Coffee, climate change and the importance of shade
During a recent visit to Costa Rica I toured an organic coffee plantation and discovered a lot about the importance of shade which we can apply to our gardens as our climate warms up
I’m on a tour of a coffee plantation in Costa Rica but all is not well. The guide points to a bush that has green fruits and says that the fruits will not be able to be harvested and will drop to the floor. Why? The problem is that the rains have come four weeks early and have triggered flowering and now the fruits are forming, but its way too early. The plantation needs dry weather to harvest the crop, but if the plants flower early, the ripe red fruits will be ready in the rainy season when there are no pickers, so will drop to the floor to be eaten by animals and will be lost. In a good year, this 12 ha plantation harvests 4000 kg of fruits, but last year’s harvest was down 50% and now its happening all over again.
Worldwide, the coffee industry is suffering as climate changing is bringing unpredictable weather, as well as more disease and pests.
Traditionally, coffee is grown on slopes without shade. But the dry season temperatures are creeping up, making conditions difficult for both the plants and the pickers. Coffee grows in areas of high rainfall, so the higher altitude slopes of Costa Rica’s central region are perfect, but the rain here is getting more intense, and this leads to more soil erosion.
This is an organic plantation where coffee plants are grown under trees. It’s actually called shade coffee, but we know this system of growing as agroforestry. Being organic, the yields are much lower, but it may be a more future-proof, resilient method of growing coffee.
The benefits of shade
Shade is critical, especially in the dry season, as it reduces the temperatures for plants and workers and protects the soil. Here, the large trees cast a light shade over the coffee plants.
This was once a sun plantation, but when the American owners bought the plantation, they started planting trees – thousands of them – including banana and palm. which provide a secondary crop, and legumes to fix nitrogen. There are lots of flowering plants too, which attract a wealth of insects and more than 140 species of birds. The wasps, in particular, are important as they prey on the borer beetles.
Here, the leaves are allowed to fall to the ground to provide a mulch that helps to conserve water in the dry season and protect the soil from sun and extreme rainfall, as well as provide a habitat of wildlife.
A vulnerable crop
Coffee is notoriously prone to pests and disease, such as coffee borer beetle, and coffee leaf rust, so its not surprising that coffee plants are sprayed regularly to keep them healthy. Organic plantations are few and far between which makes this one quite unusual for Costa Rica. Not only are the yields from the unsprayed plants lower, but the life span of the plants is less too. Spraying can keep a plant healthier for longer, so the average life of a conventionally grown coffee plant is 50 years compared with 25 years for organic.
There are two main species of coffee – robusta (Coffea robusta) and arabica (Coffea arabica). The original African robusta grow faster and taller and yields much more. The beans are smaller and more pest resilient, probably because they contain more caffeine, but the flavour is not as good as its cousin, the arabica coffee. Today, the largest producer of robusta beans is Vietnam.
The arabica coffee plant is slower growing with lower yields. It’s more vulnerable to pests and disease, but the flavour is so much better. And I must say that the arabica coffee that we enjoyed while staying here was amongst the best I had ever tasted, even better than my favourite, Ethiopian Yirgacheffe arabica coffee.
Looking ahead, its not going to get any easier to grow coffee, especially organic coffee. The higher temperatures and erratic rainfall patterns mean that the plants are under more stress, which can make them more susceptible to pests and disease. The growers are going to have to be adaptable. Perhaps they will have to look to grow coffee in new areas, move higher up the mountain slopes for example, or grow different species of coffee, especially those which are known as climate-smart coffee plants
Fair trade
Organic farming is not just about avoiding pesticides and artificial fertilisers, its also about fair trade and this coffee plantation is an excellent example. Coffee growers are finding it increasingly difficult to get pickers and the younger generations of Costa Ricans are wealthier and don’t want to work in the fields, so coffee growers are dependent on migrant workers who come for several months. Their pay is usually dictated by the quantity of beans that they harvest, which means they work long hours in the sun. This plantation is different. Since the plantation has a much smaller harvest, the owner pays 10x the norm to ensure the workers come for the season.
And like all commodity crops, most of the profit is to be made by ‘adding value’ through processing. Most growers export unroasted beans to countries such as the US where the coffee roasters and supermarkets take most of the profit. There is a small artisan coffee mill on this plantation where the beans are roasted and used by the neighbouring hotel or sold to visiting tourists. This means the coffee grower sees more of the money and can afford to pay the regular workers and the pickers more.
It was good to learn that there is a growing number of artisan coffer millers who are adding value to their beans by applying techniques that create better flavoured coffee, such as fermentation and honey processed coffee, which have better flavour profiles. Their unique flavoured beans are helping to put some Amercian artisan coffee roasters on the ‘coffee map’. It’s all small scale, but it’s a start and helping tsmall producers to gain more of the profit.
Some tips from the grower
Everything about great tasting coffee is to do with looking after the beans. As soon as coffee beans are roasted. they start to lose flavour, so it’s best to freeze the beans. Pop enough for a few servings into a small air tight bag, rather than one large bag, so you avoid opening and closing a freezer bag to take out beans and let in moisture. Once the beans have been ground, use immediately. The flavour profile starts to change within just 15 minutes!
So what about shade?
I don’t think we think about shade enough. Traditionally our gardens are quite open with expanses of lawn and herbaceous beds. Our veg beds are open too.
But we need to think about the future. With the potential of higher summer temperatures and drought, we need to think about casting more shade to benefit our plants, wildlife and ourselves.
Think back to 2022. I don’t we were sitting out on our south facing patios when temperatures were soaring to 30+C – we are all seeking out shade. And as our weather becomes a bit more extreme, it will become increasingly difficult to establish trees and shrubs - they will need more irrigation and protection during their early years. So, I am looking at the shade in my garden, working out where I can introduce more.
And walking around Mediterranean gardens, its interesting to see that a number of the plants that we associate with growing in open, sunny aspects, are growing well in the shade. In our climate the intensity of the sun is less, so these plants thrive in full sun, but increase the temperatures and the intensity of the sun, and you find they cope quite well with, or even prefer, dappled shade.
So plenty to think about
Happy Gardening
Sally
Talks and Workshops
Talk 9 May Sally is speaking to the Weston Garden Club in Bath
Talk 11 May Sally is speaking at the FarmED Literary Festival - the venue is brilliant and the speakers awesome
Talk 30 May & 1 June Sally is giving a talk at the Bath and West Show, Shepton Mallet - times to be confirmed
Talk 15th June Kim is speaking at the BBC Gardeners World Live Show
Talk 4 July Sally is speaking at the RHS Hampton Court Festival, 4om on the How To stage
Talk 13 September Talk by Sally at Yeo Valley Gardens ,Organic September Celebrations, nr Bristol