SELECTING A HOME for YOUR IRISES

(Note: These planting guidelines are for consideration to iris growers in the east and Midwest only.)

THE BEST PLACE TO PLANT YOUR IRISES

Imagine that every tree in your yard is now fully mature. Look upward and make certain that no tree limbs are or will become closer than 10 feet from the edge of your planting area. Tree roots will extend from that tree an equal distance and your wonderful soil we eventually be ruined. Avoid shade as irises are sun lovers. Full sun make them the happiest!

Survey the lay of the land. Spot areas with higher elevation. Excellent drainage is an essential requirement of irises! Good soil grows lush weeds with large leaf surfaces and dark green grasses. Some gravel is not a bad thing as it improves drainage, but boulders are very bad. Clay soils are a godsend as they retain moisture and trap organic matter and fertilizers.. Sandy soils offer excellent drainage—a disaster in drought conditions.

Avoid slopes. Soils will wash against the foliage and bury the rhizomes—a deadly invitation to bacterial infections.

IMPROVING YOUR SOIL

Whatever soil you have on your property contains unknown qualities but you can bet it exists there for many good reasons. Quality soil amendments can be cultivated and fluffed into your native soil but too much of a good thing encourages erosion. Bury them underneath your native soil then recover. Your plants will get full use of the materials quickly and for a longer period of time.

Get a soil test before you begin to think about planting. The local farmers coop provides soil containers and will explain to you how to gather soil for their lab tests. Be sure to request recommendations to create a soil with a pH of 7.0 and that you are planting bearded irises.

OTHER RECCOMENDATIONS

Manures are a breeding ground for grubs that feed the tunneling moles (carnivores) whose tunnels provide an underground pathway for voles (herbivores) who eat iris plants and rhizomes. Rotting leaves are delicious and alfalfa products in small quantities are amazing and expensive!! I love manures but they have tons of weed seeds.

Chemical fertilizers should always be buried under your plants. Topical applications of potassium and phosphate scratched into the soil is time wasted as they are washed away with heavy rains. Nitrogen moves only vertically but pellets that wash against and onto your plants during rainfall may burn and damage plant tissues.

It is desirable to prepare your soil in the autumn prior to planting. Late summer/early autumn cover crops yield amazing results and can be “plowed under” before winter so that your planting areas can settle during the winter. I highly recommend mounding the soil 12” higher than ground level or create 12” planting ridges or mounds which will easily settle to 6” in height come spring.

PLANTING PROCEDURES

Plant your irises on raised mounds or ridges. It is very important that you firm the soil under the rhizomes as you plant. In the south (before winter), check to be sure the top half of the rhizome's surface is above ground (crawdad style).

If you intend to leave the bed undisturbed for 3 years, plant your single rhizomes 36”apart. Quality varieties will produce perfectly happy clumps! Plant them closer and you will have an iris jungle!

Water heavily when planting—very heavily! In future watering, keep the foliage dry as possible. Drip tapes or soaker hoses will do the job!

WEEDING and MAINTENANCE

Care for your irises like you would your vegetable garden. Grass and weeds are never welcome. I suggest that you capture (kidnap) a skilled gardener who loves to weed, making certain that he/she is wealthy and generous. Spend some extra bucks to install security fences to prevent any possibility of escape!

Associate with friends who can provide access to an experienced hoe-er. Every beautiful garden has benefited from the services of a good hoe-er.

Never be without vinyl-coated fabric gloves. They protect from hand punctures, scrapes and broken fingernails.

Buy at least a half-dozen one gallon garden sprayers when they are on sale. Label each container with a permanent marker including the name of the chemical you are using, it specific purpose and exacting directions for mixing! Use this sprayer ONLY for this mixture.

Find two wide-brimmed straw hats in late winter and early spring before the good ones are sold! I can assure you that spring winds can blow that hat into another state. In the blink of an eye it may fly off your noggin and under your lawn mower It is an inexpensive way to avoid skin cancer and premature wrinkles around your eyes.

Mulching helps retain moisture in the soil and keep down unwanted vegetation. Make certain that you do not place mulch on top of the rhizomes!

Weeding is a science of order and discipline. When heavy rains appear anticipate a massive germination of weed and grass seeds. In order to keep your unwanted vegetation under control, you need a plan of attack! Select three categories of grass and weeds that need to be removed first.

Recognize and identify those that are the most persistent (the most difficult to destroy and keep in check), the most aggressive (grasses!), and the toughest to eliminate (those with tap roots, and creeping rhizomes). When making your first trip through the garden, get these evil demons first! You will finish round #1 with a sense of great accomplishment and the entire task won't seem so impossible! Round #2 go for the big ugly ones before they become too established to pull easily. Round #3 will leave the little oxalis and short-lived plants that will do the least harm to your iris plants. In many cases, these little fellas will already be yellowing and preparing for their disappearance!

DISEASES, PESTS and UNWELCOME GUESTS

I never remember a time that there were no moles in our yards. I have already mentioned that they are responsible for the destructive voles. I kill grubs. They are evil. You have read my spin above on the grubs/moles/voles. Discover Imidicloprid insecticidefirst marketed as Merit. It must be applied here in the month of October in order to kill all those baby grubs! We do not have the iris borer in Tennessee, but Imidicloprid is also a great weapon to eradicate the iris borer that haunts gardens north of us.

Fire ants have finally made the journey north into Tennessee. They won't hurt an iris but they can bury a plant under a mounded sculpture of soil. I have destroyed mounds that had buried iris plants after the stinging villains have abandoned their hut, but the iris plants started growing immediately and bloomed the following spring. You can gently disturb a fire ant mound and they will break up housekeeping, reproduce and build other mounds (plural) nearby!

If grass is out of control, discover Sethoxydin contact herbicide. It is still available in pint containers marketed as Vantage contact herbicide. Young grass dies in days; older grasses may require re-application.

Broad-leaf weeds? Clopyralid contact herbicide (introduced under the name 'Stinger') is an effective option. Again...small plants die quickly. Overgrown weeds? I don't dare add more chemical to the sprayer! Summons your hoe-er!

Leaf spot or crown rot? Try chemical-free Consan Triple Action fungicide and algicide. It is chemical-free and is a detergent invented and first marketed to the restaurant industry to clean cutting surfaces, walls, floors and dirty vegetables.

Chant after me: “No chemicals! No chemicals!”

24-D brush killer? Don't you dare. It is a product of Satan.

PURCHASING NEW VARIETIES

When we are new to irises, all varieties seem wonderful. Sadly, there are multitudes of long-time iris devotees who never learn differently. Here are an even dozen tips to help you purchase quality iris plants for your garden.

-Avoid varieties over 36” tall. They are not wind-proof or rain-proof.

-Early bloomers are often victims of late freezes.

-Flowers with wide hafts and petals project more color in the garden.

-Stalks that open one bloom at a time remain in bloom three times longer than those that open 3 blooms at once!

-New introductions often have lengthy, flattering descriptions. If there is no mention of bud count, branching, haft width, vigor, etc., there is an excellent chance that the variety is lacking in these qualities.

-Parentage of a new variety is often a clue to a plant's behavior and habits.

-Some iris breeders exaggerate.

-Some iris breeders see no faults in their “children”. (A type of blindness??)

-A plant that is overly vigorous is as problematic in the garden as one that sulks.

-A plant that does not bloom each year is no bargain.

-A plant with erratic growth and/or disease susceptibility is trash.

-An iris that wins an American Iris Society award may not be a good garden iris.

Some years ago at an AIS convention during judges training, a debate ensued concerning inferior varieties winning major awards. Famous hybridizer, Ben Hager from Stockton, California asked to be recognized. His comments were brief:

“There are many irises that should be introduced, but AIS judges need to learn that only top quality introductions should be presented an award!”

Sadly, some very important things do not change.

Something Smells Rotten!

“Soft rot” attacks many plants and tall bearded iris are no exception!  It can attack anytime when days are warm and it is much more prevalent in humid climates in the east and Midwest.  Soft rot is a disease caused by Erwinia carotovora, a bacterial phytopathogen.  Erwinia carotovora is widespread in occurrence and there are many strains.  

Iris growers in the west and southwest have to cover their rhizomes to prevent sun scorch. In the snow belt they cover their rhizomes for protection from the cold!  In the temperature extremes and moisture in the southeast, this would never work unless you are planting in sand.  Being a native and life-long resident of Tennessee, we do things a bit differently.   

When is it most likely to strike?
    
1.) Be alert when the daytime temperature is (say … 80 degrees) and the
relative humidity is (say .. 70%).  I have coined a red-neck term I refer to as “humiditure”.  When the humiditure exceeds 150 (70% + 80 degrees), be on the alert! Monitor the combination of heat and moisture. 
2.) Tall Bearded iris need lots of sunlight to bake the top of the rhizomes and the foliage. Clumps growing too close to each to each other greatly compromises this serious need of  the bearded iris plant. Best spring bloom typically follows a miserable, scorching hot summer.  Bearded iris are original natives of the scorching Middle East!  Planting your irises in shade will reduce their vigor and bloom production.
3.) Air circulation is another requirement for your iris to remain free of this pesky bacterial infection.  Poor spacing between iris clumps is an open invitation for big trouble in an iris planting.
4.) Iris rhizomes planted too deeply are the #1 cause of this infection here. In the southeast, the upper half of the rhizome needs to grow exposed to the elements. (One of the best iris growers I ever knew in this area said to plant them to look like “crawdads”!)  
5.) Planting on slopes can be deadly. When soil washes up against the back of the rhizome where the foliage attaches OR covers the rhizome, you can expect problems. A rain shower followed by blazing sun with soil smothering the rhizome will cook the leaf bases and rhizomes. You may be clueless until the leaves start collapsing and the stench of soft rot is evident.  and encourage soft rot.  Excellent drainage is essential! 

All soils contain this bacteria. You can sterilize your soil but it is a matter of months before it re-establishes itself in your soil!  Be ever watchful as immediate treatment will be the most successful approach.

Diluting the bacteria will also play a giant role in eradicating the infection in your garden.  If soft rot is detected, it is imperative to physically remove all infected leaf and root tissues—scraping away the decayed portion of the rhizome and leaving it fully exposed. 

Treatment for bacterial infections of patients in medical facilities typically includes immediate fluid infusions.  That being said, you can use a very narrow stream  using a high-pressure nozzle on a garden hose and “power wash” away the rotten tissue, being careful to not splatter and spread this infection to neighboring plants. Diluting this bacteria sufficiently will result in its instant death.

Whether you scrape or wash away the infected tissue, be certain that only VERY solid tissue remains.  Drench with a bacterial fungicide labeled for the bacteria (see paragraph #1) . (I define “drenching” as having coated every leaf and rhizome in the clump. ) 

I use Consan Triple Action that is now available in most garden centers—2 Tablespoon in a one gallon sprayer.  I have used it successfully for the past 15 years.  It is a detergent developed for the restaurant industry to wash cutting tables, walls and floors of restaurant kitchens. It smells wonderful (there are no chemicals) and it will not harm you in any way.  If you use more than the prescribed amount, you will find your iris plants covered in suds.  Why waste this wonderful compound when just a little will do the trick??!!

Too many beautiful new plantings completed in soft, silky soil will often produce beautiful, lush growth.  These same iris plants are often decimated by soft rot come spring when the unsettled, fluffy soil has settled around and over your rhizomes, burying your iris plants.  These same well grown and gorgeous plants will produce magnificently IF ONLY the gardener will wait until the soil was well settled before planting.

Prepare your planting areas in advance. Have your soil tested!

The late Alan Ensminger of Lincoln, Nebraska advised that you cultivate your new soil in early spring, plow in a generous amount of balanced fertilizer and sow rye or another grain crop.  Do NOT let it go to seed, but plow it under as a soil conditioner.  You are ready to plan for planting the following spring and summer.

I would suggest that you build your elevated bed at least 12” high because the soil will settle to at least half that height by spring.  Extreme fertility can cause lush growth that is an invitation for soft rot.  By following Mr. Ensminger's advice, your soil will be well regulated for planting when your new irises arrive. 
 

Iris Culture Tips

I planted my first named tall bearded iris in 1962 so the learning process began some 55 years ago.  Keep in mind that growing bearded iris in the eastern United States is in many ways a totally different experience than on the west coast where the majority of tall bearded irises are produced today. 

Bearded irises were first discovered in desert Middle East so keep this important fact in mind when making gardening decisions. 

We get much rain here in the southeast and subsoil saturation is a common occurrence.  The most important preventive measure is to plant your iris on an elevated ridge or mound of at least 12 inches.  By bloom season the ridge will have settled to at least half its original height. This extra effort at planting time will be of great value in the iris garden. We have our soil tested and any fertilizer needed or organic matter that we choose is placed at garden soil level under the 12” ridges. 

Here we plant our iris rhizomes exposed to the sun, rain and wind. In colder climates and those with scorching sunshine, the rhizomes need to be protected by a layer of soil over them.  

Once the iris bug bites, new gardeners often order truckloads of advertised “topsoil”.  (Where does one find “topsoil”?) Isuggest that you plant your first iris in the soil that exists on your property. Adding organic matter is always helpful, but if you choose that route, an ideal situation is to plant a cover crop the first summer, fertilize your cover crop with nitrogen for optimum growth (which leaches down into the soil quickly), thendeeply cultivate before planting the following summer.  Your soil should then be in ideal planting condition! 

Sprinkling commercial fertilizers on top of an iris bed is a waste of energy and money as the first rain will wash it away; even worse, it can wash into the plants and cause rhizome and foliage damage.  Whatever fertilizer you choose, work it deeply into the soil so the roots can feed on it.

Irises will not grow and bloom well in shade.  You will discover that the hotter and more miserable the scorching summer sun bakes your irisplantings the heavier your spring bloom will be.  In the eastern U. S. constant watering in summer heat is risky but in serious drought will be beneficial.  Do NOT water overhead until AFTER the sun sets and the temperatures drop below 80 degrees.

Irises like to be free of weeds and grass with plenty of sunshine and air circulation. .  Hand weeding is best.  Today herbicides are in wide usage, but keep in mind that in the moist, humid southeast, these chemicals dissipate slowly, particularly in heavier soils. Isuccessfully “spot spray” stubborn grass seedlings with a contact herbicide, being care to prevent drift as much as possible.   You should also consider alternating/rotating pre-emergent type chemical herbicides, choosing those that target your most insistent weed and grass species at the time of treatment.  A common error is excessive and too-frequent over-application which can play havoc with your soil and reduce plant growth—both rate of increase, width and height of iris foliage and size of iris rhizomes.  Chemical contamination is a certain death to good soil!

The addition of organic matter is a positive plan.  Aged manures provide exceptional accelerated growth AND weed seed aplenty.  Covering loads of manure with a tarp for 8-12 months before application heat-kills many of the   seed.  Oat straw is a superb soil conditioner—much preferred over wheat straw. There are other good choices, but commercially bagged soil additivescan be expensive and ineffective. Good organic matter will break down quickly and provide positive soil aeration.  Most recommendations include “side dressing” with a commercial fertilizer 6-8 weeks before bloom.  It is rarely dry enough to cultivate and incorporate chemical fertilizers intoour soil in February and early March. I would remind you again that fertilizers spread on soil surfaces is a foolish waste of time and money.

Rotating your planting areas is ideal as iris are heavy feeders.  Few own the acreage required for such rotation on a massive scale.  Most of us have other life experiences outside our gardens.  Learn which soil treatments and gardening habits yield the most success with your irises. Growing plants is not rocket science, but it does require dedication and constant observation to see which techniques give the best results.

If you want good first year bloom on your irises, seriously consider transplanting at the end of your bloom season in the southeast. There is a natural recovery/rejuvenation process in bearded irises that begins at the end of their exhaustive bloom season.  Begin cultivating in fertilizers and organic matter 6 weeks after bloom to give your irises a jump-start on next spring's bloom.     

Feel free to email us if you have a plant problem. There are occasional problems that require proper chemicals to eradicate a specific problem.

We can hopefully help you find a solution.  Most important is learning to enjoy the Vitamin D dosage from the sunshine while caring for your plants.  

The Barbara Nicodemus Garden

My favorite indulgence as an iris judge is to visit a hybridizer’s garden and walk the seedling rows.  This was my second visit to this wonderful iris garden in western Missouri and due to problems at my day job, it was the only out of state trip of the spring bloom season this year.  A trip to Barbara’s wonderful garden is never a disappointment.

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Chuck and I went through the horrendous job of transplanting in late August and September.  It seems like all our beds came due to be divided at the same time. Chuck prefers to dig up the entire clump after the second year of bloom.   

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New parents, like new members of an iris club, are often excited  about their latest life choices.    The  “been there, done that” group of  both sectors might be a bit less excited about what lies ahead than those on their first go around.   New member(s) are often smothered with as much information as expectant parents ... and some of it is as worthless as a hoe without a handle.    

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The beginning of my personal foray into selling irises was the result of no available expendable income.  If I were to continue this hobby, I needed cash!  Even the most elementary understanding of morality would demand that monies sorely needed for food, shelter and clothing of the family not be improperly spent on flowers of frivolity!      

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Don’t you just HATE those iris varieties that grow “like weeds”?!!  It seems that they are forever needing transplanting.  If you transplant every other year (all that work!) you only get really good bloom once every two years.  Not fair!

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