Plant life has more central significance than animal life to the Zaramo, given that their food is obtained primarily from agricultural activities. The Zaramo cultivate more fruit trees than other inland tribes do, and they transport large quantities of oranges and mangoes to Dar es Salaam markets, which brings them a considerable cash income. Coconut trees also produce fruit that is both consumed and sold. After cashew-nut processing plants were built in Dar es Salaam, cashew-nut trees became of considerable value to the Zaramo economy. During the early days of British colonial administration, the Zaramo were encouraged to raise cotton as a cash crop. Agricultural officers failed to give good instructions, however, and cotton raising failed. Instead, the Zaramo began to grow rice, which became a successful crop that is now being sold to the city.
Early explorers passing through Zaramo country mentioned the fertility of the soil. Traveling through the Ruvu River Valley, they noticed that the land was well watered. Rice, tobacco, maize, beans, sweet potatoes, pineapples, jackfruits, plantains, limes, kapok, mangoes, sugarcane, cassava, curry spices, eggplants, and cucumbers were grown in the area. Tsetse flies were prevalent, and consequently the Zaramo did not have cattle. Nevertheless, they raised sheep, goats, and chickens.
The Zaramo were involved in long-distance trade and slave trade in the nineteenth century. They demanded payment from all caravans that passed through their land, and they were themselves expert slave hunters. The Zaramo leaders not only sold slaves to Arab and Swahili traders on the coast but also kept some slaves for their own use. They also traded in ivory, salt, fish, gum copal, and rhinoceros hides.