How to kill Oxalis weed without chemicals? - Weedtechnics

How to kill Oxalis weed without chemicals?

Jeremy Winer

This blog will cover all aspects of killing Oxalis weed using steam weeding.

Top 6 reasons Oxalis weed is notoriously difficult to manage and eradicate.

The oxalis weed is notoriously difficult to manage and eradicate for several reasons:

  1. It reproduces prolifically through seeds, bulbils (small bulbs), and underground rhizomes/tubers. Even small pieces of the plant left in the soil can regrow.
  2. The bulbils and tubers allow the plant to survive harsh conditions and regrow when conditions improve, making it very persistent.
  3. Oxalis has a long growing season from spring through fall, giving it ample time to spread and replenish its energy reserves.
  4. Hand-pulling is ineffective as it leaves behind the underground bulbils and tubers which will simply regrow. Digging out all the underground parts is extremely labor-intensive.
  5. There are no selective herbicides that will kill oxalis without also damaging desired plants in garden beds. Non-selective herbicides like glyphosate must be carefully applied to avoid harming other vegetation.
  6. Multiple herbicide applications are required over several years to deplete the seed bank and energy reserves in the soil to fully eradicate an oxalis infestation.

In summary, the oxalis weed’s prolific reproduction through seeds, bulbils, and rhizomes, combined with its long growing season and lack of selective herbicide options, make it an extremely tenacious and difficult weed to control and eliminate from gardens and lawns.

What are the most common signs of an oxalis weed infestation ?

The most common signs of an oxalis infestation include:

  1. Presence of the distinctive clover-like or heart-shaped leaves of oxalis plants growing in lawns, garden beds, or pots.
  2. Yellow flowers appearing, indicating the oxalis plants are mature and producing seeds to spread further.
  3. Visible bulbils (small bulbs) or underground rhizomes/tubers, which allow oxalis to persist even after the above-ground parts are removed.
  4. Rapid spread and dense patches of oxalis, as it reproduces quickly through seeds, bulbils, and rhizomes
  5. Difficulty in controlling or eradicating oxalis despite efforts like hand-pulling or herbicide application, due to its persistent underground storage organs.
  6. Stunted growth, wilting, or sudden leaf drop in desired plants growing near oxalis infestations, as oxalis can outcompete other plants for resources.
  7. White spots, stippling, or webbing on oxalis leaves, which could indicate insect infestations like spider mites, mealybugs, or whiteflies that are common on stressed oxalis plants.
  8. Presence of pests like fungus gnats, fruit flies, or other flying insects around oxalis plants, especially in moist soil conditions.

The key signs are the distinctive clover-like leaves, yellow flowers, rapid spread, and persistence despite control efforts due to the underground bulbils and rhizomes that allow oxalis to regrow repeatedly.

Harmful roundup herbicide costs

What are the environmental impacts of using herbicides on oxalis weed?

Using herbicides to control oxalis can have several negative environmental impacts:

  1. Non-target damage: Many herbicides used for oxalis control, like glyphosate and glufosinate, are non-selective and can kill or damage desired plants in the vicinity through spray drift, soil mobility, or root uptake.
  2. Bare ground: The use of non-selective herbicides often leaves bare ground for extended periods by killing all vegetation, disrupting the ecosystem and increasing erosion risks.
  3. Wildlife impacts: Herbicide use in natural areas can expose wildlife like birds and pollinators to toxic chemicals, reduce food sources like berries, and contaminate water sources. A UK study found gardens using pesticides had significantly fewer bird species.
  4. Persistence: Oxalis’ underground bulbs, tubers and rhizomes allow it to regrow after the above-ground parts are killed by herbicides, requiring repeated applications over multiple years to attempt eradication.
  5. Resistance: Repeated use of the same herbicide mode of action can lead to the development of herbicide-resistant oxalis biotypes, perpetuating the cycle of increased herbicide use.
  6. Soil and water contamination: Herbicides can leach into groundwater or runoff into surface waters, contaminating water sources and impacting aquatic life.

While selective herbicides may reduce some impacts, the lack of truly selective options for Oxalis weed killer often necessitates broad-spectrum herbicide use with associated environmental risks. Cultural and mechanical controls may be more sustainable long-term management approach.

Steam weeding Oxalis weed using our SatusteamTM technology is the best and most reliable option.

Weedtechnics’ SatusteamTM technology can effectively control and potentially eradicate oxalis weeds over time through repeated applications, but it does not provide permanent eradication from a single treatment. Here’s how it works:

Initial Oxalis weed kill:

The combination of saturated steam at 98-103°C (205-218°F) and boiling water instantly cooks and kills the above-ground parts of oxalis plants on contact. This initial treatment destroys the leaves, stems, and any exposed bulbils/tubers.

Depletion of oxalis weed energy reserves:

The underground bulbils, tubers, and rhizomes that allow oxalis to regrow are not completely eliminated in one pass. However, each SatusteamTM application forces the plant to regrow by depleting its energy reserves stored in these structures.

Repeated steam weeding treatments:

To achieve effective long-term control, SatusteamTM treatments need to be repeated every 4-6 week. This frequent re-treatment prevents oxalis from replenishing its energy reserves through photosynthesis and forces it to eventually exhaust its underground storage organs.

Oxalis weed seed bank depletion:

The high heat from SatusteamTM can denature oxalis seeds in the top layer of soil, preventing them from germinating.Over multiple treatment seasons, the persistent seed bank is gradually depleted.

Monitoring and spot treatments:

Even after multiple years of treatments, some oxalis may still regrow from deeply buried tubers or new seeds. Monitoring and spot SatusteamTM treatments are required to manage any new growth and prevent re-establishment.

While a single SatusteamTM application cannot permanently kill oxalis due to its persistent underground structures. The repeated high heat exposure and depletion of energy reserves can achieve effective long-term control and potential eradication over 2-3 years of diligent treatments according to Weedtechnics. Consistent monitoring and spot treatments may still be required for complete management.

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About the Author : Jeremy Winer

Jeremy Winer has 30 years of practical experience in implementing integrated holistic approach to organic weed management across urban landscapes, recreational parklands and wetlands. He currently runs Weedtechnics specialising in providing chemical reduction and non-toxic weed control programs to municipalities across Australia. He has developed, patented, manufactured, and commercialised the Steamwand method of creating saturated steam for vegetation control.