Last Updated on October 8, 2022 by Real Men Sow
Iris laevigata, a true water iris, is well-known for its tolerance for semi-aquatic habits. Although it is sometimes confused with other Japanese Irises, this species is ecologically distinct by its preference to have its crown immersed in water throughout the year.
Benefits of Growing the Water Iris (Iris laevigata)
Water iris is a great marginal plant for large or medium-sized wildlife ponds. The water iris’s leaves can be used to blur the edges of your pond, and also hide pond liner or artificial features. The protection the submerged structures can provide may be beneficial to juvenile fish, tadpoles and insect larvae. The stunning iris flowers attract many pollinators. The blooms of this plant are so beautiful that even hummingbirds can’t resist them.
Deer are likely to frequent your garden, so you will be pleased to see that water irises are not a common choice for them. A few water iris patches along the shoreline can be used to prevent erosion and act as a buffer from waves. Are you still not convinced? Water irises are a great backdrop for ponds. They can also help to keep your water clean and provide shelter for visiting waterfowl.
Conditions for Water Iris to Thrive
Water iris thrives in organic soil that is slightly acidic, although it can tolerate slightly alkaline conditions. Because its roots are resistant to rapid drainage, it prefers loamy or clay soils. This species prefers a pond margin over an edge location. The ideal water level should be a few inches above the plant’s base throughout the year. Unfortunately, submergence can reduce survival chances.
Water iris thrives best when temperatures are between 12 and 25°C (53-77°F). The plant might not flower as fast if temperatures drop below this temperature range in summer. If conditions are ideal, however, your water iris might surprise you with another round of blooms in late summer or early autumn. After 2 to 3 years of care, clumps will usually reach a width of 0.5 m (20 inches).
Planting Water Iris (Iris laevigata)
Water iris can be planted with its bulbs, and then propagated by division. You can also grow it from seeds, although this is more difficult and may require several transplantation stages before you are able to outplant. You should sow seeds in soil that is consistently moist. Place small containers (or pots with bottom holes) in small containers on a tray that has a few inches of water. They should start to sprout in 3-4 weeks if the seeds are viable.
When the seedlings have grown sufficiently large to be able to handle, you can transplant them into individual pots. Plant them at least one inch apart if you plan to place them in a shared water basket. For propagating water iris divisions: Place them 18-24 inches (46-61 cm) apart or in their own pond containers. You can use aquatic soil, but these species will be better off with more organic matter. Plant roots should not be submerged below 4 inches (10 cm) of water. As they grow older, they can be gradually moved into the pond.
Once your water iris is established, it will be relatively simple to take care of. You should place it in an area that gets at least 6 hours of sunlight per day, preferably during the morning hours. If you live in an area with hot summers, a partially shaded area is best.
This species might benefit from an aquatic fertilizer with broad-spectrum properties during its growth period, particularly if it is not cultivated in a pond setting. It will not need additional fertilizer if it is cultivated near a fish pond. This is due to the nutrient content of the water. Regularly inspect the plant’s leaves and treat or remove any diseased or pest-infected parts. To maintain the appearance of your iris clusters, you can trim out unused blooms to encourage another flowering period.
Pests You May Encounter
The rice root aphid, (Rhopalosiphum Rufiabdominalis), and the common blossom thrips, (Frankliniella Schultzei). These insects can be controlled chemically or manually once they are spotted. They could quickly infest nearby plants and entire colonies of water iris.
Iris laevigata can withstand winter temperatures below 0°C (32°F). This plant is not able to withstand cold temperatures so it can be kept indoors during winter. Just trim the leaves to a length that lets them protrude just above the waterline. This should be done in autumn, or before the temperatures dip below zero. To prevent pond water decomposition, remove any leaves that are in decline.
The established root systems will produce new leaves once temperatures rise again. The foliage should not be reduced if you live in an area that experiences moderately warm winters. It will still remain green throughout winter.
Is Water Iris (Iris laevigata) Invasive or Toxic?
If Iris laevigata is raised in ideal conditions and rich soils, it can be an aggressive spreader. Its potential to outcompete native Iris species isn’t as serious as it might be. Aquatic baskets and containers are great for managing water iris colonies.
This plant’s organs, like all Iris species, have toxins. They can cause mild symptoms in humans, but more severe effects in animals and pets. Because it contains pentacyclic resinoids and terpenoids, wild animals are advised to avoid this plant. These compounds are often called irisin and iridin. The highest concentrations of these compounds can be found in the bulbs and rhizomes. Ingestion of large quantities can cause nausea, vomiting, diarrhea, and even death. To prevent poisoning, keep curious pets and cats away from this plant.
This species is not prone to contact dermatitis so you can safely touch the plant and use your naked hands. As a precaution, avoid exposing sap-oozing tissues.
Is Water Iris (Iris laevigata) Edible? Will Fish Eat it?
It is not edible, even when dried or cooked. Although Iris plants can be diluted to treat certain ailments, they should not be harvested for infusions or consumption. Don’t worry, this plant is not usually eaten by fish. You can place it along the edge of a Koi pond. It is unlikely that koi will graze its organs.