Why Isn’t My Orchid Blooming?

Orchids, with their exotic flowers in spectacular shapes and colors, have been bred and hybridized for generations so that these very particular plants grow happily in our homes. These beautiful plants occur naturally across the globe, with the greatest variety from tropical Asia, where rainforest conditions give way to drenching rain cycles and drying out periods.

Orchids can be epiphytic, growing on trees or rocks and absorbing nutrients from rain and the air, or terrestrial, growing from the ground. Many of the popular varieties we find in stores and garden centers are epiphytes. So, mirroring their tropical rainforest canopy climate becomes the gardener’s rewarding challenge.

The reward is the orchid’s lovely flowers and lengthy bloom time, as they bloom for up to eight weeks (and some for months!). While they generally flower only once a year – like many plants – the extended bloom time is unusual and certainly worth the wait. Plus, some easy-care types, like phalaenopsis, can rebloom in optimum growing conditions.

If your orchid isn’t blooming, don’t give up. A healthy plant can live for years, even decades, blooming year after year. A few cultural conditions are primary to healthy growing and initiating blooms. Make slow changes to the growing environment and look for signs of improvement.

The Long Answer

Knowing the type you’re growing can help hone in on specific care requirements. For most orchids, look to light, temperature, and water as particular flowering needs. Fertilizing, repotting, and post-blooming care are also key considerations in the orchid-growing regimen.

Light

Varying Light Preferences

The most common reason for a lack of blooms is insufficient light. Alternatively, too much light will also prevent buds from forming. 

Different species and hybrids require varying amounts and levels of light. For example, paphiopedilums (lady’s slippers) need no direct light, while cattleyas (cat orchids) benefit from lots of light to bloom. Phalaenopsis (moth orchids) need intermediate light and are relatively adaptable to lower light, making them easy to care for. Finding the right amount of light for your species/variety is the key, and there are indicators to achieving this.

Symptoms of Insufficient Light

Leaf color is the most visible factor in determining whether or not an orchid is receiving sufficient light. The leaves should be yellowish, grassy green, not lush dark green. A light-to-medium green leaf with yellow tones is in its natural healthy state. For most orchids, leaves should also be upright or horizontal instead of long and floppy. Droopy leaves indicate that there is not enough light.

A good marker to look for is enough light that allows the orchid to cast a faint shadow. This shadow indicates light is coming through to the leaves and is enough for most varieties.

Lighting Solutions

If your orchid needs more light, try moving it to a brighter spot, like a windowsill facing a different direction, or outdoors in summer. Move it gradually from shade to a sunnier spot, as leaves will burn and lose chlorophyll with exposure if they experience a sudden shift. If moving to a south-facing window, use a curtain or shade as a filter.

If increased natural light isn’t an option, consider fluorescent or artificial grow lights. Orchids shouldn’t receive more than 12 hours of artificial light daily, as a lack of darkness can prevent blooming. Cycles of daylight and darkness are part of an orchid’s adaptive growing cycle, so give long daylight hours followed by night by switching indoor lights off.

Temperature

Orchids rely on changes between daytime and nighttime temperatures to initiate blooming. In the rainforest, temperatures can vary 15-20℉ between night and day.  Phalaenopsis, for example, develops flower spikes in response to a cool period of about two to four weeks with nighttime temperatures of 55-60℉.

After this cool period, it helps to move the orchid to a warmer spot (between 60-80℉) to stimulate flowering. Temperature impacts cymbidium orchids the most, and they need more severe cooling. Move cymbidium outside in late summer/early fall for six weeks to develop flower buds.

Cooler nights allow orchids to set buds. Setting the plant near a cool window benefits it with a nighttime temperature drop, as does lowering the thermostat. A lower temperature, especially in autumn, often initiates the bloom cycle. Keep orchids away from drafts to prevent buds from dropping.

Water

With orchids being tropical plants, we sometimes love them to death by giving them too much water. Fluctuations in water, too, prevent them from blooming.

Epiphytic orchids need regular water, but since their roots are adapted to absorb water from rain and moisture in the air, they won’t survive in consistently wet soil. A well-draining pot and bark-based potting mix is essential to plant health. Sphagnum moss is another potting medium sometimes used for orchids, which holds moisture longer. For bark mix, watering about once a week is likely. Water about every three weeks for orchids in moss to avoid excess moisture.

Water thoroughly when potting media feels dry to the touch. If the mix feels dry at one inch below the surface, it’s time to water. Err on the side of dryness rather than overwatering, but don’t allow media to dry out completely.

Fertilizer

In the wild, orchids receive plenty of nitrogen from raindrops. They also get nutrients from decaying plant material on trees.

As a houseplant with its essential cultural requirements met, they don’t require fertilizer to bloom. It can, however, give a boost for more vigorous blooms. Opt for an organic, balanced houseplant fertilizer and use it at ¼ strength. Apply fertilizer every other week in the warmer months, March through December. Stop fertilizing when the active growing season ends and as temperatures cool. 

Be careful not to fertilize too much. An overload of nitrogen can prevent blooms. A low, balanced fertilizer works well. Once a month, water thoroughly to rinse the roots of any fertilizer salts and deposits.

Repotting

Orchids need space and air circulation to thrive. Has the orchid outgrown its pot? If new shoots are at the edge of the pot or trailing over (or even breaking off), it’s time to repot.

To repot an orchid, remove the plant from its pot and potting media. Trim off any brown roots or declining parts of the plant. After trimming, it may not need a bigger pot – just add fresh bark mix and water thoroughly. You can tell the bark mix is new when it’s firm and chunky (bark chips will be aged but shouldn’t be crumbly). Decaying bark drains less readily and can limit air circulation to roots.

Once repotted into a well-draining pot, resume your normal care routine.

After an Orchid Blooms

Most orchids bloom on new growth. When the blooms fade and drop, the stem will brown. There are two options when it comes to cutting the stem. One is to cut it off at the base, allowing the plant to redirect its energy, rejuvenate, and produce a new bloom spike.

The second method is to cut the stem an inch above the second node on the stem. The stem may regrow and rebloom, although blooms and stems are often smaller than the initial bloom.