Louisiana Irises

ABOUT LOUISIANA IRISES

The peak blooming months for LOUISIANA IRISES in Australia are October to November.

Louisiana Irises are an evergreen perennial that originate from the wetlands of Louisiana, Texas & Florida of U.S.A. They are a swamp iris that prefer wet or damp conditions that grow best in full sun or part shade. Under trees where they get morning or afternoon sun is suitable. They are fast growing, easy to grow, hardy and vigorous.

Throughout the year Louisiana Irises put on a handsome display with their attractive blue-green sword like foliage. Frogs love to live amongst them.

Louisiana Irises come into bloom during spring where each stem/scape may have up to 20 or more blooms, each bloom lasting for several days. They make great cut flowers. They look tremendous growing in old bathtubs, troughs, containers, alongside creeks, dams, ponds and used in water features.

PLANTING OF RHIZOMES

If planting in ponds, dams or creeks - plant the rhizome around the edges at high water mark just below the surface of the soil. You can secure the rhizome by staking them to the ground around the rhyzome, using a strong piece of bent wire (tent peg, or wire from a coat-hanger) taking care not to pierce or damage or pierce the rhizome. Once the plant has established you can remove the wire and it will grow unaided. Make sure to keep the soil damp through the summer, dry hot seasons as the rhyzomes may shrivel up. They love damp feet all year round.

If planting in the middle of a pond, plant rhizome in a suitable size pot and have pot raised by bricks so that the rhizomes are just below the water surface, DO NOT submerge the foliage more than a couple of inches for a long period of time under the water.

If Planting in Tubs - I like to have mine planted about 1-2 cms below the soils surface. You may like to add some mulch over the summer months which protects the rhizomes from the heat and direct sunlight, this also retains the moisture for longer. Mulch also protects against frosts and extreme cold during the winter months.

If planting in garden beds, and you experience hot long dry summers like we do, make sure they require dampness throughout the summer, so to obtain this you can dig a trench of a couple of feet deep and line with plastic, fill with composted soils and plant your rhizomes out. I grow all mine in big plastic containers in the nursery. At home I grow in regular garden beds, making sure they get watered during the summer months and in my fishponds.

CARE & FERTILIZING

I find these plants are very easy to grow and care for. I don’t use anything on them for pests as they are pretty pest free.

Louisiana irises generally like a soil with a PH of 6.5 or less and need to be fertilized at least twice a year. It is important to remember that Louisiana Irises are acid loving plants and DO NOT TOLERATE LIME. Avoid using rose fertilizers, potash and mushroom compost and remember to never use lime. I usually throw a handful of dynamic lifter and some cow manure on my plants and that’s pretty much it. I fertilize my Louisiana Irises once a year leading up to blooming season, around Mid-Winter before the scapes start appear.

You can use a slow release fertilizer or a handful of Azalea & Camellia fertilizer or Blood & Bone. A good sprinkle of dried up cow/horse or pig manures or any organic matter like compost, straw, leaves, wood chips.

I don’t water in winter as we get sufficient rain and will only water in summer when I think they need it which mights be weekly.

Given the little attention they require, they will in return reward you with a magnificent display of healthy, colourful, good sized blooms from early to late spring.

Generally they are rampant growers and very quick multipliers, therefore needing to be divided and replanted after a few years if you are short on space.

PESTS & DISEASES

These are pretty disease free plants. The foliage may tan off or get black spot during the summer months. To avoid these avoid overhead watering during the hot summer/ humid months. I water the plants at the base with the hose as I have all mine growing in containers. They may start to look a bit unsightly with the old foliage dying back in Autumn, then the new foliage starts to appear late winter early spring.

You can either leave the dying foliage or trim back if becomes unsightly.

If you do see any leaf disease, remove and destroy the affected area by cutting it back to the healthy green foliage. This should be done as soon as possible. A good fungicide spray like “Mancozebe” will get rid of any undetected traces. Personally I haven’t had to do this.

Slugs and snails LOVE to eat the blooms so to avoid this happening I sprinkle a handful of snail pellets out whilst thescapes start to form before the blooms start to open. I don’t really have a problem with slugs or snails either.

Happy Gardening - Shelli Green