Mexican Sunflower
Tithonia rotundifolia 'Torch' is the cultivar I grow, and for good reason. It attracts butterflies. The others in the family ususally don't, and I have no space for them. So my expertise is limited to the orange flowered t. rotundifolia Torch variety.
Butterflies such as Monarchs, Gulf Fritallary, Zebra Longwings, Anthanassa frisia (Cuban butterfly), Hummingbird moths, and various Swallowtails love the nectar of these lovely sunflowers. Growing a group or a large bed of them will draw in many different species of butterflies for you and your family to admire.
The Mexican Sunflower Torch does get quite tall. Mine are grown out in 2 foot tall raised beds and easily top 6 feet by summer's end. They do well in a loamy, yet sandy soil, with lots of added compost. Mulch the surface to hold in the waterings. Deep watering several times a week are needed to keep this plant healthy.
I've read it can be grown as a perennial in my zone (10A) and yet mine still die back in late fall. If this is the case with your tithonias, do as I do and save seed from the dried heads. The seeds pull out easily. Collect and allow them to dry out until ready to plant again in late winter or early spring.
There is a trick to getting this seed to germinate. Don't cover the seeds with soil. Tithonia 'Torch' needs sunlight for the seeds to germinate. So simply lay the seed on the surface of the pot (whose soil you have previously soaked well) and mist the seeds. Keep them moist, and the pot in full sunlight until they germinate. Fresh seed sprouts in about 5 days.
Make sure there is only one plant per starting pot. Tithonia are very large sunflowers, and need the room all to themselves. When the seedlings are about 1 foot tall, transfer out to a sunny garden spot you have prepared in advance. Place them about 2 1/2 to 3 feet apart.
Mexican Sunflower grows so large that it has to be staked. Prepare for this in advance of placing them out in the garden. They also break easily in the wind, so don't be alarmed if you find cracked stems. They grow so fast and furious that it is bound to happen.
Tithonia are hungry plants, and will need to be fertilized often. If you are growing them for butterflies like I am, do not use commercial fertilizer. Instead, buy Fish Emulsion. This stinky liquid is like gold to your sunflowers, and will make them flower more often, and grow stronger, and bigger. You can also use mushroom compost and leaf loam to help to naturally fertilize the sunflowers. I fertilize mine about every 6 weeks.
Dead-heading the spent blooms is a must to keep tithonia blooming all spring and summer. Right after the bloom fades, cut the flower from the stalk. This forces the plant to create more flowers for you and your butterflies. At the end of summer, and you want to collect seed, allow some of the dying blooms to remain on the plants. Let them completely wilt and dry up. Then dead-head the blooms and pull the seeds straight up out of the center of the dried flower. The seeds will resemble those of chrysanthemum, or other types of daisies. Store these over winter in a cool, dry place until ready to plant out again.
When the last blooms have died, this annual plant will also die. The large main stem/trunk will brown and dry, as will the rest of the plant. Since the root system is a very shallow ball-shape, it is easy enough to pull up come fall, and throw onto a compost pit, making cleanup of the garden area simple.
Tags: mexican sunflower, tithonia, tithonia rotundifolia, butterfly plant, nectar plant,, mexican sunflower, orange sunflower, butterfly nectar plant,
