Growing grass in flower beds can be frustrating. Over time, grass can invade flower beds, robbing precious nutrients and moisture from flowers. Eliminating grass from flower beds takes some work, but a few techniques can help restore flower beds to their former grass-free glory.

Why Grass Grows in Flower Beds

There are a few reasons why grass creeps into flower beds:

Spreading rhizomes and stolons – Many lawn grasses spread through underground stems called rhizomes or above-ground stems called stolons. As these spreading stems grow, they can make their way under and through flower beds.

Windblown seeds – Grass produces many seeds that can be blown or washed into flower beds, germinating to produce new grass plants.

Encroaching lawn edges – The edges of lawns often gradually advance into planting beds through growth of rhizomes and stolons. This causes the lawn to slowly conquer flower beds.

Disturbed soil – Soil disturbance from digging in flower beds creates ideal conditions for grass seeds to germinate and get established.

Dangers of Grass Growth in Flower Beds

Allowing grass to grow in flower beds can cause several issues:

Competition – Grass competes with flowers for water, nutrients, sunlight, and space. This competition stresses flowers and reduces their health and vigor.
Rapid growth – Grass grows rapidly and can quickly overwhelm slower-growing flowers. Areas of grass growth expand over time.
Visibility – Grass detracts from the visual appeal and design of flower beds. Emerging grass makes beds look unkempt.
Spreading weeds – Grass allows other weeds like dandelions to gain a foothold and infest flower beds.
Harboring pests – Long grass blades provide cover for slugs, snails, and other pests that can damage flowers.
Difficult maintenance – Grass mixed in with flowers makes maintenance like watering, fertilizing, and mulching harder.

Techniques for Removing Grass from Flower Beds

Killing grass in flower beds takes some persistence. Here are effective methods:

Solarization

Solarization uses the sun’s heat to kill grass and weeds in flower beds. Follow these solarization steps:

Mow surrounding grass very short.
Water the flower bed thoroughly.
Cover the bed tightly with clear plastic sheeting, securing the edges with bricks or soil.
Leave the plastic in place for at least 6-8 weeks over summer.
The heat under the plastic kills grass, weeds, and weed seeds.

Herbicides

Applying postemergence non-selective herbicides like glyphosate (Roundup) can control grass growing in flower beds:

Carefully spray grass leaves, avoiding flower contact.
Apply on a calm day to prevent drift onto flowers.
Repeat applications may be needed as more grass emerges.
Take proper safety precautions when using herbicides.

Boiling Water

Pouring boiling water directly on unwanted grass patches kills grass by scalding it:

Boil a large pot of water.
Carefully pour the boiling water directly onto grass growth.
Boiling water kills grass quickly without chemicals.
Repeat boiling water applications as new grass sprouts up.

Hand Digging

For small invasions, carefully digging up grass by hand eliminates it from flower beds:

Use a trowel, shovel, or soil knife to dig under grass clumps.
Try to remove all roots and rhizomes when digging.
Backfill holes with fresh compost to discourage re-growth.
Hand dig throughout the season to catch new sprouts.

Maintaining Grass-Free Flower Beds

Once grass has been removed from flower beds, continue proper maintenance to prevent re-infestation:

Apply mulch like wood chips or bark around flowers to block light from reaching grass. Refresh mulch regularly.
Edge and trim surrounding lawn edges often to contain grass spread. Consider installing physical lawn edging.
Pull young grass sprouts as soon as they appear before they establish. Be vigilant about hand weeding.
Avoid excessive soil digging that brings up buried weed seeds. Dig only when necessary.
Re-seed bare spots in lawns adjacent to beds to prevent grass from invading.
Solarize beds periodically to kill newly blown-in grass and weed seeds.

Alternative Groundcovers for Flower Beds

Rather than battling reoccurring grass, consider planting spreading groundcovers among flowers that outcompete grass naturally:

Creeping Thyme

Forms dense, matted layers that block light from reaching grass.
Tolerates foot traffic and releases a pleasant aroma when stepped on.
Requires minimal watering once established.

Creeping Sedum

Low-growing succulent groundcover that suppresses weeds.
Drought-resistant and requires little maintenance.
Varieties feature colorful flowers that attract pollinators.

Sweet Woodruff

Fast-spreading groundcover for shade that inhibits weed growth.
Fragrant leaves and pretty white spring flowers.
Goes dormant in summer, leaving space for other plants.

Vinca Minor

Aggressive spreader that quickly forms a weed-blocking mat.
Tolerates full sun or deep shade.
Features shiny green leaves and blue blooms in spring.

Ajuga

Rapidly growing groundcover that chokes out weeds.
Available in purple, blue, and variegated leaf varieties.
Produces dense vertical flower spikes in spring.

Using Mulch to Stop Grass Growth

Applying mulch in flower beds provides a simple, non-toxic way to prevent most grass and weed seeds from germinating. Different mulching options include:

Wood Chips

Made from chipped up branches and logs.
Available for bulk delivery or pickup in bags.
Must be re-applied every 1-2 years as chips decompose.

Shredded Bark

Made from shredded bark and wood.
Looks neat and provides a finished look.
Retains its form and color better than plain wood chips.

Compost

Nutrient-rich organic material adds nutrients as it breaks down.
Weed seeds can sometimes be present in compost.
May need to be topped off through the season.

Stone

Inorganic options like pea gravel, crushed granite, or river rocks.
Suppresses weeds and retains heat. Can be expensive.
Makes flower bed edges look clean and defined.

Fabric

Geotextile landscape fabric creates an impenetrable weed barrier.
Must be topped with mulch or small stones to hold in place.
Makes it harder for plants to seed into beds.

No matter the material used, apply mulch 2-4 inches deep for best grass and weed prevention. Leaving mulch too thin or bare spots can allow grasses to poke through. Refresh mulch layers annually, or whenever thinning is noticed.

Using Vinegar to Kill Grass in Beds

Household vinegar offers a non-toxic weed killing option for flower beds when applied full strength to grass leaves:

How It Works

The acetic acid in vinegar damages cell membranes, causing grass leaves to dry out.

Effectiveness

Works best on young, tender grass. May take multiple applications to kill established grass.

How to Apply

Use horticultural vinegar with at least 20% acetic acid content. Or concentrate household vinegar.
Spray vinegar directly on unwanted grass. Avoid getting vinegar on flowers.
Best results are seen when applied to grass blades heated by the sun.
Repeat applications to new growth until grass is dead. May take a few weeks.

Considerations

Works best on a sunny, warm day. Less effective in shade or when temperatures are cool.
Will kill any foliage it directly contacts. Must be applied selectively.
Rainfast once grass blades are completely wetted.
Irritates skin and eyes. Wear gloves and eye protection when applying.

Advantages

Fast and selective control when carefully applied.
Provides control of grass close to desirable plants.
Allows planting in spot treated areas after grass dies back.
More affordable and readily available than commercial herbicides.

So when needing spot treatment of isolated grass plants in a flower bed, vinegar can be an effective option.

Smothering Grass with Newspaper or Cardboard

Blanketing grass with layers of newspaper or cardboard is an eco-friendly way to smother out grass from flower beds.

How It Works

Blocks sunlight needed for grass growth.
Cut off air and causes grass to rot.
Sheet materials break down over time, adding organic matter to soil.

Application Tips

Wet newspaper sheets before applying to prevent blowing away.
Overlap sheets by 6+ inches so no grass pokes through.
Top with mulch or compost to hold in place and prevent photo-degradation.
May take 4-6 weeks of coverage to fully kill grass.

Suitable Situations

Areas being converted fully into planting beds:
Edges of beds being expanded.
-stale paths being eliminated.

Avoid Around

Desired grass you want to keep. Can kill lawns if sheets shift.
Annual flowers. May smother before grass dies.
Delicate perennials. Extended darkness stresses some plants.

With patience, smothering gives effective grass control when converting lawn edges or entire areas into planting beds.

Tilling to Uproot Grassy Weeds

Shallow tilling uproots grass plants from soil, providing temporary control in flower beds:

Where It Works

Annual flower beds being replanted each year.
Perennial beds with established plants. Go slow around crowns.

Tilling Tips

Set tiller blades to only penetrate 1-3 inches deep.
Till up and down the bed to rip grass roots from soil.
Remove uprooted grass clumps immediately.

Regrowth Prevention

Apply mulch after tilling to impede new growth.
Hand weed regularly to catch clumps that re-root.

Drawbacks

Can damage surface roots of plants if not careful.
Makes soil prone to compaction if over-tilled.
Must be repeated each season as buried seeds germinate.

Tilling gives a fast temporary fix but must be paired with other methods for long term control.

Using Corn Gluten Meal

Applying corn gluten meal in flower beds provides an organic pre-emergent weed control:

How It Works

Dried corn protein inhibits root development when it breaks down.
Prevents germinating seeds like grass from establishing.

Application Tips

Apply in spring before grass seeds sprout.
Reapply every 2-3 months during the growing season.
Use a spreader and apply at a rate of 20 lbs per 1000 sq ft.
Thoroughly water meal into soil after applying.

Limitations

Only affects seedling grass. Will not kill established grass.
Avoid areas where you are direct sowing seeds.
Takes 1-2 seasons to deplete the seed bank in soil.

Used properly, corn gluten offers safe, natural prevention of new grass invasions in beds.

Maintaining Lawn Edges

Keeping lawn edges back from flower beds provides a grass-free buffer that prevents encroachment:

Edge Frequently

Use a square shovel or lawn edger to cut clean edges.
Re-define edges every 2-4 weeks during peak growth.

Apply Barriers

Line bed edges with metal, plastic, or stone landscape edging.
Chemical edging products cauterize grass roots.

Grow Competitive Plants

Edging plants like thyme or sedum spread into lawns, dominating the boundary.

Remove Grass Clumps

Hand pull or spot treat grass escaping into bed edges.

Keeping lawn edges controlled is the first line of defense when battling grass invasion into flower beds.

Frequently Asked Questions About Killing Grass in Flower Beds

What is the quickest way to get rid of grass in my flower beds?

Using a non-selective herbicide containing glyphosate is the fastest way to kill existing grass in flower beds. However, chemical control may not be desired. Boiling water or high strength vinegar can provide rapid control in small areas when applied directly to grass leaves.

What should I put in my flower bed after removing grass?

After eliminating unwanted grass, put down a 2-4 inch layer of mulch like wood chips or compost to prevent regrowth. Alternatively, plant competitive groundcovers like thyme or sedum which will outcompete new grass sprouts. Adding annuals or perennials that tolerate plantings helps crowd out grass.

What home remedy kills grass permanently?

No home remedies provide permanent grass control by themselves. For long term suppression, a combination of techniques must be integrated, such as digging out grass roots, applying mulch layers, establishing competitive thick groundcovers, and maintaining clean lawn edges around beds. Preventing light from reaching grass seeds provides the best permanent control.

What month is best to kill grass in flower beds?

The ideal time is spring through mid-summer when grass is most actively growing and before it sets seed. Actively growing grass absorbs and translocates herbicides best. Young grass is also more susceptible to hand digging, smothering, or desiccation from boiling water and vinegar applications. Avoid treating dormant grass in winter.

Will wood chips kill grass and weeds?

Plain wood chip mulch alone will suppress about 80% of weed and grass growth but is less effective than landscape fabric. Grass can still sometimes poke through thin layers. Combining chips with compacted newspaper sheets provides a better grass barrier. Replenishing chips prevents light from reaching dormant seeds.

Does salt kill grass permanently?

Salt can give temporary control of grass in flower beds but generally does not permanently kill grass roots and rhizomes. Salt also degrades and contaminates soil over time. Avoid large amounts of salt and opt for other grass killing solutions that allow safe planting afterwards. Spot treat saline only as needed.

Summary of Removing Grasses from Flower Beds

Eliminating undesirable grass from flower beds provides a constant maintenance challenge. Success requires integrating multiple techniques based on the situation:

Start by cutting off light penetration with mulch layers, landscape fabric, or smothering. Darkness prevents seeds from sprouting.
Kill existing grass clumps with non-selective herbicides or by boiling water, concentrated vinegar, or manual digging.
Maintain sharp lawn edges next to beds with frequent edging and trimming to contain spread.
Replant treated areas with competitive groundcovers or annuals that crowd out grass.
Use pre-emergent corn gluten meal to inhibit newly germinating seeds.
Reduce soil disturbance that unearths buried weed seeds. Gently hand weed instead of tilling.
Solarize beds under clear plastic in summer to pasteurize soil and kill grass and weed seeds.

With diligence and persistence, flower beds can be reclaimed and kept lush and grass free using organic and chemical control techniques suited to each situation. Consult local garden centers to find specific products available in your region that can help win the battle against stubborn invading grasses.

How to Kill Grass in Flower Beds [FAQ]

Here are answers to frequently asked questions about eliminating grass growth in flower beds:

What causes grass to grow in my flower beds?

Grass often appears in flower beds when spreading rhizomes and stolons invade from the lawn edges. Grass seeds also blow or wash into beds, germinating to form new grass plants. Excessive soil disturbance from digging can bring buried grass seeds to the surface.

What’s the quickest way to get rid of grass?

Using a non-selective herbicide containing glyphosate applied directly to grass leaves provides the fastest control. Boiling water and high strength horticultural vinegar can also quickly kill grass when applied directly to foliage.

What should I plant after removing grass from beds?

Apply 2-4 inches of mulch after removing grass to inhibit regrowth. Also plant competitive groundcovers like thyme, sedum, or vinca minor which will outcompete any leftover grass. Annuals and perennials help crowd out grass.

How do I permanently kill grass naturally?

No natural, organic methods permanently kill grass seeds already in the soil. Integrating mulch layers, hand weeding, edging around beds, and replacing grass with alternative ground covers provides the best long term natural control.

When is the best time to eliminate grass from beds?

Control grass in flower beds during the active growing season of spring through mid summer. Actively growing grass absorbs systemic herbicides most effectively. Young, tender grass is also more susceptible to non-chemical control methods.

Should I put wood chips or mulch over grass?

Plain wood chip mulch provides moderate grass suppression but some can still poke through over time. Combining thick layers of chips with overlapped sheet mulching of cardboard or newspaper boosts effectiveness. Replenish mulch before it thins.

Will salt kill grass permanently?

Saline applied to grass can burn and desiccate leaves but generally does not permanently kill roots. Salt also degrades soil quality with repeated use. Minimize salt applications and integrate additional control methods that allow safe planting afterwards.

How do I stop grass from returning to flower beds?

Preventing light from reaching soil surfaces provides the best control of grass seeds. Maintain 2-4 inches of refreshed mulch. Plant thick groundcovers and avoid excessive soil digging that brings up buried seeds. Keep lawn edges back from beds with regular edging.

How to Kill Grass in Flower Beds [Conclusion]