Citrus is a wonderful indoor plant, just for the marvelous fragrance of the flowers. There is nothing quite like opening the door to your indoor space to the heady scent of citrus in bloom, especially after a dreary winter day.
As early as the sixteenth century, special indoor spaces were built specifically to overwinter citrus trees. These spaces were called orangeries, and were heated with stoves. The buildings were made primarily of brick, with glass only on the south wall, which makes sense when you remember that southern exposure is ideal for such sun-loving plants. As you might expect, royalty owned most of the orangeries.
Nowadays, you don’t have to be crowned head to grow citrus indoors. Nearly any citrus plant can be grown in an indoor space, but there are a few tricks to it. While it is tempting to try your hand at growing a tree from a store bought orange, typical hybridization makes any fruit from such seeds disappointing at best. It is much better to purchase your plants from a nursery, by mail order, or online. This is because such sources will have varieties that are specifically bred for home scale growing. Unless you have a large indoor space with a seriously high ceiling, your best bet will be dwarf varieties, such as the Meyer lemon, the Bearss lime, and the Washington Navel orange.
Most citrus are happiest when grown above 45° F (7° C). They need rich, well-drained soil, in containers that are at least 5 gallons in size. It is important to allow the plants to dry out every now and again between watering, especially during the colder months. However, be careful not to let plants dry to the point of wilting. In the summer, they need more constant moisture.
Citrus must be in a well-lit location and have to be fed regularly. It is safest to use food specifically formulated for citrus plants. Even with the best care, it might take a few years before your citrus plant blooms; be patient, though, because it will be well worth the trouble.
Once you have blossoms, fruit will eventually follow. Nearly all citrus are self-pollinating. However, if you want to make sure you get fruit, you can use a soft paintbrush to do the pollinating yourself. You’ll see tiny fruits starting to form in a few weeks.