Pollinators are often visually attracted by the shape and colours of the labellum. However, some Bulbophyllum species attract male fruit flies (Bactrocera spp.) solely via a floral chemical which simultaneously acts as a floral reward (e.g. methyl eugenol, raspberry ketone, or zingerone) to perform pollination. The flowers may produce attractive odours. Although absent in most species, nectar may be produced in a spur of the labellum (8 in the illustration above), or on the point of the sepals, or in the septa of the ovary, the most typical position amongst the Asparagales.
^ Guillaume Chomicki; Luc P.R. Bidel; Feng Ming; Mario Coiro; Xuan Zhang; Yaofeng Wang; Yves Baissac; Christian Jay-Allemand & Susanne S. Renner (2015). "The velamen protects photosynthetic orchid roots against UV‐B damage, and a large dated phylogeny implies multiple gains and losses of this function during the Cenozoic". New Phytologist. 205 (3): 1330–1341. doi:10.1111/nph.13106.
Some orchids mainly or totally rely on self-pollination, especially in colder regions where pollinators are particularly rare. The caudicles may dry up if the flower has not been visited by any pollinator, and the pollinia then fall directly on the stigma. Otherwise, the anther may rotate and then enter the stigma cavity of the flower (as in Holcoglossum amesianum).
The goal is to get each mix particle to absorb as much water as possible. To give the potting mix enough time to absorb water, place the entire pot in a bowl of water for 10 to 15 minutes, then lift it out and let the excess water drain before putting the pot back in place. This technique works well for orchids potted in clay. Since clay is porous, water penetrates the walls of the pot and is absorbed by the bark.
The most important thing to know about how to water phalaenopsis orchids is that you should only water the roots, making sure to leave the crown (leaves, flowers, and stem) dry. Moisture on these parts of the plant can cause problems such as mold, fungus, and tissue rot – especially if water gets trapped in pockets such as those that form where there’s new growth. If you do get water on any part of the crown, use a paper towel to remove the moisture.
Most orchids we grow indoors come from the tropics, and most parts of the tropics are much more humid than the average living room. Orchids grow better if you can boost the humidity in their immediate growing area by grouping your plants together, or placing them on a dry well. Create a dry well by placing plastic lattice or pebbles on a tray, then adding water to just below the lattice or top of the pebbles. Place your potted plants on top of the lattice or pebbles. Learn even more tips for keeping your orchids healthy.
Most orchids are not heavy feeders. Many orchids bloom year after year with no fertilizer at all. During active growth, when new leaves are being produced, you may fertilize every other time you water at half the strength recommended on the fertilizer package. However, it's important to deliver water without fertilizer at least once a month to flush excess fertilizer salts from the bark mix and avoid fertilizer burn to the roots.