One of my favorite annuals for attracting butterflies is the Mexican sunflower (Tithonia rotundifolia) seen above. It's one of those annuals that everyone appreciates in the summer garden but few are familiar with the value of this species for attracting a wide range of butterflies, particularly monarchs. Most seed catalogs carry various selections (orange and yellow blooming) of this heat tolerant, full sun annual but you will rarely see it offered in spring as a plant in a greenhouse as it doesn't show the enticing blooms until late July. It is easy to grow from seed once the soil warms and it will grow rapidly with stems and foliage filling out quickly. Patience is important as the payback for waiting is worth it! Though drought tolerant, adequate moisture and decent soil will benefit this plant and the taller varieties may require staking in areas unprotected from high winds (stem breakage). Flowering in our summer gardens for Mexican sunflower will continue in to late September and sometimes early October. Above and directly below is the variety 'Torch' which is an All-America Selections (AAS) winner from 1951. That seems like a good track record for this variety which I've grown every year I've been involved with public gardening (18 years?). This aster family member can fill some space with taller varieties like 'Torch' and 'Yellow Torch' getting 5'-8' easily in a good summer. Keep in mind how big and lush these will get by even mid-summer. Strong stems and "felty" leaves are additional features but the flowers steal the show of course. There are more compact varieties that are in the 3'-4' range like 'Fiesta Del Sol' (AAS winner in 2000) seen further below. There are some compact yellow varieties too and you can purchase a blend that features a mix of yellow and orange blooming varieties ('Arcadian Blend'). Despite seeing over a dozen varietal names over the years, it boils down to tall orange, medium orange, tall yellow and medium yellow for heights. They are wonderful in the late season garden and the orange varieties were a big part of our orange-themed entrance garden in 2013. I don't use the yellow varieties much as there are plenty of other tall yellow blooming annuals (zinnias, etc.). Don't neglect to pick up some Mexican sunflower (Tithonia rotundifolia) seeds this year and enjoy teasing the monarchs with an eye-catching, tasty treat.
We had some more great help today. Patrea (above) helped paint Adirondack chairs for the North point garden and dabbled in both green and yellow today! Dr. Gredler (below) kept busy with painting after getting a good stir on this gallon of yellow paint. Doc's paint clothes are a definitive, historical reference to the colors that we use each winter for our chairs, containers and obelisks. The second photo down shows Pat processing more lights. Ron W. and Urban came in to help Pat out with this task (easier with multiple helpers...or a ladder as you see in the photo!). Pat also headed out in the gardens to bring in more lights. Bill O. was in later to help shift processed lights to storage, etc. The third photo down shows Mark S., the RBG maintenance guy, at the Horticulture Center where he was picking up some supplies. Maury ran some errands for us today. We also saw Big John, Deb G., Pearl & Don C., Kay and Tom C.
'Torch' Mexican sunflower (Tithonia rotundifolia)
close-up of above (youngest blooms the darkest)
'Torch' Mexican sunflower (Tithonia rotundifolia) taking up some real estate in late summer
note 'Torch' in the back center of this composition at RBG (2013)
'Fiesta Del Sol' compact Mexican sunflower (Tithonia rotundifolia)
same as above at the Chicago Botanic Garden
'Yellow Torch' Mexican sunflower (Tithonia rotundifolia)
compact yellow Mexican sunflower (Tithonia rotundifolia), unknown (forgotten) variety - rare!