Professionals have rarely seen trees as savings banks for poor people. But while trees and their products have become more valuable and easier to market, many poor people have become more vulnerable as contingencies cost more and traditional supports weaken. Consequently, trees have increasing importance and potential as savings and security for the poor, and for use to meet contingencies. For savings and security, trees compare quite well with jewelry, large stock, small stock, land, and bank deposits. Disadvantages of trees can include insecure or unclear rights, restrictions on cutting and selling when needed, and problems with marketing; but common advantages include cheap and easy establishment, rapid appreciation in value, divisibility to meet needs closely, and regeneration after cutting. More empirical studies are needed on the use and potential of trees as poor people's savings banks. The policy implications of present evidence and analysis include tree reform, improved marketing and prices, and above all investing poor people with secure and full ownership of trees, with rights to harvest, cut and sell similar to the withdrawal rights of depositors in savings banks.