Monday, September 23, 2019

Importing Iris into Australia

By Mel Schiller

Bailey and I at Smokin Heights are in the process of going through what is considered the best protocol and procedures of importing bearded iris to Australia from the United States.

As we type this, we have approximately 90 rhizomes coming into an Australian Quarantine Facility in Melbourne from the United States Of America.

It is an extremely lengthy and costly exercise. Here is a basic overview:

Before we even decide on what rhizomes we would like to import into Australia we need to apply for a permit to import conditionally non-prohibited good: plant and plant products, essentially Iris Spp.

To obtain the permit is probably the easiest step in the process!

Once we know that we have obtained the permit, we then look at which rhizomes we would like to import. Bailey and I agree to disagree on this process, bearing in mind the purchase price, the shipping, the phytosanitary certificate and the forever changing currency!
Our permit has a 12 month use on it. We use the permit once in a year. It is best to have the irises come into Australia at the beginning of spring after the USA bloom time to slowly acclimatize to our heat and weather conditions.

Before being mailed to Australia, the rhizomes are dug, labelled, washed and trimmed then sprayed to remove pests and eggs. A health inspector's visit is organized to issue a phytosanitary certificate to approve of the mailing of the iris rhizomes into Australia. This certificate approves the treatment of the rhizomes being shipped to a foreign country and says that all permit conditions have been met.

The rhizomes are inspected upon arrival into Australia by Biosecurity and held in customs. This process takes a long time. All imported goods must be free from contamination including no dirt, no insects, no living creatures in or on the rhizomes and packaging. The packaging must meet Australian regulations. The package and rhizomes must be appropriately labelled and packaged in accordance with the import permit conditions.  If these conditions are not met, the rhizomes may face destruction, export, or even forfeited to the Commonwealth at the importer’s expense.

Once the rhizome pass this stage, they are then fumigated by a company. The fumigation is the worst stage for the iris. Some rhizomes can handle the process; some do not. The rhizomes are fumigated with Methyl Bromide 32g/m3 for 3 hours at 21 degrees Celsius, at the cost to the importer.

Once this process is completed the rhizomes are taken privately to a Quarantine post entry facility where they can remain for a minimum of 3 months, or until sufficient new growth has occurred to enable them to be screened for any disease symptoms.  The facility schedule of fees are per pot. The rhizomes are screened for any symptoms twice or three times over the 3 month period at the cost to the importer. The rhizomes are not classed as single items. They are classed as the whole shipment. The shipment of rhizome have to be free from disease and be cleared by a biosecurity officer before they can be released. Fees need to be paid to the Quarantine facility and Biosecurity before the are released.

Rhizome collected from Quarantine
Once we have been notified that the rhizomes have passed the inspections and have been released, we arrange for transportation from Melbourne to our home in South Australia.

Australia has extremely strict laws on importing goods and plants. We have a very unique environment and agriculture industries and want to minimize the risk of pests and diseases entering into the country.

On top of that, there are also strict laws moving plants foods and animals from state to state. We cherish our uniqueness and don’t want to damage it for future generations. Plant pests and diseases can significantly damage Australia’s productive plant industries. They reduce yields, lower the quality of food, increase production costs, and make it difficult to sell our produce in international markets.
Plant pests and diseases may also be a huge threat to our natural environment: native forests, grasslands, and shrub lands.
Australia does not need the iris borer caterpillar (Macronoctua onusta), which are the most destructive insect pests of iris.
  • The caterpillars chew holes into the leaves and tunnel all the way into the rhizome.
  • The tips of iris leaves turn brown and seem to be dying, but the entire plant dies very rarely.
  • Iris borers cause severe damage to irises by feeding on the rhizome.
  • Management of iris borers is difficult, but damage caused by them can be reduced.
  • Pesticides or natural enemies of iris borers may be used to control these insects.
Again, Australia is lucky to be free of many damaging pests prevalent elsewhere in the world. 
Fewer pest and disease problems mean lower production costs. Areas where rigorous biosecurity can deliver “pest freedom” give Australian producers an enormous advantage in international markets and allow us to have safer and cheaper locally produced food.
Please do not ship plants to Australia without following our strict guidelines. For those Australians who bring plants in without the proper paperwork and procedures, well I know what I would like to say: you're a bloody idiot!

Monday, September 16, 2019

Three Myths About Bearded Irises

by Tom Waters

Every area of human knowledge has its myths: ideas firmly believed by large numbers of people that are not actually true. The rise of the internet and social media has further complicated the process of separating myth from reality. In earlier times, a curious person might seek out a book or an expert to resolve a question, and stand a fair chance of getting accurate information in return for their effort. But today, when a curious person does an internet search instead, the information they find is just as likely to be wrong as it is to be right.

On the subject of growing bearded irises, I have found three myths that seem to be ubiquitous, and inevitably resurface during any internet discussion of the subject. This article addresses each of these three myths, in the hope that a clear exposition of each will provide a little island of solid information that is often missing from untethered internet exchanges.

Myth #1: Bearded irises will not bloom unless the tops of their rhizomes are exposed to sunlight

Although, as I shall explain in a bit, there are some good reasons for planting irises with the tops of the rhizomes exposed, it is not necessary to do so to ensure bloom. Irises bloom just fine if planted with an inch or more of soil over the rhizome. Nothing magical happens when sunlight strikes the surface of an exposed rhizome.

Where did this myth come from? I think it has three sources. The first is a very basic piece of advice: iris rhizomes are not bulbs. Most spring-flowering bulbs (daffodils, tulips, crocuses, etc.) need to be planted fairly deeply (three times their height is a common recommendation). If you plant an iris as deep as a tulip, it may indeed not bloom. In fact it may not survive at all. The second is a general remark about growing conditions irises prefer: they like full sun, or at least half a day of sun, and will not bloom well in too much shade. Finally, there is a bit of traditional advice that irises should be planted "like a duck in the water", with the top half of the rhizome above the soil surface. In think these last two points (a recommendation for planting with exposed rhizomes and the fact that irises bloom best in sunny locations) led people to blend these two ideas together and conclude that it is sunlight striking the tops of the rhizomes that causes irises to bloom. The advice not to plant them deep like tulips or daffodils then reinforces this notion.

Okay, if it is not necessary to expose the rhizomes to direct sunlight to ensure bloom, should I plant them exposed or covered? What is the best planting depth?

The short answer is that it just doesn't matter very much. In most gardens, irises with the rhizomes exposed and irises covered with a half inch or inch of soil will both do equally well. If you look at an established clump, you will see that the rhizomes themselves sometimes grow down into the soil and sometimes grow up onto the surface. It's all good.

In some locales, particular climate conditions can favor either shallow or deep planting. In a climate that is often rainy and humid, exposed rhizomes are less likely to rot from wet soil. Much of our traditional gardening advice comes from places with such climates: the UK and the eastern seaboard of the US. I believe the advice to plant with rhizomes exposed originated in these areas, and then was simply repeated.

In areas with very cold winters, Irises may benefit from being planted more deeply, making them less susceptible to heaving during freeze-thaw cycles.

In dry, hot regions (such as much of the western US), planting with the rhizomes covered offers some protection against sun-scalding and desiccation from heat and wind. The rhizomes appreciate being below the soil surface, where conditions are a little cooler and moister.

Bottom line: Plant covered or uncovered, according to your preference, experience, and local advice. Irises will bloom just fine either way.

Myth #2: Irises can "revert" to some other color

It seems like everyone has heard a story of a beautiful clump of irises, say nice ruffled pinks, "reverting" to white or purple after a few years. In fact, this does not happen. Irises do not spontaneously change color. (There is one minor qualification to this statement, which I will address below.)

No, this iris will never "revert to purple"

Where does this myth come from? One source, I think, is that some plants do appear behave this way, particularly annuals that reseed each year. If one plants a hybrid zinnia or morning glory, for example, the plants that come up from their seed in future years will not look like the original, and in fact may show simple "wild type" colors common in the original species from which the hybrid was developed. A second source of this myth comes from the fact that if different irises are planted together, one of them may multiply faster and eventually take over the planting, making it seem to the casual observer that the irises in the planting have "changed" from the color that was originally common in the planting to the one that eventually took over. But note carefully that this is competition between two different plants, not a single plant changing color.

In almost all cases where people say their irises have "changed color" or "reverted", this is the explanation: there was more than one variety in the planting to begin with, and one that had not bloomed the first year or two grew well and came to dominate the planting in later years.

It is possible for the coloring of an iris to appear somewhat different from one year to the next, because of weather differences or chemical exposure. The blue and violet pigments, in particular, are somewhat sensitive to unusual weather. These changes are changes in the darkness or saturation of color, though, and cannot result in a whole new color or pattern. A pale blue iris may appear to be cool white in one year or sky blue in another year, for example, but will never become yellow or pink. Some herbicides cause deformed blooms with color strongly depleted in some parts of the petals, but the deformity is obvious.

There are a couple other ways an iris of a different color can appear in a planting, even if only one variety was planted to begin with.

The first is hybridization. Just as your morning glories may reseed themselves, so a bearded iris may occasionally form a seed pod and drop its seeds into the soil around the plant. If these seeds sprout, the seedlings may well be a different color than the parent, and when they bloom (perhaps three years after the seeds are first produced), the gardener may be in for a surprise! To prevent this from happening, you can remove the bloom stalks after the flowers fade, so that seed pods do not develop.

Although possible, seedlings appearing in a bearded iris clump this way seldom happens. Most bearded irises do not produce seed on their own. (In my garden, I see maybe two spontaneous seed pods for every thousand blooms.) And bearded iris seeds don't germinate well in many climates without special attention. If seedlings do sprout in an established clump, they will likely be crowded out by the parent. Hybridizers go to a great deal of trouble to get bearded irises to cross-pollinate and to grow the seeds to maturity. The process can and does happen without human intervention, but only seldom. (If you grow beardless irises like Siberians, the appearance of unexpected seedlings is much more likely.)

Finally, an iris may experience a mutation that causes the flower color to change. Such mutations, called "sports", are extremely rare events. Except for a few historic varieties that are prone to such mutations, most irises will never produce a sport. You can grow a thousand different varieties for a decade and never see one. I started growing irises in the 1970s, and have never seen a sport in my garden, or in the gardens of any of my iris-growing friends.

Bottom line: Bearded irises do not spontaneously change color. Each iris is a unique individual, and will retain its original color and pattern forever. If you see a different colored iris in a planting, it must be a different variety that was already there and just had not bloomed, or had not been noticed, before.

Myth #3: Iris foliage should be trimmed back in the fall

It's a ritual that some gardeners swear by: attacking their iris beds in August or September with shears, resulting in a defoliated war zone that looks as though someone had come through the garden with a lawn mower set at 8 inches. Sadly, those irises are now deprived of much of their food source: photosynthesis in green leaves.

Why do people do this? What makes them think that cutting leaves in half is good for their plants? I think there are two sources for this myth. The first is that many perennials do benefit from being cut back at certain times of year, to stimulate new growth, and a new flush of bloom in some cases. But if you are an observant gardener, you will notice that the anatomy of these plants is different from that of irises. These plants have buds along their stems. Removing the tops of the stems encourages the lower buds to grow, resulting in bushier, more vigorous plants. But irises do not grow this way. All the leaves of a fan emerge from a single bud at the tip of the rhizome. When you trim a fan back, you are just chopping leaves in half, not removing any upper buds to stimulate lower buds into new growth.

The second source of this myth is that when irises are dug and divided, the fan is traditionally trimmed back. This is how irises are generally sold: bare-root, with roots and fan trimmed back to about 6 or 8 inches. This trimming is a good idea for an iris that has been dug and divided. Its growth has been interrupted, and it will take some time for new growth to emerge from the rhizome. During that time, a big fan of leaves can weaken the plant by drawing too much water and energy from the rhizome. The leaves lose water by transpiration, which the old damaged roots are not able to replenish. A big fan also makes it easy for the newly planted iris to topple over or become uprooted. But these reasons only apply to plants that have been dug and divided; they are not applicable at all to plants left growing in the soil, undisturbed.

Some have said that trimming back in the fall helps discourage iris borers, which lay their eggs in the leaves at this time of year. The eggs, however, overwinter in dead, dry leaves, not growing green leaves. Removing dead foliage is helpful; cutting green leaves in half is not. The recommended procedure for borer control is to remove all dead foliage and burn it in late winter or early spring.

Some just think the trimmed fans look tidier. This is understandable. By the end of summer, iris foliage often looks pretty tired and unattractive. Many leaves are drying at the tips, getting a little pale and floppy, and perhaps suffering from damage from insects or other ailments. Ironically, if you trim the leaves back, then the tops where you cut them will just turn brown and dry up, so instead of tall leaves with dry ends, you have short leaves with dry ends. Was it really worth it?

Bottom line: Cutting through the green fans of an iris in the fall does not help the plant, and may weaken it slightly, as you are reducing its capacity for food production through photosynthesis. Irises are rugged, and this slight weakening is something most of them can cope with without suffering much, but why put them through it at all? It does "tidy" your garden, but that only benefits the aesthetic sensibilities of the gardener. It does not help the irises in any way. If you want to tidy up at this time of year, restrict your activity to removing dead foliage and dry leaf ends. Don't cut green leaves!
The foliage on the undisturbed clump on the left should not be trimmed. If you want to tidy up, remove just the dead leaves (1 and 2) and the dry end of leaf 3.

Monday, September 9, 2019

Stalwart Pacifica Iris for the Garden

Kathleen Sayce, September 6, 2019

Returning to a topic of perennial interest among PCI growers, the following discusses those durable, enduring species selections and putative hybrids that often grow for decades in gardens, surviving neglect, weather vagaries and thriving year after year. These are notable for their endurance in many gardens along the West Coast. With climate vagaries on the rise, these may persist while more recent hybrids vanish.  As you will see, PCI 'Canyon Snow' is a major contributor to durability. 

Debby Cole and Bob Sussman shared names and photos of recent hybrids that show good vigor. Several photos were downloaded from the AIS Iris Encyclopedia.

Photo by John Weiler, AIS Iris Encyclopedia

PCI ‘Canyon Orchid’ ('Canyon Snow' x (I. douglasiana sdlg. x Abell I. munzii sdlg.)) X Lenz purple I. munzii sdlg., 1985 Dolores Denney

Photo by Kathleen Sayce

PCI ‘Canyon Snow’, (I. douglasiana x unknown), 1975. Dara Emory, Santa Barbara Botanic Garden:  this tough PCI survived weeks out of soil when a local gardener passed plants to me two weeks after digging up the clump. This hybrid also contributes to several more PCI known to endure garden conditions well. 

Photo by Kathleen Sayce

PCI Cape Sebastian, an I douglasiana selection, not registered, from Siskiyou Rare Plant Nursery:  For every passion there is a trigger event, and seeing this PCI in flower in my garden for the first time was that trigger for Pacifica Iris. 

Photo by Kathleen Sayce
PCI ‘Clarice Richards’, (Stambach red sdlg. X McCaskill 72-60), 1983, Richard Richards: Richard developed several very tough PCI, selecting for plants tolerant of hot dry growing conditions at elevation, east of the Los Angeles basin in southern California. It may be that tough under hot/dry conditions is also tough under cold/wet conditions in the Pacific Northwest. 

Photo by Kathleen Sayce

PCI ‘Harland Hand’ 1989, D. Lennette:  Has thrived in my garden for more than a decade. 

Photo source lost, someone please remind me!

PCI ‘Native Warrior’, 1970 Phillips:  If you are looking for red genes, this might be a PCI to use.

Hybrids from Joseph Ghio, Bay View Gardens, Santa Cruz, California have endured for several decades along the West Coast. Many of his hybrids tend to flower too early to set seed reliably in the Pacific Northwest, but these three are sturdy and return year after year. 

Photo by Kathleen Sayce

PCI ‘Big Money’, 1982 Ghio: the only aspect of growing frilly yellows that I do not like is the petals melt in the rain. Otherwise, if late April-early May is dry, PCI 'Big Money' is gorgeous.

Photo by Richard Richards, from AIS Iris Encyclopedia

PCI ‘Los Gatos’, 1974 Ghio

Photo by Kathleen Sayce

PCI ‘Mission Santa Cruz’, 1982 Ghio:  One of my very first PCI, and still outstanding each spring in the garden. Also a great source of genes for future hybrids. I'd like to do wide species crosses with this as one parent, with Siberian group species.  

From Debbie Cole, Mercer Island, Washington, west of the Cascades and just east of Puget Sound; Puget Sound gets half the rain of the ocean coast, with colder winters and drier summers. 

Photo by Debby Cole

PCI ‘Brevette’, 2018:  new from Debby Cole, this hybrid is showing signs of good durability, though it's a very recent registration. 

Photo by Debbie Cole

PCI ‘Egocentric’, 2007: this PCI shimmers with pink in the garden on a gray day. For those who live in cloudy areas, it's marvelous at brightening up the garden.
Photo by Mike Unser, from AIS Iris Encyclopedia

PCI 'Periwinkle Persian', 2004, D. Cole, also shimmers, but in a cool and calming way. 

From Bob Sussman, Matilija Nursery, southern California, come three tough PCI that cope with soCal’s mineral heavy water and long, hot dry summers. As with Richard Richards' hybrids, these seem to do well in the Pacific Northwest. 

Photo by Bob Sussman

PCI 'Canyon Banner' (‘Canyon Snow' x 'Valley Banner’), 2019:  Parent PCI 'Valley Banner' is also a durable garden iris, though more difficult to find these days than during the late 20th century. 

Photo by Bob Sussman

PCI 'Chocolate Parfait' (’Pacific Rim' x 'Garden Delight’), 2019

Photo by Bob Sussman

PCI 'Dr. Richie' -('Canyon Snow' x I. douglasiana x Cio-red seedling), 2019

Looking for vigorous PCI genes for hybridizing?

Iris douglasiana seedlings of garden heritage tend to be more durable than other PCI hybrids. Flowers are species-like in color and form, foliage varies from low to tall, and from light green to very dark green. Some selections have outstanding dark evergreen foliage. 

Two of my oldest PCI are I. douglasiana ex garden plants, one is an outstanding pass-along plant from an elderly friend who had gotten her starter clump from another gardener, and grew it for decades before giving a clump to me. The second is a low growing selection with lavender flowers. A few years ago, I received another selection, from coastal SW Oregon, with outstanding dark green foliage and lavender flowers; this plant is worth growing for the foliage alone. 

Several PCI species may persist in gardens longer than hybrids, if base soil is acidic and well drained. Some of my Iris tenax plants are more than fifteen years old, and thrive on a slope in afternoon sun each summer, and flower every year. On the other hand, Iris innominata from seed has dwindled and no longer flowers; I may have to move my plants to sunnier locations. 

Iris munzii, I. hartwegii, and other Californian species of limited natural range may be too fussy to grow in ‘strange’ soils. I moved I. hartwegii australis (seed grown, from a private garden) from sandy soil to a planter two years ago; while the plant has thrived, it has yet to flower. An I. douglasiana X I. chrysophylla hybrid thrives for me, but again, it is probably the I. douglasiana genes doing the thriving. 

Enjoy the flowers. Study the geography of their gardens of origin. This may help you find a PCI that thrives, and endures, in your garden for decades to come. 

Monday, September 2, 2019

On the Road Again: The Miller Garden, Canby

By Bryce Williamson

Those of you who read The World of Irises on a regular basis know that I am a firm believer in garden visits. Yes, I know we have gotten older and in my case slower, but visiting gardens is so important in a time of high prices for newer irises. By visiting gardens, I find the irises that I like and irises that are growing well as garden plants.

The season’s On the Road Again posts will be about Oregon and Washington and I am going to cheat, combining information in the post about the gardens and what I saw in the last two years.

Flying into Portland from San Jose (who would have thought at 6:30 AM flight would be full?) I picked up the car and headed first to Lynda and Roger Miller’s garden in Canby. I had written Lynda that I was coming up and she wisely told me not to take the freeway to the connection to I-5 and instead drop down on the Old Portland Highway and it was perfect—traffic flowed smoothly and I cut at least a half hour off my time.

Lynda and Roger have put down new roots in Oregon after their move from the Midwest. And the garden is a joy not just for the irises, but all the other plant materials integrated into landscape. They also sell a wide variety of perennials and conifers. 

Lynda Miller
Lynda has seedlings in all classes of bearded irises ranging from dwarfs to tall bearded. Lynda is well known as a successful hybridizer of both diploid and tetraploid miniature tall bearded irises. Her ‘Moose Tracks’ is gathering lots of votes from AIS judges.

'Bingo Marker'
Miller 13918
Miller 4118-B
Lynda also has some fine tall bearded irises. Her 'Football Hero' was the top Award of Merit winner on this years AIS awards list. 

'Football Hero'
Among her irises, I liked the following.

'Amazon Queen' has a huge flower and it is not a flashy color, but I am planning to add it to the collection next year because I believe it is one of those varieties that will grow on me as I see it from day to day.

'Amazon Queen'

A personal favorite of mine is her 'Ninja Warrior'. When I heard the color combination of rose-pink standards and black falls, I thought, "This cannot work." But it does.

I like and hybridize pink plicatas, so I really like her 'Blushing Grapes' with its pink ground; many of the other Region 13 hybridizers are working on orange grounds, but I think pink compliments the plicata edging. This is another iris on the want list for 2020.

Lynda is also working with space age irises. She is keenly aware of the potential faults of this popular class of irises and working to create flowers that do not have those faults.

'Love in the Air'
Miller 1716B
Miller 4817C

Miller 5918
'Cookie Crisp'
As one might expect in Region 13, Lynda grows many new things from hybridizers. Here are a few things that have impressed me the last few years.

'Dancing Days' (Keppel)
Strangely, we do not have a lot of good reds these days, but Terry Aitken's 'Red Triumph' was looking good in the Miller garden.

'Red Triumph'
'Colors of the Wind' (Blyth)
Lauer 62-2
After my whirlwind visit to the garden, I headed south to the Keppel garden in Salem and that will be the subject of the next On the Road Again post. Stay tuned.

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