are warm, nights are cool and dew is present for more than 8 hours
• Lawns that have low nitrogen fertility levels

Symptoms of Dollar Spots start with the development of fungal growths called mycelium, which invade the grass blades. On low cut grasses like bentgrass or Bermudagrass, the mycelium will form small, silver dollar sized spots, which is where it gets its name – Dollar Spot. On higher cut grasses, the patches are larger and can merge to form large blighted areas of turf.

The mycelium forms early in the morning and will often dry out as the sun rises in the morning. It will leave behind a definitive hourglass-shaped lesion on the grass blade that has a reddish brown border. In some cases, the leaf blade will turn a tannish-white color from the tip down, but it almost always has the reddish brown border between the damaged part of the leaf tip and the remaining green part of the blade.

Prevention and Treatment for Dollar Spot

Treating Dollar Spot requires following proper cultural practices. At Spring-Green, we develop a partnership with our customers. We rely on them to water during the morning hours and to water deeply, but infrequently. Mowing is also critical in preventing Dollar Spot development. Every turfgrass has a range of heights at which to mow.

During the late spring and summer months, mow at the highest recommended height for the turfgrass in your lawn. Another important practice is to core aerate your lawn every year. Core aeration will help improve root growth, which leads to a stronger lawn.

By following Spring-Green’s Preferred Lawn Care Program, your lawn will receive the proper amount of nutrients to develop a healthy lawn that can resist or recover from disease pressures. There are disease control materials available to help prevent Dollar Spot from developing and Spring-Green can apply those treatments if the disease is observed early on.

In most cases, a healthy, Spring-Green lawn will survive and recover from a minor disease infestation. Contact your neighborhood lawn care professional at Spring-Green to help prevent Dollar Spot from developing on your lawn and landscape.

Anthracnose: Leaf Infecting Fungi

anthracnose

Many parts of the US experienced a very wet spring. Some areas also had to deal with cooler than normal temperatures making it prime conditions for leaf-infecting fungi. The results of the infections caused by these fungi are noticeable now, as leaves begin to fall or the leaves which are still on the trees are showing spots or lesions. These lesions often form along the leaf veins or on the edge or margins of leaves and can range in color from tan to reddish-brown to black.

The cause of these spots are from a group of fungi collectively called anthracnose. The disease can infect numerous tree and shrub species including Maples, Oaks, Sycamores, Ash, Birch, Viburnum and several other species. The symptoms include leaf spots and lesions, shoot blight, cankers on twigs, limb dieback and almost entire defoliation of the plant.

In many cases, even with defoliation, anthracnose does not cause permanent damage to the tree. Sycamores are one tree that can lose almost every leaf in late spring to early summer due to the disease and it will regrow a new set of leaves. This does put stress on the tree, but unless it happens several years in a row, the tree can recover from its loss of leaves.

Preventing Further Outbreaks

As with many foliar diseases, one of the keys to preventing further outbreaks is sanitation. This means raking up and disposing of infected leaves. The fungi overwinter in leaf buds, twigs, fruit, fallen leaves and even the leaf stems, or petioles, depending on the type of anthracnose fungi found on the tree.

The disease cycle begins in the spring during cool wet, weather with most activity peaking when temperatures are in the 50-70°F range. The spores from the previous year are dispersed short distances by water or long distances by the wind. The infection stage begins as the leaves are beginning to open in the spring. If the weather conditions remain or become cool and wet, the disease can re-infect the same plant in the summer. The cycle ends when the weather dries and the leaves mature.

Treatment for Anthracnose

For the most part, anthracnose has more of a cosmetic effect than permanent effect on most trees. If the tree is healthy and well-cared for, it can defend itself against anthracnose. Maintaining good tree vigor is important, which includes watering, adequate fertilization, mulching and proper pruning.

Many people fail to water their trees during drought periods. This is especially important on recently planted trees. Removing the grass from around the base of the tree in a circle of about 3 to 4 feet and replacing the grass with a 3 inch layer of mulch will provide numerous benefits to the trees and avoid possible trunk damage from lawn mowers and line trimmers.

Spring and fall fertilization is also very beneficial to the health of all your landscape plants. There are disease control materials that can be applied very early in the year as the buds are open, but this is not usually required unless the plant experiences the same problem with anthracnose every year.

The best thing to do is to have your landscape evaluated to determine a program that is the most beneficial for the health of your plants. Contact your neighborhood Lawn Care Professional at Spring-Green to have your landscape evaluated for disease and insect problems and receive a program that will help produce healthier landscape plants.