Also, there is no great demand or availability for chemical herbicides, as weeds are easily controlled by hand weeding. Inter-cropping is commonly practiced, and vegetation stories are sometimes used with taller trees and plants acting as a protective canopy for lower crops. Farmers often maximize the use of land by cultivating crops which produce in the ground, on the ground, and above the ground. A popular combination includes cassava, which provides abundant shade, sweet potatoes, which provides good ground cover, and occasionally beans, which fixates the soil with nitrogen. The popular gardens have not been problem-free.
Gardeners have several resources to help address their problems.
These clubs pool resources and experience, and facilitate the dissemination of information and technical knowledge among gardeners. Clubs meet regularly to exchange seeds, produce, tools, and ideas, and some organize workshops on organic gardening and events to involve and educate the community, and maintain model gardens. When necessary, clubs organize regular watch duties to guard gardens from robbers. Today, there are over 400 horticulture clubs in Havana registered with Ministry of Agriculture. These centers sell agricultural supplies to the public that would otherwise be difficult to obtain during the Special Period, such as vegetable and medicinal seeds and seedlings, biological pesticides, organic fertilizer, and tools.