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Society for Louisiana Irises Main Sections
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CULTURAL REQUIRMENTS If you have not grown Louisiana Iris before, we trust that this information will assist you to give your new plants a suitable start or encourage you to try them in your garden. The Louisiana iris originates from the gulf states of the Mississippi River in the USA. The plants come to us today from five wild species originally found in the bayous of the Louisiana basin, where natural hybridising occured. The Louisiana iris were respected by the original native inhabitants of the area. Later, pioneer families were also keen to decorate their new gardens with these delightful plants. Just over fifty years ago a special Society was formed by like-minded citizens to preserve the natural habitat of these native plants and to respect them for their inherent beauty and importance in their delicate eco system. The Society for Louisiana Iris was born. Today the Society has members in many different countries of the world, boasts a membership in excess of 500 (I think that's right Pam!) and has provided this website for interested gardeners across the globe to enjoy. Today Louisiana iris have been developed from the original five native species via a process of diligent research by interested and dedicated hybridisers around the world. The Louisiana is the most adaptable of the iris family. No other species of Iris can grow so successfully in such a diverse range of geographical areas. They are happy to grow in naturally marshy or wet conditions, they can grow successfully in a pot in water and they are also just as much at home in an ordinary garden condition. They will tolerate extremes of heat and some cold provided they are mulched against those particular extremes of temperature. They are particularly happy growing in areas which receive considerable summer humidity. This trait sets them apart from the bearded iris varieties, which tend to struggle in these hostile conditions. You can grow Louisiana iris in the garden, in pots, in a pond, in a rockery (to protect the rhizome from extremes of heat or cold) or let them go wild by the side of a dam or water feature. They will adapt quickly to their new environment. The major requirements to grow Louisiana iris successfully include four major components:
b) Acidic soil, fertilizer and mulch are the remaining three components. Louisiana iris respond well to being grown in a richly composted and fertilized acidic soil. The application of acidic fertilizer (particularly in autumn) using either a commercial "Camelia/Azalea" fertilizer, alfalfa pellets, slow-release pellets (3 months is best) well rotted vegetable scraps and/or the introduction of naturally acidic leaves, bark and pine needles will provide your Louisiana iris with a good growing medium. Mulching against the extremes of weather conditions will protect the rhizome. For this reason they are as happy growing in the steamy tropical gardens of far north Queensland in Australia or growing under snow in Washington State. Remember that Louisiana iris are the "teenage boys" of the iris world. So, if in doubt about anything, give them some more water or fertilizer! They will thank you for it. Louisiana iris have an interesting annual growth cycle and if you understand this and provide optimum conditions for your plants you will be rewarded with outstanding and healthy blooms in spring time. Louisiana iris will generally flower in mid to late Spring. The actual timing of flowering in their first year in a new location will depend upon when you purchased your plants, where you have planted them, what type of climate you enjoy and whether the particualar iris you have purchased or obtained are early, mid or late season blooming. Ensure that you provide adequate water to your plants prior to and while they are flowering. They need considerable water to develope and send up their magnificent blooming spike. Shortly after flowering has ceased you can cut off the flowering spikes at ground level. This will ensure that the plant keeps all of its efforts focused on growing rather than keeping unwanted seed pods developing. If you have done some hybridising and want to keep the seed pods, ensure that you stake the spike to keep the developing seed pod from touching the ground. You can also cover the seed pod to protect it from insect invasion. Pantihose "toes" are one good suggestion for use as they will expand with the growing seed pod, will dry out quickly after a shower of rain and are easily removed and discarded after use. During the hottest of the summer months most Louisiana iris will go into a form of semi-dormancy. If you keep adequate water to them during this time and ensure that their rhizomes are mulched you will find that they should maintain some foliage during the period. When the worst of the summer heat has passed you will notice that your Louisiana iris will start into their most active growth cycle. This usually starts when the soil temperature starts to cool down in early autumn. Once you notice the growth of new rhizomes you should start a fairly vigorous regime of fertilizing for the next six to either weeks. Don't be tempted to give your iris one big feed and leave it at that. You are much better off to give them a good feed quite often instead. Use the various fertilizers noted earlier in a two-weekly cycle. By late autumn the old summer leaf growth will start to wither and die off. You can carefully remove these spent leaves if you find them unattractive, but do so with extreme caution as the leaf spathe is more than likely protecting a new tiny plant down at the base. If you want to you can give your Louisiana iris a light feeding in late winter. A slow-release fertilizer is best at this time as it doesn't give the plant a sudden boost of nitrogen. In early spring the new bloom spikes will start to appear. It is quite usual for a clump to look normal one week and to show evidence of flowering spikes the next. The spikes can "sit" for several weeks and appear to do nothing at this time. It is the overnight temperatures which can have an overall effect on the actual bloom timing. A good indication of the rapid growth that your iris are experiencing can be seen in many of the leaves. They can have a crinkled "concertina" look to them and this is an indication of the warmth of the days accelerating the growth and the cool of the nights slowing it down again. This is a perfectly normal condition and will not adversely affect your plants in any way. Flowering spikes open in a succession of order. Some varities open their blossoms from the top of the spike to the bottom and others do it the other way. Both are acceptable and quite normal. Which ever direction your variety chooses to bloom in, you should expect each blossom to last at least two-three days. Each bud socket should have at least two blooms in it and each spike should have at least four bud socket placements. This will ensure a bloom sequence of several weeks from each flowering spike. Some colours have a tendency to fade in the intense ozone-depleted spring sunshine and this is an acceptable trait provided that the blossoms fade "nicely". Any blossoms which have their colour completely bleed and/or fade right out can be disappointing. On the other hand, the faded blossoms can add another interesting dimension to a blooming spike. Time and experience will teach you which are the most sun-fast colours and varities plus which which hybridisers have bred their iris to withstand colour fading. Some varities are known to re-bloom in autumn/winter. This is indeed an exciting prospect to be able to enjoy Louisiana iris blooms twice in one year. Most varieties which exhibit this trait bloom in autumn/winter with the same vigour as in the spring time but the colouration of the blossoms is often less vivid in the cooler months. Louisiana iris are also available in a range of heights. Before purchasing Louisiana iris make sure that you are aware of the eventual height (the height of the flowering spike) of the varieties you want as this can make a difference to their eventual placement in your garden. Once you understand and appreciate the unusual growth cycle of the Louisiana iris you will be assured of better bloom quality and quantity and healthy plants. The Society of Louisiana Iris (SLI) also has an active internet chat group (LAIRIS) where members share their experiences, knowledge and sense of humour with other folk from around the globe.
Heather Pryor
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