Why Should You Identify Weeds?

How to identify lawn weeds. This lawn weed identification guide includes images, common and scientific names and descriptions to help you with weed id.

The guide is divided into three weed groups – broadleaf lawn weeds, grass weeds, and grass-like weeds – and then into sub-groups based on the plant’s life cycle.

Photos, names and short descriptions are included in this lawn weed identification guide – just follow the links to the individual weed pages where you will find more images, detailed descriptions for and weed control strategies.

Or…use the site search tool below to find weed information. Simply type the name of the weed and it will return all of the information found on this site.

A good Integrated Pest Management plan for controlling lawn weeds starts by identifying the problem weed and then learning about its life cycle. When you understand how the weed grows and reproduces, you will be able to decide the best way to manage it.

The presence of certain weeds are indicators of possible problems with your lawn. For example, prostrate knotweed grows and thrives in hard, compacted soils. Other weeds indicate your lawn is too wet, shady, infertile or thin. Identifying weeds and understanding how they grow will help you correct any problems with your lawn that encourage weed invasion.

Lawn Weed Identification – Three Weed Groups

1. Broadleaf Lawn Weeds

Weeds that are not “grass-like” are referred to as broadleaf weeds. Examples include dandelion, clover, and chickweed.

Annual broadleaf weeds – Have a life cycle that lasts only one growing season. From seed germination to flower blooms to seed.

• Summer Annuals – Seeds sprout in the spring as soil temperatures warm. They flower, seed and die – at the first hard frost – in the fall. They are also called warm-season annuals.
• Winter Annuals – Seeds germinate in the fall, they survive the winter, flower and set seed in the spring and then die as the temperatures warm. They can also be called warm-season annuals.

Perennial Broadleaf Weeds – Produce vegetative structures that allow them to live two or more years – roots or stems that survive the winter.

• Simple Perennials – These weeds can live two or more years but are unable to produce new plants from vegetative structures.
• Creeping Perennials – Weeds that can survive the winter (overwinter) and produce new plants from vegetative reproductive structures.
• Biennial Weeds – Complete their life cycle over two growing seasons. Seeds germinate and the plants form a rosette the first year. The rosette bolts (meaning it sends up flower shoots), flowers and produces seeds in the second year.

2. Grassy Lawn Weeds 

Grasses such as crabgrass, foxtail and orchard grass, that create an uneven look to lawns and take resources from the desirable grass.

• Annual Grasses – Complete their life cycle in one growing season. Crabgrass and annual bluegrass are examples of common annual grass weeds.
• Perennial Grasses – Are capable of living two or more years.

3. Grass-Like Weeds

• Sedges – Yellow and purple nutsedge are the most common sedges that are lawn weeds. These plants are “grass-like”- but they are not grasses – they are part of the sedge family.

Let Alan Jack’s Lawn Service help you out! Call us today! 661-213-6226