The desert spoon is a desert plant related to agave and needs very well drained soil and loves heat. The lower leaves are the oldest leaves so they turn brown and fall off naturally as they age. This may also be a sign of too much water or poor drainage especially if a lot of leaves, such as more than half are turning brown at the same time. Take care when removing these brown leaves as the sharp edges of this plant can cut the skin. Cold weather is another cause of dead foliage on the bottom of the plant. This plant does best in rock gardens and southwest desert landscapes. Keep growing, Marianne Binetti