How Do Fungal Spores Survive for Years in Soil?

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Fungal spores can persist in soil long after the fungus that made them has died. People who ask how do fungal spores survive for years in soil usually want the mechanism: what kind of spore lasts, what makes it wait, and how a population keeps a reserve in the ground. The sources used here describe dormancy, resting spores, germination spread across months, and resting structures in soil fungi. They do not give a measured number of years for any species, so this article keeps to what they state and marks the gaps. The explanation draws on two research papers, one on stress-driven sporulation and one on resting spores in insect-pathogenic fungi.

Quick answer

• Most species produce two main types of spores: conidia and resting spores.
• Resting spores generally are dormant directly after production and need specific conditions to germinate.
• In the soil, resting spores germinate over several months, and not all of them germinate in any given year, so a reservoir persists.
• Resting structures give many soilborne and plant-associated fungi a way to persist over time.

Two kinds of spores

Most species produce two main types of spores, conidia and resting spores. Conidia are the spores that are generally able to germinate and infect hosts soon after they are made. Resting spores are a different kind of spore, designed for waiting.

The second paper explains the difference in more detail. While conidia are generally immediately able to germinate and infect hosts, azygospores or zygospores, which are commonly referred to as resting spores, are thought to enter dormancy after production. The result is that resting spores become environmentally persistent forms. This is the core reason they can remain in soil.

The first paper places spores within a wider set of fungal reproduction strategies. Asexual spores generally preserve the parental genotype and support dispersal or survival. In other words, spores serve two purposes: they carry the parent’s genetic makeup forward, and they help the fungus survive and spread.

Dormancy and the conditions for germination

Resting spores generally are dormant directly after production and require specific conditions for germination. Dormancy therefore means the spore waits until those conditions are met.

The second paper also describes resting spores inside insect hosts. Resting spores within cadavers of later instars enter dormancy when drying. Drying is therefore one of the conditions that moves a spore into the dormant state. The same paper notes that cadavers containing resting spores eventually decompose on the soil surface.

The sources treat dormancy and germination as two linked steps.

Where spores persist in the soil

The location of the spores matters as much as their dormancy. The second paper reports that most resting spores persist in the surface layers of the soil during summer and winter. This is the zone where the spores are held after the host decomposes. The same paper describes that persistence as occurring across both summer and winter, which means it is not limited to a single season.

The paper also describes how the cycle connects to the host population. In spring, when host eggs begin to hatch, resting spores begin germinating to cause primary infections. Those primary infections lead to cycles of secondary infections, which eventually result in production of resting spores that are dormant. So the soil reserve is refilled by the infections that the spores start.

Taken together, the soil acts as a holding area. Spores stay near the surface, wait through the seasons, and become active when the host and conditions line up. The second paper describes this as a reservoir of resting spores that persists in the soil.

Staggered germination keeps a reserve

The main reason a reserve lasts is that germination is spread out. Resting spores germinate over several months, and not all resting spores in the soil germinate every year. Because of that pattern, a reservoir of resting spores persists in the soil. Some spores germinate in one season, while others remain dormant for later seasons.

The paper also says reservoirs of resting spores can germinate for variable lengths of time, including up to several months. The length of the germination period varies.

This pattern links to infection. The second paper states that germination of resting spores can provide primary infections that initiate secondary cycling based on conidial infections. So the reserve does more than sit in the soil; it feeds new cycles of infection when conditions allow.

Resting structures in other soil fungi

Resting spores are one example of a broader strategy. The first paper notes that resting structures such as chlamydospores and sclerotia provide temporal persistence in many soilborne and plant-associated fungi. Temporal persistence means that these structures help the fungus last through unfavorable periods over time.

The first paper also describes asexual sporulation under stress as a way to survive or spread. Spores can survive or disperse better than vegetative cells, which is the active growing form.

How we chose

This article uses two research articles hosted on PubMed Central. The first, titled When growth becomes risky, covers stress-driven sporulation and sexual development in fungi. The second, titled Sleeping Beauties, reviews horizontal transmission via resting spores of species in the Entomophthoromycotina, a group of insect-pathogenic fungi. Both were opened on 2026-10-28 and both returned HTTP 200.

The first paper gives the general strategy of spores and resting structures. The second paper gives the detailed behavior of resting spores in soil, including dormancy, seasonal persistence and staggered germination. Each claim in this article is tied to a verbatim quote recorded in the research note for this article. Claims that could not be tied to a quote were removed.

This article does not give advice on products, prices or ratings, because the topic is a fungal biology question.

For related reading on how spores move, see how fungal spores travel on wind currents. For a comparison with dormancy in plant seeds, see how seeds decide to stay dormant.

What we could not verify

The second paper studies insect-pathogenic fungi. The sources do not show that the same persistence pattern applies to every soil fungus. This article does not present the insect-pathogen pattern as a general rule for all fungal spores in soil.

What the sources do not say

The sources do not give a measured survival period in years for any fungal species, so the question of how long a spore can survive in soil is not answered with a number here. They do not describe the spore wall chemistry that might allow longer survival. They also do not compare soil types, moisture levels or temperatures in a way that would let a reader predict survival in a specific garden.

Frequently asked questions

Do fungal spores really survive for years in soil?

The sources describe resting spores that persist in soil and germinate over several months, with not all of them germinating each year. They do not give a measured multi-year survival period for any species.

What is a resting spore?

A resting spore is a spore that is thought to enter dormancy after production and to become environmentally persistent, unlike conidia, which are generally able to germinate immediately.

Why do not all resting spores germinate in the same year?

The second paper reports that resting spores germinate over several months and not all of them germinate every year. This keeps a reservoir of resting spores in the soil.

What conditions do resting spores need to germinate?

Resting spores generally require specific conditions for germination, according to the second paper. The sources do not list the exact conditions for every species.

Do spores only survive by becoming resting spores?

No. The first paper says asexual spores support dispersal or survival, and that resting structures such as chlamydospores and sclerotia provide temporal persistence in many soilborne fungi. Resting spores are one strategy among several.

Sources

• When growth becomes risky: stress-driven sporulation and sexual development in fungi. PubMed Central. https://pmc.ncbi.nlm.nih.gov/articles/PMC13433876/ (opened 2026-10-28, HTTP 200)
• Sleeping Beauties: Horizontal Transmission via Resting Spores of Species in the Entomophthoromycotina. PubMed Central. https://pmc.ncbi.nlm.nih.gov/articles/PMC6165266/ (opened 2026-10-28, HTTP 200)