Tree Coffee is having a climate moment

In the traditional growing belts of Kodagu, Chikkamagaluru and Hassan, growers talk about no longer following a memorized calendar. Jacob Mammen, managing director of Badra Estates, said climate change was already having a significant impact on the cultivation of traditional coffee varieties such as Arabica and Robusta. He explained that the biggest challenge comes from increasingly unpredictable weather patterns, particularly the timing and intensity of rainfall.The flowering of coffee plants depends on very specific rainfall patterns. A rainfall triggers flowering, and a “backup shower” about two weeks later helps the flowers bloom properly. However, in recent years, growers have been faced with an unstable situation – either too much rain, too little rain, or it doesn’t come at the right time. This disrupts the flowering cycle and directly affects yields. Extreme weather events are also becoming more frequent. Jacob noted that last year’s hail destroyed coffee flowers on the estate, causing crop failure in the affected areas. Unseasonal rainfall can also cause harvest and quality problems. “Early showers, sometimes as early as January, can cause new flowers to bloom while ripe cherries are still on the plants. When this happens, pickers must stop picking to avoid damaging the flowers. At the same time, rain can cause ripe cherries to spoil or dry out, affecting the quality of the coffee beans.”in a warming worldAgainst this backdrop, Jacobs said, there is growing interest in climate-adapted varieties such as Liberica coffee. Liberia has traditionally been considered a fence crop rather than grown as a primary plantation species. In Badra it is still mainly grown along borders as “tree coffee” rather than replacing Arabica or Robusta in the fields. However, the estate is beginning to reconsider this approach.Liberian coffee is considered more climate resilient than other major coffee varieties such as Arabica due to a variety of natural characteristics. Liberica trees can tolerate higher temperatures and grow well in hot, humid tropical environments, where Arabica coffee often does not grow well. These plants develop deep and extensive root systems that allow them to obtain water from deeper layers of soil, helping them survive drought conditions. They also show greater resistance to diseases such as coffee leaf rust, which has historically devastated many coffee plantations. Additionally, Liberica trees are larger and sturdier, able to withstand heavy rainfall, storms, and changing weather patterns. Their ability to grow in poor soil and adapt to changing environmental conditions makes Liberica a promising climate-resilient coffee variety as global warming increasingly threatens traditional coffee cultivation.Market demand is another factor driving renewed interest in Liberia. Jacob said buyers in India and abroad are increasingly curious about the variety because it has a unique fruity and sweet taste that sets it apart from Arabica and Robusta. However, Liberia still faces output-related challenges. Currently, its production is significantly lower than Arabica or Robusta. This is partly because it is still grown primarily as a tree crop alongside fences rather than as a fully managed plantation species. SeekingExcelsaAnother tree coffee variety, Excelsa, is also widely considered to be climate resilient. Since it shares many of the cold-hardy characteristics of Liberian coffee, the jury is still out on whether it is a Liberian coffee variety. Excelsa is more tolerant of high temperatures, irregular rainfall and humid tropical conditions than Arabica coffee, which is more sensitive to climate change. Adhi Savla, senior manager of coffee community at Blue Tokai, said they source Excelsa from South Indian Coffee Company but it is currently sold out. “The quantities are very small because they are experimental batches,” he said. “Excelsa is heavier-bodied with a distinctive cola flavor often reminiscent of cola, blackcurrants and molasses, making it a unique experience for coffee drinkers.”South India Coffee Corporation (SICC) has been exporting Excelsa since 2017. “We have been working with Kew Gardens UK since 2021 and they have proven that Excelsa and Liberica are two different varieties,” said Akshay Dashrath, co-founder of SICC and a fifth-generation coffee farmer. “In India, when it’s hot, it’s usually very dry. Sometimes our problem isn’t just the heat; it’s also too much moisture. For example, in 2024, we had 65 inches of rain on our farm. That’s historically normal, but what’s unusual is that 33 of those inches came in one month in July. These conditions are intolerable for Arabica and Robusta. Excelsa performs well in these variable conditions because it is a tree with deep roots.“Their Mooleh Manay Estate in Coorg produces about three tonnes of clean Excelsa every year. SICC has started cultivating Excelsa. “Arabica coffee has a 500-year history of breeding; Robusta coffee has a 150-year history of breeding. Excelsa and Liberica scored zero. What we have in India are basically wild populations that were introduced in batches in 1872, 1920s and 1940s,” Akshay added.Some people choose to be practicalFor Arvind Rao, former president of the Karnataka Growers Association, adaptation is now less about breakthrough genetics and more about practical mitigation measures. “Most of us haven’t really tried climate-adapted varieties because not even the Coffee Board has any real varieties so far,” he said. “So we’re managing whatever plants are already in our fields.” The current response is infrastructure and ecology. “We are conserving water, building water storage tanks, irrigating so that during the flowering period we can irrigate and mitigate drought to some extent,” Rao explained. The sunshade adjustment has also changed. “We maintain slightly higher shade to keep temperatures cooler. Of course, this reduces crop yields to some extent, but helps control heat stress.” Soil health has become central to the discussion. Compost and organic matter incorporation are used to improve water retention.Resilience alone is not enoughFrom a quality and market perspective, another industry observer and processing expert who works with post-harvest coffee processing and fermentation, Binny Varghese, who has traveled extensively to different coffee-producing regions in the country, believes that resilience is layered, not absolute.“From what I’ve seen in Karnataka and Tamil Nadu, S795 is still going strong,” Binny said. (S795 is an Arabica variety derived from the Kent and S288 lines, which contains some Liberica blood). It is known for its high yield, resistance to rust in the coffee leaves, and flavor with hints of mocha or chocolate. “It’s not trendy, but it’s genetically stable and relatively adapted to mid-altitudes. Through strict picking and controlled fermentation, it can produce very clean coffee with good acidity structure and good sweetness.“Binny added that selection No. 9 remains important. Selection 9 was developed in India by crossing Tafarikela, an Ethiopian Arabica coffee, with Hibrido-de-Timor, a rust-resistant hybrid. “Genetics determine yield potential and disease resistance,” he explains. “Processing determines the extent to which this potential translates into cup quality.”Tracking climate risks with dataConversations around climate risks have become noticeably more direct, he said. “Before, climate conversations were cautious. Now, they are data-driven and experience-based. Younger producers are using models.” Farmers now openly track irregular flower showers, temperature spikes during fruit development, and unexpected rainfall during dry periods—all of which can affect coffee bean density and the predictability of fermentation. “Interestingly, adaptation is no longer seen as just ‘growing new varieties,'” Binney noted. “It’s a combination of thinking — canopy management, spacing, moisture management, selective picking, even adjusting processing to handle inconsistent ripeness.”