Most citrus have two lots of blooms a year and hence almost constantly have fruit at some stage of development. Growth will be slower over winter so only water sparingly and never let the roots get waterlogged. They will need protection during winter so greenhouse, conservatory or a well aired windowsill is pretty essential. Give the plant as much light as possible but avoid draughts and hot/cold shocks from radiators, doors and other hot/cold sources when indoors. Use a balanced feed fortnightly in winter and a higher nitrogen feed weekly in summer. Dappled light shade is best if they are outside during summer. They also like a daily misting with water after the sun has set. Calamondins are beautifull plants and always have some interest whether it's fruit or the highly scented flowers. They can get a fair size, ~2m or more, but any prunings can be made into cuttings.