most eucalyptus even the smaller growing ones are rather vigorous to be kept as shrubs without fairly frequent pruning and shearing to keep them in the desired space. assuming you live in an appropriate climate (roughly USDA 8 and up) you might consider planting bottlebrush/callistemon instead---they are related to eucalyptus, have similar drought and heat tolerance AND usually are more shrub like in growth with pretty flowers as well. hope this helps.