Tithonia, Mexican sunflower

If you want a plant that attracts butterflies try some tithonia or Mexican Sunflower (Tithonia rotundifolia).  These stately plants are a magnet for butterflies and other pollinators and also look great in the border.  They are large plants, easily 6 feet or more tall and 2-3 feet wide so make sure you leave plenty of room for them.

Tithonia is related to the sunflower and is native to Mexico and Central America.  It’s an annual plant so it can be grown in almost any garden although since it’s a late season bloomer northern gardeners may want to start it inside 6-8 weeks before the last frost.  ( In frost free areas tithonia is a short lived perennial.)

The leaves of tithonia are oval to triangular in shape, rough feeling, with hairs on the backside.  Some leaves may be lobed, and the leaves have a serrated edge.  The plant makes thick stalks with several branches.  In moderately fertile soils, with full sun and on the dry side the plants generally support themselves.  In wetter, very fertile soil some staking may be needed.

The flowers of tithonia are daisy like and normally bright, flaming orange, although yellow varieties exist. (Tithonia diversifolia has yellow flowers and is sometimes found in catalogs.) They are about 5 inches across and have a raised center clump of yellow stamens.  They begin blooming in mid-summer and bloom until frost.  Tithonia seeds look like small sunflower seeds and are enjoyed by birds.

Tithonia seeds are easy to start and in many areas plants are hard to come by so gardeners will probably need to start them from seed.  You can start them where they are to grow or start them inside in pots 6-8 weeks before your last frost is expected.  Plant tithonia seeds or plants outside after the danger of frost has passed.  Thin plants to at least 2 feet apart – they grow quickly and become quite large.

Tithonia will grow in almost any soil, as long as it’s well drained.  They will tolerate partial shade in the south but bloom best everywhere in full sun.  They will tolerate dry conditions quite well.  Fertilization is seldom needed and plants that are fertilized or grown in very rich soil tend to be floppy and have fewer flowers.

Few insect or disease problems are noted in tithonia although Japanese beetles and slugs sometimes bother them.  Keep plants dead headed to prolong bloom.

Herbal and other uses of tithonia

Besides drawing butterflies and looking beautiful tithonia makes a good cut flower.  In Mexico the plants are fed to rabbits and goats.  There are no known human food uses and the taste of the plant is said to be very bitter.  Dried stems are used as fuel. Tithonia can be grown as a living fence and is said to be a good cover crop to improve soil.

Indigenous uses for the plant include a malaria treatment from leaf extracts.  Modern medical studies found that plant extracts killed 50-75% of malaria parasites in the blood.  Also an essential oil made from the leaves did have some effect on repelling mosquitoes.

An 80% ethanol extract of the leaves was found in one clinical study to lower blood glucose.  Leaf extracts were also found to have antibacterial properties.

Folk remedies for tithonia also include it’s use on wounds to reduce swelling and pain from inflammation, for constipation, stomach pain and indigestion and for sore throats.

Caution:  the reason tithonia extracts have not been widely used in modern medicines is that chemicals in the plant have been found to damage the liver and kidneys even in moderate doses.  Leave experimenting with this plant to experts.