If you are growing your orchid in tree bark or another well-draining medium, you should provide copious amounts of water to soak the roots. After soaking the potting mixture well, allow the excess water to drain out of the pot. This will ensure the return of that all-important airflow to the roots as well as flushing the growing medium to prevent the buildup of mineral salts. Just be sure that you never leave the roots soaking for more than about 15 minutes, as they will start to become waterlogged if you do.
The second type, the nobile Dendrobium, grow warm in the summer but require a cool winter period to induce flowering. They need to experience temperatures in the 40s to low 50s (preferably) in order to flower well. They are distinguished by bearing fuzzy, flat, round, colorful flowers close to stem, which cover most of the stem on a well-flowered plant.
The vast majority of orchids grown in the home are epiphytes, meaning they live in nature by clinging to trees or even stones. The roots of these plants are highly specialized organs that differ dramatically from normal plant roots. Of course, it's hard to generalize about anything when it comes to orchids. This is the single largest group of plants in the world, so for every rule, there are 100 exceptions.
Do a finger test. This is the best way to determine whether an orchid needs more water. Stick your pinky finger into the potting mix, taking care not to disturb the orchid's roots. If you don't feel any moisture, or you feel just a little, it's time to water the orchid. If you feel moist potting mix right away, give it more time. When in doubt, you should wait an extra day.
The amount of drainage your pot has will depend on the size of the pot, with larger pots requiring more drainage holes than smaller pots. Since orchids prefer to grow in smaller pots, a good rule of thumb is to make sure the pot has 4-8 holes if it’s 4 inches (10 centimeters) or so, while larger orchid pots (around 6 inches or 15 centimeters) should have 8-12 holes for drainage.
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.