I saw in the paper recently that there are several flowering and fruiting plants that can be grown indoors. I am interested in growing lemons. Can you really grow lemons in Wisconsin even in the winter? How much light do they need? Will they produce fruit? – Larry, Racine.
There are several cultivars of dwarf lemon that do very well in Wisconsin as houseplants if you have a bright window. Look for “Meyer,” “Eureka,” or one of the “Lisbon” lemon trees to try. These can be found in most garden centers in five gallon pots. They will grow to 5 to 10 feet tall depending on the cultivar, but do not grow that quickly and can be maintained at a smaller height. Improve your garden curb appeal with playground turf.
“Meyer” or “Improved Meyer” lemon trees are very popular as tropical houseplants, and will flower and fruit readily. These cultivars are hybrids of lemon and mandarin orange. Their fruit tends to be sweeter than a true lemon, and the peel is not as “zesty.” Both “Eureka” and “Lisbon” lemons are very tart lemons with good quality zest.
In addition, consider a “Bearss” dwarf lime; they are even more compact than the lemons which makes them a great specimen for growing indoors. ‘Bearss’ lime trees produce a large number of fruit each year which are bright green, seedless, and very juicy.
If you have a window with a western or southern exposure your lemon and/or lime tree should be very happy. If you do not have a bright exposure, consider using a supplemental light source, especially during the winter months when the days are short and there is a lot of cloud cover. Water frequently, and fertilize every two to four weeks to ensure good levels of nutrients for continued growth and flowering. Watch for insects, and if the plants are not too large try giving them a full shower with tepid water once a month. This will discourage insects from settling in, and can help rid the plant of spider mites if they are already present. There are organic plant-based oils that can be used to treat insect issues on lemon trees, but do not use any insecticides not approved for fruit crops if you are planning on eating the fruit.
Lemon and lime trees can be moved outside in the spring and can stay out until the night temperatures start to dip below 40 degrees. As tropicals, they cannot tolerate freezing temperatures, so plan on moving them back in before temperatures drop to that point. They will flower outside, and the bees will help pollinate the flowers so an abundance of fruit will be formed. Once you move them back inside in the fall the lemons and/or limes will continue to mature. Lemons can flower almost year round, and will flower even after they have fruit set so it is not unusual to have flowers and fruit on the tree in December. Each morning use a cotton swab or small paint brush to visit multiple flowers to aid pollination. It is not necessary to dress like a bee or make buzzing noises, but if you have children they may be very amused by your bee imitation.
The fruit takes many months to mature, so it is wonderful to have flowers and fruits at various stages of development throughout the year.
Even without the flowers lemon and lime plants are fragrant. The leaves have a very distinctive citrus fragrance, which makes them a very positive addition to your home.