Paul Knight, Merrifield Plant Specialist
Perhaps one of the most well-known houseplants, orchids are loved for their elegant beauty and long-lasting blooms. These plants have a reputation as an intimidating plant for advanced gardeners only, but with a little extra knowledge, anyone can help their orchid thrive.
If you are an orchid beginner, we recommend starting with the Phalaenopsis orchid. This is one of the best orchids to grow as a houseplant since it thrives at average household temperatures, and it does very well sitting on a windowsill. These plants can bloom 2 to 3 times per year after they are established.
Phalaenopsis orchids need about 3 to 4 hours of either morning or late afternoon light. For this reason, an eastern facing window works best, but a shaded south or west facing window are good as well. If you are having trouble getting your plant to rebloom, try increasing the amount of light it receives by removing shade, placing it closer to the window, or supplementing its light with a grow light placed 8 to 12 inches above its foliage. You will know your plant is receiving too much light if it’s leaves become red-tinged. If that happens, reduce the amount of light it receives.
When purchasing your plant, determine whether your orchid is planted in moss or bark. Orchids should only be watered when they are nearly dry, but should never be allowed to dry out. As a general rule of thumb, when the plant is planted in bark, water every 7 to 10 days. When it is planted in moss, water ever 10 to 14 days. To prevent rot, water your plants in the morning so that the leaves are dry by the evening. Orchids also love humidity, so you can place them on a humidity tray or a tray of gravel partially filled with water to create a more humid atmosphere around them.
If your plant is growing in a bark-based media, a high nitrogen fertilizer (30-10-10) is a good option. We recommend using a blossom booster fertilizer (10-30-20), which gives a better bud count when it comes to bloom time for orchids.
We recommend placing orchids on a windowsill for a good temperature differential between day and night. This encourages rebloom. One of the primary reasons our customers are not able to get their orchids to bloom a second time is a lack of cooler air in the evenings.
While this temperature difference is great for the plants when initiating blooms, once the buds have formed and the plant is ready to bloom, you should move it away from the window as temperature differentials can cause already formed buds to drop.
Flowering and Repotting
After your Phalaenopsis orchid has finished blooming for the first time, cut the stem back to the third node from the base of the stalk. A new flower spike should emerge in a few months. The moss and bark materials that orchids are grown in break down over time, so you should repot your orchid every 2 to 3 years in the spring, or in the fall after it finishes blooming. You will know your orchid needs to be repotted when the potting medium breaks down and begins to look like dirt, or the roots begin to show at the top of the pot.