If sunflowers (helianthus) wither in the pot, many hobby gardeners ask themselves whether they should be cut off or left standing. Read the answer here.
In a nutshell
- Difference between annual and perennial Helianthus species
- some should, others can be cut off
- good reasons for cutting and leaving
Table of contents
- energy and nutrients
- Perennial Sunflowers
- Annual sunflower classic
- frequently asked Questions
energy and nutrients
For most plants, it is advisable to cut off withered or faded plant parts. Even if they lack the leafy green or liveliness, the roots will still make them Conserve energy and nutrients as long as the supply lines are still permeable and have not dried out are.
As a result, less energy and nutrients are available for the other parts of the plant. This is often the case when the flowers form and flowering time noticeable. In these phases, the energy and nutrient requirements are particularly high. Dried and withered plant parts are therefore cut off. This way they no longer pull unnecessary substances and there is more energy and nutrients available for growth and more flowers.
Perennial Sunflowers
The classic, annual sunflower and the perennial specimens, such as Jerusalem artichoke, are not to be confused (Helianthus tuberosus), willow-leaved and small-flowered sunflowers (Helianthus salicifolius and Helianthus microcephalus). The bloom of Jerusalem artichokes should be cut off long before they wilt so that the tuber can grow optimally. In the case of perennial ornamental sunflowers, the withered blossoms should be cut off regularly for the reasons mentioned to improve the supply to the plants and to encourage renewed flowering.
Tip: Perennial sunflowers often grow very luxuriantly, so pruning green parts of the plant is recommended, especially if there is not enough space in the pot.
Annual sunflower classic
With the classic annual sunflowers, the energy and nutrient savings are different for several reasons.
These sunflowers usually only have one flower head. In this there are up to 15,000 small inflorescences, but they cannot be cut off, which is why the flower head should be viewed as a whole. If a sunflower fades in the pot, no further flower heads have to be supplied by the roots and it is not necessary to cut them off.
A sunflower in a pot will not bloom a second time either, so this could be stimulated by cutting it off. On the contrary, because as soon as the sunflower begins to wither, the other green parts of the plant slowly die off as well. There can therefore be no bottlenecks in the energy and nutrient supply due to faded flower heads, which is why cutting them off is not necessary. Nevertheless, truncation can be useful:
1. optics
While one or two withered flowers are hardly noticeable in the bed under the protection of several Helianthus annuus, in the pot it usually stands as a solitary plant and the "poor" condition is quickly apparent. A cut off is then a purely optical concern.
2. seed distribution
The seeds of this type of sunflower can pose a problem. These ripen in the flower heads after the flowers have withered and thus have an ideal ripening point for propagation. If you want to use the seeds for targeted, controlled propagation, you should collect them. But if you leave the withered flowers standing without collecting the seeds, you have to expect uncontrolled growth in the garden and even in the surrounding planters in the following year. The seeds are scattered in all directions by the wind and birds. If you do not want this, you should always cut off the withered flowers.
Tip: Sunflowers are as cut flowers very popular and should therefore be cut off as soon as flowering begins. They are practically a must for the autumnal decoration of the home, with dried sunflower blossoms in particular being particularly durable.
frequently asked Questions
Because the single-stemmed plant dies completely after the flowers have withered, you can cut them off just above the ground. You can also cut off directly under the flower and let the remaining parts of the plant die in the pot. If you want to use the same soil for planting the following year, the dead plant parts serve as valuable fertilizer that comes close to compost.
Depending on the variety, they bloom mainly between June and October; the Jerusalem artichoke even blooms into November. The single-stalked specimens have the longest flowering period with a flowering period of up to ten weeks, such as the classic, annual Helianthus annuus, while the others may bloom more frequently during the season and therefore no information on the timing of wilting can be given are.
To prevent the seeds from spreading, sunflowers should be cut off at the latest when a third has faded. Then the seeds are usually not developed to the point where they are interesting for birds or capable of germinating.
As already mentioned in the article, some sunflower owners wish the propagation through natural seed distribution. However, numerous bird lovers also advocate leaving them where they are, because birds love the sunflower seeds as food.