Tropical food forests are regaining popularity as a great way to start self-sufficient gardening and grow what you eat.
An ideal tropical forest garden will have up to seven layers of plants. There is a canopy layer for large fruit and nut trees, then a low tree layer for dwarf fruit trees. The next layer is the shrub layer followed by the herbaceous, rhizosphere, soil surface, and vertical layers.
The shrub layer is an often forgotten layer in an orchard that can provide an abundant source of edible leafy greens, berries and nutrients for the soil. They fill in space underneath the canopy layer within your food forest.
The following tropical shrubs are the best shrubs for you to include in your Hawaiian food forest.
- Chaya – (Cnidoscolus aconitifolius) is a fast-growing shrub with large dark attractive leaves. It is also called the spinach tree and is native to Mexico. It grows well in most climates; doing well in hot, rainy climates and even those with some drought.
Its leaves and succulent stems are an important source of food. Chaya is rich in protein, calcium, iron, niacin, riboflavin, and vitamin A.
To propagate it, all you have to do is stick a branch in the ground and watch it grow as long as you’re in a moist climate. If you are in a drier climate you may need to irrigate it until it roots.
Chaya grows to about 6-8ft tall and can be harvested as soon as 90 days from planting and it will keep producing for years!! Now that is a plant worth planting.
- Katuk – Katuk (Sauropus androgynus) is an upright shrub with multiple stems and dark green leaves indigenous to Southeast Asia.
Also known as Sweetleaf, Katuk is eaten both raw and cooked. Its shoots, flowers, fruit, and seeds are edible. Katuk can grow as high as 6’ making it a great hedge plant.
Katuk can be harvested in intervals of two months under good conditions or all year round in tropical regions.
While Katuk is considered safe to eat, it is important to note that excess consumption of Katuk is associated with Bronchiolitis obliterans. Cooked Katuk is safer than raw.
I like to use Katuk in soups and curries, that seems to be the best way to cook it for me.
- Callaloo – The Callaloo plant (also Kallaloo, Calaloo, Calallo, or Callaloo) was domesticated in Africa and the Americas and is celebrated in the Caribbeans. This shrub is known for its bright tender leaves that can be lightly steamed nor eaten raw.
Callaloo is a type of amaranth. It is a resilient crop that can be eaten in several ways. The leaves can be seasoned with garlic, onion and pepper then served with breadfruit, saltfish, or boiled plantains.
When planted, Callaloo takes about 30 days to mature. It takes up to 20 days to germinate but it grows rapidly after that. It seeds itself so you can expect many young plants to spring up. A mature Callaloo plant can grow as high as 4’ tall.
Callaloo is wind pollinated and it can cross-pollinate with many other amaranth species. To prevent unwanted cross-pollination, you can cover the flowers with tassel bags.
- Bele – Bele (Abelmoschus manihot) also known as edible hibiscus, sunset hibiscus, muskmallow, aibika or hibiscus manihot; was formerly thought to be a member of the Hibiscus species but is now classified as Abelmoschus.
Bele is a perennial shrub that can grow to about 2-5 meters tall. It is a highly nutritious plant; its leaves are rich in protein, iron, vitamins A and C. Its young leaves, shoots, and flower buds are all edible.
The young leaves and flower buds can be eaten cooked or raw. Its juice and bark are also used to make various medicines. I find the leaf to have a bit of a slimy texture and best used in soups.
The plant is easily cultivated from cuttings but can also be grown from seeds. This plant needs high moisture, high humidity, and stable temperatures above 25°C. They need well-drained, fertile soil and do best in sunny areas.
- Pigeon pea – Pigeon pea (Cajanus cajan) is a woody shrub grown in the tropics and subtropics. Its seed, leaves, and young shoots are edible. Its leaves are used for various medicinal purposes, its stems are used for hatching and making baskets.
Pigeon pea is also planted as green manure. It is a nitrogen fixer which makes it a great companion in an annual vegetable garden or on the sunny edge of a food forest,
Pigeon pea is an evergreen shrub that can grow to about 8’ in height. It can thrive in almost any solid type(sandy, loam, or clay). However, it doesn’t grow in the shade and must be cultivated in a sunny position.
It matures and can be harvested in 3-4 months for the newer varieties and about 6 months for the older varieties.
- Surinam Cherry – Surinam cherry ( Eugenia uniflora) is a shrub grown for its valuable fruit and its beauty. It is a broadleaved perennial plant propagated by seed native to South America.
The shrub grows to maturity in about 5-6 years under favorable circumstances but can take up to 10 years to mature if the terrain is unfavorable.
Its fruit can be made into jam or relish. It can also be made into juice, wine, or vinegar. But if you have kids, expect them to get eaten before they ever make it inside.
- Cacao – Cacao (Theobroma cacao) or cocoa is a tropical evergreen shrub grown for its fruit and its valuable edible seeds. Its valuable seeds can be processed into cocoa powders cocoa butter and chocolate.
The cacao plant grows to about 8-12 ft. It requires a narrow temperature range of about 72-85 degrees Farenheight (20-28 degrees Celsius) to flourish. It also requires soil that is well-drained, porous, and rich in humus.
Cacao plants are vulnerable to pests and disease so special care must be taken while cultivating them.
It takes about four years for the cacao plant to mature and produce fruit. Each shrub can produce about 70 fruits at a time.
- Coffee – Coffee is a great addition to any tropical forest garden. Famous for its seed known as coffee beans, this plant is one of the most valuable plants in the world.
Coffee beans are used to flavor beverages and products and the fruit can also be made into juice.
There are hundreds of species but the two most popular are the Coffea arabica and Coffea canephora. Coffea arabica is preferred for its sweeter taste but Coffea canephora is treasured for its higher caffeine content.
A coffee plant can grow up to 8 ft tall. It produces fruit after 3-5 years and keeps producing for up to 60 years or more. It takes up to 9 months to ripen.
- Tea – Tea plant (Camelia sinensis) is the plant whose leaves are used to produce tea. Tea plants can be grown in a garden if you live in a warm climate, they can also be grown in your home if you live in a cooler zone.
It takes three years for the shrub to be ready for harvesting. The tea plant typically grows to about 3-4 ft but can be larger (up to 20ft in the wild). The plant grows best in deep, acidic, well-drained soil.
Tea plants are a great addition to any tropical forest garden because their leaves drive away pests and their leaves trap Nitrogen.
- Poha Berry – Poha berry (Physalis peruviana) is a fuzzy-leaved shrub that bears small orange berries. Its fruit is tangy and sweet tastes like a mixture of strawberry and pineapple.
Poha berry is cultivated in fertile well drained soil. It is grown from the seed. However it is important to note that seeds will not germinate in cold soil. The fruit should be harvested when the fruit berries fall and the husk turns light brown.
I like to turn the fruit into a jam/marmalade that can taste a lot like green salsa. My kids like to eat it straight off the bush.
Hawaiian Chilli Pepper
- Hawaiian Chili Pepper – The Hawaiian chili pepper (Capsicum frutescens) plant is a large perennial bush that can grow up to 3 ft tall.
Known for its small red potent peppers, this shrub fruits all year round. Its fruit is very nutritious with high levels of vitamin C and A.
They love the sun and can tolerate a lot of rain. Hawaiian chili pepper can live from 2 to 15 years.
- Cardamom – Cardamom (also cardamom, cardamum) is a spice made from the seeds of two plants in the Zingiberaceae family, Elettaria cardamomum and Amomum subulatum.
Its seeds are used to flavor a variety of foods, liqueurs and medicines. It is the third most valuable spice in the world after saffron and vanilla.
You can plant cardamom by getting seeds of any of the cardamom bush specifically sold for planting.
Elettaria cardamomum is also known as green cardamom is the most common. This plant is a 4 to 6ft tall forest-dwelling plant. It is a clumping perennial that regrows each year from its large rhizomes.
Elettaria cardamomum takes 20-40 days to germinate. It favors soil that is rich in humus, well-drained and slightly acidic. It takes about 2-3 years to flower and its rhizomes can live up to 15 years. Elettaria cardamomum needs plenty of water, generous shade and temperatures that are not too chilly.
The seeds can be harvested by hand about 30-40 days after the plant flowers.
Watch out for pests and disease such as thrips, root nematodes and fungi. You can prevent these by keeping the growing area clean and removing dead plant matter frequently.
So there you have them folks…
Other plants you might consider for the shrub layer of your tropical food forest are bananas, cassava and moringa. With proper care and hard work, soon you will have a luscious shrub layer providing food, spices, juices and more.