Hairy Bittercress

Scientific Name: Cardamine hirsuta

Other Names: Spring Cress, Shot Weed, Flick Weed, Jumping Jack, Peppergrass, Land Cress

Leaf Type: Broadleaf

Flowers: The flowers are small and delicate, with a diameter of about 1/8 inch (3mm). They will have four petals that are either white or pinkish in color, and they are arranged in a cross shape, similar to other plants in the mustard family. The flowers appear in clusters atop the thin stems, and they have a sweet fragrance that some consider to be quite pleasant.

Leaves: The leaves are small and thin, with a shape that resembles an arrowhead. They are light green in color and have a slightly hairy texture. The leaves grow in a rosette pattern at the base of the plant, with each leaf having a lone stalk that attaches to the stem. When crushed or torn, the leaves release a slightly pungent scent that some may find to be unpleasant.

Life Cycle: Annual

DESCRIPTION

This plant is a small and delicate herb that one might find growing in damp places like riverbanks or wet grasslands. It has tiny white or pinkish flowers that bloom in early spring and early summer. Its leaves are shaped like tiny arrowheads. It can be quite invasive and can quickly take over any area where it grows.

HOW TO IDENTIFY

Look for a plant with an upright stem no taller than 12 inches (30 cm) tall with bright green leaves that are shaped like arrowheads and grow in a rosette pattern at the base of the plant. At the end of the stem will be a tiny white or pinkish flowers arranged in a cluster. The flowers will be arranged in a cross shape, and they will have a somewhat sweet fragrance. Location also matters when identifying Hairy Bittercress due to their tendancy to grow on riverbanks, damp grasslands, and disturbed soils. Crushing the leaves should also provide a slightly pungent scent that some people consider to be unpleasant.

Mechanical Control Recommendations

Hand pulling
For small infestations, hand pulling can be effective. Make sure to grasp the plant at the base and pull it out, including the roots. This is best done when the soil is moist, as it makes it easier to remove the entire plant.
Digging
If the weed has established a more extensive root system, you might need to use a small gardening tool like a trowel to dig around the base of the plant and remove it along with its roots.
Mulching
Applying a layer of mulch around your plants can help suppress weed growth, including Cardamine hirsuta. A thick layer of mulch (2-4 inches) can prevent sunlight from reaching weed seeds, preventing them from germinating and growing.
Weeding Tools
There are various weeding tools available, such as hoes, weed pullers, and weeders with prongs, that can help you remove weeds more easily. These tools can be especially useful when dealing with larger areas.
Mowing
If the weed is growing in a lawn, regular mowing can help prevent it from setting seeds and spreading. Keep your lawn well-maintained to reduce the chance of weeds like Cardamine hirsuta taking over.
Tilling
For larger infestations in garden beds, tilling the soil can disrupt the growth of the weeds. However, this method can also disturb the soil structure and bring more weed seeds to the surface, so it's best used in combination with other control methods.
Prevention
The best way to control Cardamine hirsuta is to prevent its spread in the first place. Regularly inspect your garden and remove any weeds before they can set seeds. This will prevent the weed from reseeding and becoming an even bigger problem.

Pre-emergent herbicides:

Prodiamine: This is a commonly used pre-emergent herbicide that can provide control over a variety of annual grasses and broadleaf weeds. It is often found in products labeled for use on lawns and landscapes. Dithiopyr: Another pre-emergent herbicide often used on lawns and ornamental landscapes. It can target annual grasses and some broadleaf weeds. Isoxaben: This herbicide is often found in products that target broadleaf weed control in landscapes and ornamental beds. It can provide some pre-emergent control against certain broadleaf weeds. Oxadiazon: Used for pre-emergent control of both grassy and broadleaf weeds in certain settings.

Post-emergent herbicides:

2,4-D: This is a commonly used broadleaf herbicide that can be effective against a variety of broadleaf weeds, including Cardamine hirsuta. It’s often found in herbicide products formulated for lawns. Dicamba: Another broadleaf herbicide that is effective against many types of broadleaf weeds. It’s often used in combination with other herbicides to enhance effectiveness. MCPA: This herbicide is effective against many broadleaf weeds and is often used in lawn care products. Triclopyr: While typically used for woody plants and brush control, triclopyr can also have some effectiveness against certain broadleaf weeds. Clopyralid: Used for selective control of broadleaf weeds, and it’s sometimes found in products intended for use on lawns.

Selective herbicides:

2,4-D: This is a widely used selective herbicide that targets many broadleaf weeds, often leaving grasses unaffected. It’s often used in lawn weed control products. MCPA: Another selective herbicide effective against many broadleaf weeds in lawns. Dicamba: Dicamba-based herbicides are used to control broadleaf weeds. They are sometimes found in combination with other herbicides for improved effectiveness. Clopyralid: Used for selective control of broadleaf weeds and is often used on lawns. Triclopyr: While typically used for woody plants and brush control, triclopyr can also have some selectivity against certain broadleaf weeds.

Non-Selective herbicides:

2,4-D: A widely used selective herbicide effective against many broadleaf weeds. It’s often included in lawn weed control products. MCPA: Another selective herbicide effective against broadleaf weeds in lawns. Dicamba: Dicamba-based herbicides target a range of broadleaf weeds. They are sometimes used in combination with other herbicides for improved effectiveness. Clopyralid: Selective herbicide used to control a variety of broadleaf weeds in lawns. Triclopyr: While commonly used for woody plant control, triclopyr can also have some selectivity against certain broadleaf weeds.

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