A few weeks ago, I was looking through the seed display in the local hardware store. One of the flowers in the display was something I had grown a long time ago but have not grown since — tithonia.
As I held the seed packet, deliberating whether to buy it, I tried to figure out where I could put it in my relatively crowded, small, town garden. Tithonia is a large plant, growing from one to almost two metres in height. Where could I put it? Then I thought of the perfect place — if I bought the seed — which I did!
In my garden I have a hot, dry bed on the south side of mature spruce trees. It has some heliopsis, lilies, solidago and yellow verbascum in it but I always like to add a few tall annuals for some late-summer colour. The last few years I have grown tall red salvia, but although they looked good and were the right size, they suffered from the dry conditions of the bed. I was constantly watering them as they were not nearly as drought-proof as their companions. Tithonia might solve this problem.
Tithonia is a member of the sunflower family and is often referred to as Mexican sunflower. The large daisy-like blooms can be orange, yellow or red. I prefer the red variety — “Torch” — and luckily that was the variety offered in the seed display. I have grown the yellow one — “Goldfinger” — but wanted splashes of red in an otherwise yellow/gold border.
The flowers of tithonia are not as large as sunflowers, only getting about six to eight centimetres across. They will provide good colour in my border and be just the right size to use as cut flowers in arrangements for the local autumn horticultural show.
I will only need to sow a few seeds as these are large plants — from one to almost two metres tall and over a metre wide. Only needing a half-dozen plants, I’ll donate any extras to the Horticultural Society plant sale in May. In a large rural garden a bank of tithonia could be planted, as they look great at the back of a perennial bed or mixed border, planted along a fence or shed, or mass planted in a large island bed.
The growth habit of tithonia is similar to other sunflower plants. The stems and branches are sturdy and the foliage is hairy like the leaves of sunflowers, making the plants unattractive to deer. The flowers are produced on long stems and deadheading of spent blooms will keep the plants flowering right up until frost. Tithonia is not particularly frost tolerant and doesn’t like cool weather, performing best when the temperatures are hot. For this reason, tithonia should not be planted outdoors until temperatures are consistently above 10 C.
Tithonia is easy to grow from seed which can simply be scattered on top of some sterile soilless mix. Enclose the container in a plastic bag to keep the planting medium moist. The seeds need light to germinate so I’ll place the container under the lights of the light garden, which will also provide enough warmth to encourage germination. The seeds should germinate within about a week, so should be started about six to eight weeks before the transplants will be planted outdoors.
When the seedlings get their first true leaves they can be transplanted into individual pots. I try to give them as much light as possible so they don’t get leggy — first in the light garden and later in my cold frame on the back patio. Potting them individually will enable them to be transplanted into the garden with minimum root disturbance. My plants will be in the cold frame for a couple of weeks in early May before they go into the flower border.
The plants like full sun and well-drained soil. Space them about 50 cm apart and water the newly transplanted seedlings regularly until they get established, and then only during really dry weather, as they are very drought tolerant. I’m also going to try one in a mixed container just to see how it performs and how it combines with other plants.
I’m happy to have an opportunity to try out tithonia in my present garden and eager to see how the plants turn out.