Underground Stems: Identify & Control Them NOW!

Unwanted growth in your garden can often be traced to underground stems. These sneaky structures, technically known as rhizomes, can allow invasive plants like Bermuda grass to spread rapidly and are difficult to eradicate. Effective control hinges on proper identification and understanding of the specific plant. Strategies recommended by the Extension office often involve methods such as diligent hand-pulling and targeted herbicide application but must be tailored to the species. Furthermore, recognizing persistent weeds spreading via underground stems is key for any gardener aiming for a healthy and thriving landscape.

Decoding Underground Stems: Identification and Effective Control

Underground stems can be deceptive. They often look like roots, but they’re a key factor in the rapid spread of certain plants, some of which may be invasive weeds. This article will help you identify underground stems and provides practical strategies for controlling them.

Understanding Underground Stems

What are Underground Stems?

Underground stems, also known as rhizomes or stolons, are modified plant stems that grow horizontally beneath the soil surface. Unlike roots, they possess nodes (joints) and internodes (the spaces between joints), just like above-ground stems. They also feature buds, which are capable of developing into new shoots and roots, allowing the plant to propagate vegetatively. This means that a single plant can rapidly create a colony of interconnected plants, making them notoriously difficult to eradicate.

Rhizomes vs. Stolons: Key Differences

While both are types of underground stems, there’s a subtle difference:

• Rhizomes: These are typically thick and fleshy, often growing just below or on the surface of the soil. They tend to grow horizontally and are responsible for spreading the plant outwards. Examples include bamboo, quackgrass, and ginger.
• Stolons (Runners): These are slender and grow along the surface of the soil or just underneath it. They produce roots and shoots at the nodes, creating new plantlets. Examples include strawberries and creeping buttercup.

Identifying Plants with Underground Stems

Key Identification Features

Careful observation is crucial. Look for these tell-tale signs:

• Horizontal Growth: Plants spreading rapidly in a linear or expanding fashion.
• Dense Patches: Clumps of plants connected underground.
• New Shoots: Emerging from the ground at intervals, not directly from the "mother" plant’s base.
• Stem-like Structures Underground: Carefully excavate around the plant to reveal the horizontal stems. Look for nodes, buds, and root emergence points.

Common Offenders: Plants with Underground Stems

Plant Name	Growth Habit	Problem Areas	Identification Tips
Quackgrass	Rhizomatous	Lawns, gardens, fields	Aggressive, blue-green leaves, creeping rhizomes.
Canada Thistle	Rhizomatous	Fields, pastures, roadsides	Prickly leaves, purple flowers, extensive root system.
Bamboo	Rhizomatous	Gardens, landscapes	Varying sizes and colors, aggressive spread.
Creeping Buttercup	Stoloniferous	Lawns, gardens, moist areas	Shiny leaves, yellow flowers, trailing stems.
Japanese Knotweed	Rhizomatous	Roadsides, waterways, gardens	Tall, bamboo-like stems, white flowers, persistent rhizomes.
Bermuda Grass	Both Rhizomatous & Stoloniferous	Lawns, gardens, golf courses	Fine-textured, aggressive spread, difficult to control.

Effective Control Strategies

Controlling plants with underground stems requires a multi-faceted approach and persistence.

Manual Removal

This is often the best option for small infestations, but it’s labor-intensive.

1. Dig Deep: Excavate around the plant, ensuring you remove all fragments of the underground stem.
2. Sift the Soil: Carefully sift through the soil to remove any remaining rhizome or stolon pieces. Even small segments can regrow.
3. Dispose Properly: Do not compost these stems, as they can survive and spread. Dispose of them in a sealed bag in the trash or burn them (where permitted).

Cultural Practices

• Healthy Soil: Promote healthy soil conditions to encourage the growth of desirable plants, which can outcompete the unwanted species.
• Mulching: Thick layers of mulch can suppress new shoot emergence.
• Solarization: Cover the infested area with clear plastic for several weeks during the hottest part of the year to bake and kill the stems underground. This works best in sunny locations.

Chemical Control (Herbicides)

• Systemic Herbicides: These herbicides are absorbed by the plant and translocated to the roots and underground stems, providing more effective control.
• Glyphosate: A non-selective herbicide that can be effective, but will kill any plant it contacts. Use with caution and protect desirable plants.
• Timing is Key: Apply herbicides when the plant is actively growing, usually in the spring or fall.
• Follow Instructions: Always read and follow the herbicide label instructions carefully.
• Multiple Applications: It may take several applications to fully control the infestation.

Creating Barriers

• Root Barriers: Install physical barriers around areas you want to protect. These barriers should be buried deep enough to prevent the rhizomes from growing underneath (at least 18-24 inches).
• Edging: Use edging around garden beds to prevent the spread of stolons into lawns.

Alright, that’s the lowdown on getting those underground stems under control! Hopefully, you feel ready to tackle them. Go get ’em!