Your Guide to Weed Killer Types

Keeping weeds under control is essential for maintaining healthy lawns, borders, hard surfaces, and commercial landscapes. But with so many herbicide types on the market, it’s easy to feel overwhelmed. Terms like systemic, contact, residual, selective, and total often overlap, and a single product can fall into more than one category.

To help you make confident, effective choices, we’ve broken down the main weed‑killer types, how they work, and where each one performs best.

Best for: Fast knockdown of small annual weeds
Explore more: Contact weed killers

Contact herbicides work exactly as the name suggests – they kill only the parts of the plant they physically touch. They act quickly, often showing visible results within hours.

Because they don’t move into the root system, they’re ideal for young, shallow‑rooted weeds like chickweed, bittercress, cleavers, and groundsel. However, deep‑rooted perennials usually regrow and may need repeat treatments.

Typical uses:

• Treating small annual weeds in beds, borders, and hard surfaces
• Situations where you want fast results
• Targeted spot‑treatment around desirable plants

Common actives: Pelargonic acid, Carfentrazone‑ethyl

Products: New-way Weed Spray, Finalsan

Best for: Deep‑rooted, persistent weeds
Explore more: Systemic weed killers

Systemic herbicides move through the plant’s vascular system, reaching stems, leaves, and crucially, the roots. This makes them highly effective against tough perennials such as dandelion, dock, bindweed, bracken, and nettles.

Typical uses:

• Clearing perennial weeds from gravel, paving cracks, and hard surfaces
• Treating weeds in beds when using selective systemic formulas
• Situations where long‑term eradication is the goal

Common actives: Glyphosate, Cycloxydim

Product range: Glyphosate weed killers

Best for: Lawns and grassland where the grass must remain unharmed
Explore more: Selective weed killers

Selective herbicides target specific plant groups while leaving others untouched. Lawn‑safe weed killers, for example, are formulated to eliminate broadleaf weeds like clover, daisies, and buttercups without damaging turf.

They work by disrupting growth processes in susceptible plants, causing abnormal shoot and root development that eventually kills the weed.

Typical uses:

• Lawn care
• Pasture and grassland management
• Areas where you need to preserve grass while removing broadleaf weeds

Look after your lawn all year round with our summer, autumn and winter product pack guides.

Common actives: Fluroxypyr, Clopyralid, Dicamba

Product range: Selective weed control

Best for: Long‑term prevention on paths, driveways, and non‑planted areas
Explore more: Residual weed killers

Residual herbicides create a chemical barrier in the soil that prevents weed seeds from germinating. They can keep surfaces clear for months – often up to five – making them ideal for hard landscaping and ornamental areas where no replanting is planned.

Because they stop seeds from sprouting, they’re also known as pre‑emergent herbicides.

Typical uses:

• Paths, driveways, and gravel areas
• Ornamental tree and shrub plantings
• Combining with other herbicides for complete control

Common actives: Propyzamide, Isoxaben, Flazasulfuron, Napropamide

Products: Chikara, Hurricane, Lockstar, Flexidor

Best for: Clearing all vegetation from an area
Explore more: Total weed killers

Total weed killers eliminate any plant they touch. They can be either contact or systemic, but the key point is that they are non‑selective – perfect for complete clearance before landscaping or cultivation.

They should be applied carefully on still days to avoid spray drift onto desirable plants.

Typical uses:

• Preparing the ground for planting
• Clearing hard surfaces
• Removing all vegetation from unmanaged areas

Common actives: Glyphosate (systemic), Pelargonic acid (contact)

Product Range: Glyphosate weed killers, Non-glyphosate weed killers

More information on industrial-strength total weed killers that really get to the root of the problem.

Best for: Ponds, lakes, and waterside vegetation
Explore more: Aquatic weed killers

Aquatic‑approved herbicides are specially formulated for use in or near water. They must be applied with precision to avoid contamination, and in the UK, using them in open waters like rivers requires Environment Agency approval.

Typical uses:

• Controlling pond weeds
• Managing vegetation around lakes and water features

Common actives: Glyphosate, Biocar 405A (adjuvant)

Products: Glyphosate weed killers

Read our guide for advice and insights into the best glyphosate weed killers on the market.

Explore more: Pre‑emergent weed killers
Explore more: Post‑emergent weed killers

Pre‑emergent herbicides (a subset of residuals) prevent weed seeds from germinating. They’re best applied in spring before the main growing season.

Post‑emergent herbicides work only on weeds that have already sprouted and are in leaf.

With so many herbicide options available, it can be difficult to know which one is right for your specific situation. The table below provides a quick comparison to help you identify the best weed killer for your needs.