Is Eucalyptus Bad for Soil? A Detailed Look at the Pros and Cons
Eucalyptus is a genus of trees that are native to Australia. The leaves and oil from these trees are often used in medicine, cosmetics and for other purposes. However many gardeners wonder if using eucalyptus is bad for soil. In this article, we’ll take a detailed look at the pros and cons of using eucalyptus around your garden.
Pros of Using Eucalyptus
There are some benefits to using eucalyptus in your garden when applied properly
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Acts as a natural pest repellent. The strong scent of eucalyptus can deter pests like insects rodents and deer from nibbling on plants. This allows gardeners to avoid using chemical pesticides.
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Suppresses weed growth. The oils released as eucalyptus leaves and bark break down can inhibit the germination of weed seeds. Less weeding means less work for you!
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Retains moisture. A thick layer of eucalyptus mulch can act as a barrier to retain moisture in the soil. This helps reduce water usage, especially in hot climates.
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Provides nutrients. As eucalyptus leaves and bark slowly decompose, they release beneficial nutrients like nitrogen and potassium into the soil. This nourishes plants and improves soil health over time.
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Has a natural appearance. Shredded eucalyptus bark has an attractive, earthy color that enhances the aesthetic of garden beds.
Cons of Using Eucalyptus
However, there are also some potential downsides to be aware of:
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Allelopathic properties. Eucalyptus contains oils and compounds that may inhibit the growth of sensitive plants like herbs, vegetables, and young seedlings.
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Repels beneficial insects. While deterring pests, eucalyptus may also repel pollinators and insects that benefit your garden.
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Environmental impact. Large eucalyptus plantations can negatively impact local water tables, native species, and biodiversity. Consider sourcing sustainable products.
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Toxic to pets. Eucalyptus oil and leaves can be toxic to cats, dogs, and livestock if ingested. Take precautions to keep pets away from eucalyptus mulch.
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Decomposes slowly. Whole, dried leaves take very long to break down compared to other mulches. Smaller particles are better.
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drainage issues. Too thick of an application can retain excess moisture and cause problems, especially for plants that require good drainage.
Best Practices for Using Eucalyptus
To reap the benefits while avoiding the potential drawbacks of using eucalyptus around your garden, follow these best practices:
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Use sparingly around sensitive plants. Avoid prolonged direct contact with seedlings, herbs, vegetables, and other susceptible plants.
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Apply a thin layer and maintain distance from plant crowns. A 1-2 inch layer is sufficient, and don’t let mulch touch the base of plants.
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Mix with other mulches. Combine with pine straw or leaves to moderate the allelopathic effects.
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Replenish annually. To prevent excessive decomposition and nutrient blockage, refresh eucalyptus mulch yearly.
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Monitor pets after application. Check that dogs and cats do not ingest the mulch and isolate treated areas if necessary.
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Water treated areas well. Help wash some oils into the soil and dilute chemical concentrations.
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Buy from sustainable sources. Support ethical eucalyptus production to lessen ecosystem impacts.
The Bottom Line
When used judiciously around the right plants, eucalyptus mulch can be an attractive, low-maintenance solution for your garden. But take care to minimize potentially negative impacts, especially on young and sensitive plants. Check for signs of reduced growth and adjust applications of eucalyptus accordingly. With some added precautions, you can safely enjoy the benefits of eucalyptus without sacrificing your garden’s health.
Rice seedling growth assay
In a seedling growth assay, rice (Oryza sativa) was used to demonstrate the growth-promoting potential of biosustained Trichoderma strains in greenhouse conditions (Abuhena et al., 2022b; Xue et al., 2021). After washing with autoclaved water (1–2 times), the seeds were disinfected by dipping in 75% ethanol (1 min), followed by dipping in 0.5% sodium hypochlorite (5 min), and finally washing 5 times with autoclaved water. After 1 h of autoclaving at 121°C and 15 pressure, the soil was collected (Abuhena et al., 2022d). Soil was mixed with 0.5 g of degraded leaf-mixed Trichoderma spore and kept overnight. There was 250 g of dried soil in each plastic cup. In each cup, three seeds were sown after 48 h of soaking with Serendipita indica (SI) inoculum. There were 11 treatments: T1–T9 for Trichoderma spores and SI application (for nine isolates) and T10 for non-treated seedlings (control). T11 (sole SI) was also used as control for checking SI infection rate in rice root. For each treatment, five replications were used in this experiment. For up to 30 days, all plants were grown in a greenhouse at 28 ± 2°C and 75 ± 5% relative humidity. Additional plants were discarded from the cups at 5 DAG (Days after germination) while keeping one plant in each cup. After 30 DAG, seedlings were harvested from each treatment for data collection.
Assessment of Serendipita indica colonization
The root sample was taken and rinsed with demineralized water after 65 days of rice seedling planting. The root segments (1 cm long) were softened in 10% potassium hydroxide at 90°C for 15 min to facilitate de-colorization. To determine the fraction of root length colonized by Serendipita indica, the sample was neutralized for 5 min at room temperature with a 2% HCl solution and stained for 2 min at 90°C with a 2% trypan blue-lactoglycerol solution dye. The root colonization percentage was calculated using the magnified intersection method (Maitra et al., 2021).
XLSTAT (2021) was utilized to carry out the PCA (XLSTAT, 2021). Using R program (R Development Core Team, 2021), One-way ANOVA was conducted to test the influence of Trichoderma spores with SI on grain yield and water productivity under different cultivation conditions. A pairwise comparison by t-test was conducted to test the effect of Trichoderma spores on pH change before and after inoculation. Tukey’s honestly significant difference (HSD) test was used to examine the significant difference of different Trichoderma isolates on bioactivity, Serendipita indica colonization in rice seedling roots, and seedling growth parameters of rice if the data satisfied the normality of distribution and homogeneity of variance after log or square root transformation. For the data that did not satisfy the normality of distribution and homogeneity of variance after transformation, a nonparametric Conover’stest using the ‘post hoc.kruskal.conover.test’ function in the PMCMR package (R Development Core Team, 2021).
The controversial tree- Eucalyptus | Ep. 2 | Beyond Garden
FAQ
Are eucalyptus leaves toxic to soil?
Yes, of course!! Growing eucalyptus decreases the soil fertility. It degrades soils and release carbon. That too, planting eucalyptus as monoculture tree plantations are very harmful to soil. It decreases the soil pH and increases soil acidity such that Aluminium ions play a dominant role.
How does eucalyptus affect the soil?
Eucalyptus trees absorb significant amounts of water and nutrients from soil which can impact on water and nutrients availability by contending with agricultural crops and other foliage for water and nutrients.
Is eucalyptus bad for other plants?
Eucalyptus trees can inhibit the growth of other plants around them due to several factors: Allelopathy: Eucalyptus trees release chemicals from their leaves, bark, and roots into the soil, which can be toxic or inhibitory to the germination and growth of nearby plants.
What are the disadvantages of eucalyptus?
One of Eucalyptus’ main drawbacks is an extremely high rate of transpiration that causes detrimental effects on the environment. Compared to other trees in the country, Eucalyptus contributes much more to draught through transpiration 18–20 times higher.