Salak Palm: A Guide for Tropical Permaculture
This article was originally published at the Porvenir Design blog.
Salak palm or snake fruit (Salacca edulis or Salacca zalacca) is a high value understory species for tropical agroforestry plantings. Salak palm is native to southeast Asia, where it is commercially cultivated in Indonesia, Malaysia, and Java, in their wet tropical lowland climates. At higher elevations the "Bali" variety can be grown. It produces a delicious fruit, eaten out of hand, with a taste similar to strawberry with an apple-like texture. The fruit transports well and can be stored at room temperature for a week with little degradation in quality.
This guide has been created based on the experience of growing a small number of plants, 30 palms, at Rancho Mastatal Sustainability Education Center in Costa Rica. It was created with the support of Peter Kring of Finca La Isla, a fruit farm in Puerto Viejo, Costa Rica, that has been growing and selling Salak fruit for over 20 years.
This short guide provides advice on propagation, planting and establishment, pruning and pollination management, and more.
Agroforestry Establishment
Propagation
Salak palms are individually male or female and you need to have both for fruit production. There is no way to know if a seedling salak will be male or female until it flowers, some 3-4 years after planting.
Salak palm is easily started from seed. Seeds should be placed sideways and half buried in a well drained potting mix.
Asexual propagation, usually to increase female plants, is done through sucker removal. Soil should be mounded up around the base of the sucker. This allows the sucker to form its own root system. Then use a saw to partially sever the connection to the mother plant. This process should be repeated every few weeks over a two month period, until the plants are separated and the sucker has it's own root system. The sucker can be removed and placed in the nursery for further establishment.
Establishment
Once plants in the nursery have reached at least 40 cm in height they are ready to go in the ground. They should be planted at the beginning of the rainy season. The soil around the palm should be heavily top-dressed with biochar, manure, compost, etc and then mulched. Salak feeder roots will come up into this mulch.
Salak can be supported by additional species such as Musa sp, Gliricida sepium (and other legumes), and Tithonia diversifolia. All of these fast growing plants provide shade for the young palms and can all be pruned/chopped aggressively for mulch.
Guilding
These palms are traditional understory species in their native forest habitat of SE Asia. The leaves reach 5 meters into the air, but they are not a dense plant if pruned properly.
They are best planted under a canopy of fruit, nut, or timber species which are low maintenance and let through about 50% of the sun's light. This is a similar setting to shade grown coffee and cacao.
The spikey nature of Salak discourages overstory species whose fruit falls to the ground upon harvest or must be maneuvered around easily for harvest.
Layout and Spacing
Salak are dioecious, meaning each individual plant either produces female flowers or male flowers, although there are some varieties of Salak which are known to be self fertile. In order to balance pollination and production it is recommended to have 3 female plants for every 1 male plant in an orchard.
Individual palms should be planted 2.5 meters apart.
This 3:1 ratio and 2.5 meter spacing can be achieved in a number of ways. One can plant at 5 meters apart, divide suckers from sexed females and plant these in-between at 2.5 meters. Or one can plant out at the final spacing and thin out males, replacing them with divided female suckers.
Salak are best planted in the same vicinity because of there pollination needs.
Management
Pruning
During years 1 to 3 the palm should be minimally pruned. Only remove outer leaves that are dying. You want to encourage as much photosynthesis as possible while the plant is approaching sexual maturity.
Once the plants reach full size, 3 plus meters tall, and begin flowering you should remove all outer leaves. Leave 4 to 5 leaves, as part of the original mother plant. Remove any leaves that interfere with walking paths.
Don't let suckers develop unless you need them for propagation.
If flowers emerge between an outer leaf and the palm trunk, remove the leaf in order to expose the flower for pollination.
Cut leaves should be chopped into smaller pieces and placed in a pile that doesn't interfere with access or management.
The best tools for this job include loppers, a sharp machete and a pruning saw with a long blade or handle.
Pollination
Salak plants are either female or male and are pollinated by a number of native pollinators, including stingless bees. But these pollinators are inefficient, with only 10 to 15 % of flowers producing fruit. By hand pollinating Salak, you can easily achieve close to 100% pollination.
Female flowers are coned shaped and covered with a dense fiber sheath. As they develop over many months slowly remove their outer sheath. This will allow you to completely see the flower as it approaches maturity. Once removed from these sheaths the cone takes one to four weeks to open. Once open the flower reveals a deep pink color which is ready to receive the male flower.
The male flower needs little management. When pollen is available the flower also opens up and reveals a pink interior, although in a much subtler way. Usually the pollen granules are easily visible though and stingless bees are often indicators of a ready flower.
The male should be removed with clipperss and brought to the female plant, where it is used to "dust" the open female flower. This is best done in dry weather, which allows the pollen to fall out of the male flower with ease. It is wise to check your salak grove for receptive female flowers ever other day.
Within a few days the flower will harden up if it was successfully pollinated. If not it will become soft and should be removed. All dead flowers, male and female, should be regularly removed to encourage more flowering.
Harvest
Plants will begin to flower at three to four years of age.
To determine if the fruit is ready to harvest, try one from a bunch and see if the seed color has turned from white to brown or light brown. See color is the best way to determine if a fruit is ready to pick. It is best to try fruit from the base of the bunch. If the individual fruits fall off of the bunch, they are likely ready.
Pests, such as aguti, can compete for ripe fruit.
The fruit does not ripen off of the plant.
Time Commitment
We budget one minute per plant, 2 to 3 days per week, in order to meet all of our pollination, flower management, and pruning requirements.
In addition to this, time should be set aside a few times per year to provide mulch, prune support species, and add amendments (limestone, foliar sprays, manure, compost, etc).
Overall salak is a crop that gives back when you give it the attention it needs. If you are consistent about pollination, regularly prune the spare leaves, and give a little fertility, then they will reward you with one of the best tropical fruits you will ever taste.
Need Help Siting Your Salak?
The team at Porvenir Design is ready to come to your site and put stakes in the ground. Write us at info@porvenirdesign.com for more information.
Around the Permaculture World
Core Team member Scott is teaching two workshops in Monteverde at the Valle Escondido Reserve and Monteverde Inn during the month of November. Consider joining him for a 2 day Introduction to Permaculture or a 2 day Introduction to Agroforestry course!
Ranch friends at ViVerde in Grenada, Nicaragua are launching their internship program! They are looking for a Wood Working and Food and Fermentation Intern. Help them spread the word and find some talented folks to join their project!
Abrazos
The Ranch Crew