Pollination is the transfer of pollen from the male to the female reproductive parts of a plant. For philodendrons, manual pollination is undertaken to achieve specific breeding goals, such as developing new varieties with unique traits, or to produce seeds for propagation. While philodendrons can be propagated by cuttings, obtaining seeds through pollination offers genetic diversity and the creation of new plant forms.
Understanding Philodendron Flowering
Philodendrons produce a specialized flower structure called an inflorescence, consisting of a fleshy spike (spadix) encased by a leaf-like hood (spathe). The spadix contains female flowers at the base, sterile male flowers in the middle, and fertile male flowers at the top. This arrangement, along with a unique timing mechanism, prevents self-pollination.
Philodendrons exhibit protogyny: female flowers on an inflorescence become receptive before male flowers on the same inflorescence release pollen. This asynchronous development favors cross-pollination, promoting genetic diversity. The female phase occurs first, often lasting a few hours, followed by the male phase and pollen release, typically 24 to 48 hours later. Understanding these distinct phases is essential for successful manual pollination, as it dictates the precise timing for pollen collection and application.
Steps for Manual Pollination
Manual pollination requires careful observation to identify the plant’s reproductive phases and a few simple tools. The process begins by recognizing the receptive female phase, often signaled by the spathe partially opening to reveal the spadix. During this phase, female flowers at the spadix base may appear sticky or glistening, indicating their receptivity. Some philodendron inflorescences can also generate heat, a sign of their receptivity and readiness for pollination.
Following the female phase, the inflorescence enters its male phase, typically a day or two later, when male flowers release pollen. This pollen appears as a fine, powdery dust on the spadix. To collect pollen, a soft brush, such as a small artist’s brush or a cotton swab, is effective. Gently brush the male flowers to gather the pollen, which can then be stored in a sealed container and refrigerated for a few days to several weeks.
Once pollen is collected, apply it to a receptive female inflorescence. Using the same soft brush or a fingertip, gently transfer the pollen onto the sticky female flowers at the spadix base. The optimal time for application often coincides with the female phase, which can occur in the late afternoon or early evening, and some sources suggest early morning (1-4 AM) for certain species.
Post-Pollination and Seed Collection
After successful manual pollination, observable changes indicate fruit and seed development. Within a week or two, the inflorescence base, where the female flowers are located, will begin to swell. This swelling signifies that fertilization has occurred and the fruit, containing the seeds, is beginning to develop. If pollination was not successful, the inflorescence will typically decay.
The fruit development period varies among philodendron species but generally takes several months, often ranging from six to twelve months. The fruit ripens when it softens, changes color (often to yellow or orange), and may emit a sweet fragrance. It is important to wait for full maturity to ensure viable seeds.
To extract the seeds, mash the ripe fruit and separate the seeds from the pulp, often by rinsing them in water. Viable seeds tend to sink while pulp floats, making separation easier. After extraction, spread the seeds in a thin layer to dry in a well-ventilated area. Philodendron seeds should not be allowed to dry out completely, as this can reduce their viability. Once cleaned and dried, the seeds can be sown for propagation.