General Overview:
The Catasetum orchid is a beautiful species of orchid with vibrant colors, appreciated by growers for its versatility and beauty. This orchid is quite easy to grow if you can replicate the correct conditions. Almost always deciduous, pseudobulbous plants have strict growing and resting periods that alternate each year.
These vibrant plants are native to Argentina, Brazil, Mexico, South America, and Central America, where they can grow in sandy, rocky environments and near ant colonies. This orchid develops fleshy, waxy flowers, and the plants are unisex, which is rare in orchids. Male plants are recognizable by their vibrant colors and large size, while female plants are yellow-green and smaller in stature. Another distinguishing feature that sets this species apart is its ability to eject pollen directly onto pollinators. This care guide can be applied to all Catasetum, Cycnodes, and Clowesetum.
Growth Cycle:
Understanding the growth cycle of Catasetinae is key to successful cultivation. When plants are actively growing, maintain fairly consistent root zone moisture and fertilize regularly to optimize new growth. When plants are dormant, little to no water is needed, as pseudobulbs store sufficient water and nutrients to survive the winter rest.
Early Season:
Catasetums begin their new growth cycle between winter and early spring. As soon as you see new shoots, repot your plants into new media. Last year’s roots appear to deteriorate during dormancy and are not as effective as new roots in absorbing water and nutrients. Whether you repot or not, do not water the plant until the new shoots have developed new roots. The new roots should be 8 to 12 cm long, so for simplicity, do not water until the new top growth has reached a height of 8-12 cm. Do not water until the new shoots are well established.
Mid Season: New roots are established, and plants are rapidly developing their new pseudobulbs. The sudden growth during this 3-4 month period is astonishing: plants often double in size. To keep up with their growth rate, plants require constant moisture and regular fertilization. Normally, they are watered 2 or 3 times a week. A balanced fertilizer at full strength is suitable for this rapid growth, or you can top dress with a controlled-release fertilizer and apply water-soluble fertilizers at a diluted rate, for example, 2 grams per liter. Light levels at or above those recommended for Cattleyas will help ensure vigorous growth and abundant flowering. The fruits of your labor will begin to pay off at the beginning of the flowering season.
Late Season: In late autumn, plants will begin to enter dormancy, caused by pseudobulb maturation, reduced day length, cooler day/night temperatures, and reduced root zone moisture. The first signs you’ll observe on your plants are yellowing and browning of the leaves. As a general rule, this will happen by mid-November, at which point you should stop fertilizing and reduce watering by half. When all leaves have dropped, or by the end of December, stop watering the plants. Watering during dormancy should only be done if the plant’s bulbs have severely shriveled. Usually, a single watering is sufficient to rehydrate the bulbs.
Light Requirements:
Catasetum orchids are sun-loving plants, and in their natural habitats, many species grow profusely in full sun. Unless the strong air movement typical of the natural habitat is available, the grower should also provide some shade. For vigorous spring growth, Catasetum plants should be positioned to receive as much sunlight as they can tolerate, depending on their origin, but as their pseudobulbs mature, it’s worth considering whether male or female flowers are desired.
Catasetums are known to produce either male or female flowers depending on the amount of light and moisture they are exposed to. High light and low moisture tend to induce female flower production, while low light and high moisture produce male flowers.
Temperature Requirements:
These orchids are native to warm tropical areas and grow during the rainy summer months. During this growth period, daytime temperatures between 27 and 38 °C and nighttime temperatures between 16 and 18 °C are beneficial. After maturation, nighttime temperatures can be reduced to 12 °C, with daytime temperatures between 21 and 30 °C. In general, for all but a few species, the grower can consider 18 °C as the ideal minimum night temperature and should not be overly concerned about daytime highs, as long as they remain below 39 °C.
Water Requirements:
Catasetums require abundant water during their growth phase. This begins when new shoots appear with the onset of pre-monsoon rains. Watering should be gradually increased as they mature, towards the end of the monsoon. Once the pseudobulbs are mature, watering should be reduced and spaced out until they start dropping their leaves, which indicates that watering should be stopped completely, except occasionally, to prevent the pseudobulbs from shriveling. It is at this time that they will begin to flower.
All Catasetums grown in pots, baskets, and unconventional containers can be watered daily on sunny days during the growing season, provided that conditions allow them to dry out relatively quickly. For mature potted plants grown in conventional pots, watering should not be needed more than once, or at most, twice a week. These species tend to dry out at least slightly between waterings. When watering, do so thoroughly, allowing water to drain freely from the bottom of the pot after saturating the entire contents or permeating the entire root mass of potted and basket-grown plants.
Humidity Requirements:
The Catasetum orchid tolerates an environment with 40-60% relative humidity during the growing season, but 70% is recommended for optimal development of new shoots and flowering. This humidity can be maintained indoors by placing plants on gravel trays, filled only partially with water so that the plants do not sit in water. Air should always be moving around the plants to prevent fungal or bacterial diseases, especially in high humidity or cold temperatures. Higher humidity increases the plants' ability to withstand and benefit from their light quota and also slows the evaporation of moisture from the potting mix. Higher humidity also reduces the likelihood of spider mite infestations, as these tiny creatures prefer hot, dry conditions.
Fertilizer Requirements:
Catasetum orchids have a reputation for being heavy feeders during active growth, and the concept of heavy fertilization should apply to both fertilizer concentration and frequency of applications. The main goal should be to push the plants to their limit, to make them as strong, healthy, and dynamic as possible. Fertilize with an appropriate formulation at least weekly during the growing season, or fertilize with a weak formula every time the plants are watered. Use a high-nitrogen formulation (such as 30-10-10) with a full range of trace elements during the plants' active growth, gradually reducing it as pseudobulbs form. When the leaves begin to unfold, and well before flowering, add a high-phosphorus formulation to develop large, sturdy pseudobulbs capable of producing robust inflorescences. Any soluble product with a high two-digit N:P:K ratio is a good source of phosphorus. In autumn, with the exception of plants that normally flower in spring, a formulation that promotes flowering should be used.
Recommended Fertilizers:
- Balanced Growth Fertilizer: 20-20-20 (NPK) – 2 grams per liter of water – Spray once every two weeks (14 days) – Only mid-season
- High-Phosphorus Flowering Fertilizer: 0-52-34 (MPK) – 1 gram per liter of water – Spray every two weeks (14 days) – Towards the end of the mid-season
Repotting, Substrates, and Propagation:
Repotting should be scheduled to coincide with the onset of new growth, usually in spring. At that time, new roots will form quickly, and the plants will experience minimal setback. These plants have vigorous root systems and require a rich, moist potting mix, such as coconut husk chips, during the growing season. Many growers grow plants bare-rooted during the dormant period to ensure dryness at that time. Fine-grade substrates are common for smaller pots; medium-grade ones are only used in larger pots. Sphagnum moss is used successfully in many areas, as it offers enormous water and fertilizer retention capacity.
Once well-grown, these orchids can be divided into a mature pseudobulb and will flower on the next mature shoot. Hanging pots or mounts are best as they provide good air circulation around the plants. Remember that hanging plants will require more frequent watering: two or more times a day in warmer weather. A good compromise is to place plants in hanging baskets. This offers the advantages of both pots and mounts. Some people prefer to repot plants annually at the beginning of the growing period for better results.
Catasetum Pests and Other Related Problems:
Fungal and bacterial diseases are common for Catasetum due to the humidity levels and substrate they need to survive. Fungal agents cause problems such as root rot, leaf spots, leaf dieback, and flower spots.
Spider mites are very harmful to these crops.
