Becoming a Plant Sleuth/ How to Grow Bearded Iris

If your new to gardening this spring, welcome. There is so much to learn and discover! 

After you've been gardening for a while, you begin to realize that there are some plants that are difficult to track down. I really want to expand my collection of hellebores this spring, but they are surprisingly hard to find at local garden centers and nurseries.  The reason? I believe that's because hellebores have finished flowering well before the majority of shoppers make their first purchases of the season. 

Hellebores at the Toronto Botanical Gardens

A lily in my garden.

Other plants have the opposite problem. They bloom sometime after June when the majority of consumers have already made their buying decisions. Lilies are a great example. They typically don't flower until July. On top of this disadvantage, their strong central stem looks a bit awkward and unappealing in a plant pot. The sad thing is that lilies are actually a wonderful addition to the garden in mid-summer.

I did find some trilliums at a local garden center this year, but they were teeny-tiny.

Growers naturally prefer plants that provide a quick return that is measured in days or months but not years. A trillium can take seven years to go from seed to a decent-sized, flowering plant. That's a long time to wait for a payday!

Some plants just don't get enough good press. Simply put: not enough people know about them. Native plants are a great example. If asked to name ten native plants, many people would struggle to move beyond Echinacea and Rudbeckia. This lack of demand means fewer companies grow them. Unfortunately, there is nothing more likely to fit easily into your garden than a plant that thrives in your local area.

By now, I think you'll get my point. It can be a challenge to find some of the plants that might be on your wishlist. Don't let that limit you! They are out there just waiting for you to discover them. As your knowledge and experience grow, you'll discover that you need to become a bit of a plant sleuth to track down some of those more intriguing options. 

Searching for interesting and unusual plants might sound a bit like a chore but the hunt can actually be fun and rewarding. The internet makes it easy to seek out specialty nurseries, growers, and mail order companies. 

Lots of these specialty growers offer open houses. As I have written many times in the past, there is nothing like seeing a plant right before you. You don't have to rely on the accuracy of a photograph in a catalog to gauge the flower's true color. When the plant is in front of you, it is also easy to get a clear impression of its mature height and spread. Often I find I have overlooked a plant or combination of plants until I have seen it in someone else's garden.

Bearded Iris 'All the Right Reasons' 

Once the pandemic is behind us, I would encourage you to visit some of these small businesses in person. Last year, I had the pleasure of attending one of the few open houses of the summer. This small business owner had devoted a few acres of his country property to growing irises for sale. Without a doubt, the rows of irises were a labor of love.

Bearded irises are one of those great perennials that don't always make it into garden centers. An iris's bloom stalk is tall and the flowers are easily damaged. It's best to plant irises in late summer/early fall, which is well after the time that nurseries experience the height of retail traffic. If you are lucky enough to find bearded irises, it would likely be a limited selection and nothing like the variety available at this iris farm.

If you are shopping online for bearded iris, it will be easier to read the catalog descriptions if you know these basic parts of the flower.

Tall Bearded Iris 'Queen's Circle' on the left and 'Gypsy Romance' on the right.  

The irises at the far end of the country property.

Tall Bearded Iris 'Falcon Pride'

With satin petals that shimmer in the sunlight, the flower of a tall bearded iris is an exquisite thing to behold. They are perhaps the most iconic iris, but they aren't your only option.

Here's a look at the range of bearded iris available:

MDB: Miniature Dwarf Bearded Irises are the smallest and earliest of the bearded irises to bloom. They grow up to 8 inches tall and have flowers that are three inches or smaller.

SDB: Standard Dwarf Bearded Irises bloom after Miniature Dwarf Iris and usually finish flowering just as the Intermediate Bearded Iris are reaching their peak. SDW reaches a height of 8 to 15 inches tall and has blooms that are 2-4 inches in size.

IB: Intermediate Bearded Irises are 16 to 28 inches in height. The flowers are 3.5-5 inches in size and extend up above the foliage for a nice display.

MTB: Miniature Tall Bearded Irises are 16 to 18 inches tall and have flowers that are approximately 6 inches. The flowers are fragrant and are often used as cut flowers.

BB: Border Bearded Irises are 16-27 inches in height and are more resistant to wind damage than Tall Bearded Iris. At 5 inches the flower size is a little smaller than TB.

TB: Tall Bearded Irises are the last of the bearded iris to bloom. They are 27 inches or more in height.

'Indigo Seas'

Mystery

Planting a Bearded Iris:

The best time to plant bearded iris is in July, August, or September. To ensure your iris will make it through winter, be sure to plant it at least 4 weeks before the first hard frost. Typically a bearded iris will bloom a year after it is planted.

Iris like full sun (6-8 hours of sunlight). The exception might be a hot climate where bearded irises might benefit from light shade in the afternoon.  The only other requirement is good drainage. If your soil is poorly drained, add organic matter to improve drainage.

Plant your rhizomes at least 12 inches apart. Crowding them can create an impressive display, but you'll have to dig your iris up and divide them after just a couple of years. Spacing irises properly also encourage good air circulation and helps prevent disease.

If your iris is in a nursery container, remove it from the pot without disturbing the soil. Plant it at the same level or even slightly higher in the ground. Be careful not to cover the rhizome with soil. Water well. Continue to water every few days for about a week. Then water weekly until the iris has rooted.

Planting a bare-root bearded iris is a little more tricky. If the roots are looking a little wrinkled you can rejuvenate them by soaking the rhizome in a shallow pan of water (1/4 to1/2 an inch of water) for a couple of hours just before you do your planting. Irises like to have the top of their rhizomes visible to the sun. Dig a planting hole and fashion a hill of soil in the middle. The mound of soil should come up to ground level. Center the rhizome on top of the mound and spread out the roots down the sides of the hill. Bury the roots taking care not to cover the rhizome. Water well. Continue to water every few days for about a week. Then water weekly until the iris has rooted.

Tall Bearded Iris, 'I'm Back' 

Tall Bearded Iris, 'Splashacata' 

Tall Bearded Iris, 'Dancing Star'

Ongoing Care

Water
Established clumps of bearded iris do not need supplemental water. They should be fine with natural rainfall unless there is an extended period of drought.

Fertilizing 
Generally speaking, bearded iris will do well in average garden soil and do not need regular fertilizer. If your soil is really poor, a light application of fertilizer can be added in early spring and again a month or so after bloom. Superphosphate or a well-balanced fertilizer (with an NKO ratio of 10-10-10 or 5-10-10) are two good options.
There are a couple of fertilizers that should be avoided. A fertilizer that is high in nitrogen can encourage lush growth that is susceptible to bacterial soft rot. A weed and feed fertilizer should also be avoided.

Do not mulch!
Mulch locks in moisture and can cause the soft rot of your rhizomes.

Avoiding Potential Problems
To avoid problems with disease and pests keep your iris clear of garden debris. Remove any dead foliage and after your iris finishes flowering, snap or cut the flower stalk off at the base. In the late summer/fall, prune back the foliage to discourage over-wintering pests.

Tall Bearded Iris 'Ravissant'

Tall Bearded Iris, 'Old Black Magic'

Iris Borers
Adult borers are nocturnal moths that lay their eggs on garden debris in late summer or fall. They hatch into one-inch-sized larvae that chew into the leaves and then eat their way down to the rhizomes. Borer damage is often seen as notched wounds or slimy, wet-looking areas on the leaves. Once they eat their way down to the base of the plant, they begin to hollow their way through the rhizome. In August they pupate in the soil and hatch into more adult moths.

To deal with this pest, I have learned to keep the rhizomes clear of any debris throughout the growing season. I also try to catch the larvae in the spear-shaped foliage by removing any slimy leaves.

Bacterial Soft Rot
It is hard to imagine anything more putrid-smelling than mushy rhizomes infected with this fungal disease. Too much nitrogen in the soil, garden debris around the base of the plants, and too much water are all possible causes of this problem.

Dig up the infected plant/s and cut away the rotten parts of the rhizome (throw the infected sections in the garbage–do not compost them). Allow the cut areas to sit in the open air for a day or two. You can also disinfect the wounds with a solution of 1 part bleach to 9 parts water.

Bacterial Leaf Spot
Small pale spots on the foliage are a sign of a Bacterial Leaf Spot. Sadly there is no cure. Remove any infected plants and wash your tools with a 10% bleach and water solution.

Irises are exquisite flowers, aren't they? 

Sadly, with the ongoing lockdowns, it seems like this will be yet another summer when open houses are impossible (here in Ontario, at any rate). For now, an online search for bearded irises may be your best bet. Typically orders are placed in May and June and are shipped in late summer for fall planting. 

I think you'll find that irises worth doing a little plant sleuthing!

A Little Cheat with Spring Bulbs

Though warm weather seems to have arrived early here in Southern Ontario, I remind myself that we are only entering the second half of April. Not two years ago we had a snowstorm in the third week of the month. 

This spring we had really pleasant weather up until the end of March when strong gusts and a sudden dip in temperatures made working outside rather unpleasant. At night, the thermometer dipped below zero degrees Celsius. Though it's warmed up once again there is no predicting that the fine spring weather will last.

Over the last couple of years, I've been experimenting with options that can handle the blustery weather we sometimes have in April. I've discovered that there are a few tricks that winter-weary Canadian gardeners can put to good use. 

The daffodils with flower buds in the second week of April.

For guidance as to what to plant, I look to my garden for clues. If the hyacinths and daffodils have flower buds in amongst a good few inches of green growth, it tells me it's safe to think about using pots of forced daffodil and hyacinth bulbs to fill my empty flower pots. 

Tulips in the second week of April.

Generally speaking in the month of April, it's usually a bit early to think about using forced pots of tulips in my container plantings. Again, if I look to my garden, the growth of the tulips is always well behind that of the daffodils. If the vast majority of tulips aren't showing more than a couple of inches of green growth, that tells me it's better to hold off for a week or maybe two before I think about putting pots of blooming tulips outdoors. This year spring is exceptionally mild and I think gardeners in my zone might easily get away with using pots of forced tulips outdoors.

When hyacinths are tightly closed it can sometimes be a challenge to guess their flower color. White flowers have lime green buds. Purple flowers have flower buds that are inky-green.  Green buds that have a dusty rose cast will be pink.

When the month of April proves to be a really cold one, I like to shop for pots of forced bulbs that have tight flower buds that are just beginning to peek up over short green foliage. If the weather remains cold, the bulbs slow down and hold back their flowers. Even though the arrival of fully open blooms may slow, the forced bulbs will still be a little ahead of the regular bulbs planted in the garden.

And as well as being the safest choice, less developed flowers will last a little bit longer than flowers that are already at their peak.

Here's a step by step:

•When I get my pots of forced bulbs home, I check to make sure they are well-watered (so often I find plants at the grocery store are as dry as can be).  Next, I ease my bulbs into the cold by putting the pots outside during the day. 

• For the first few nights, I bring the flowerpots onto our enclosed porch each evening (as an alternative, you could also place them in an unheated garage or even in the trunk of a car. Just be sure to remember they're in the back of your car before you head out!) 

• If it's super cold (below zero Celsius), I might even bring the bulbs inside for the night or cover them (horticultural fleece or even an old sheet will do).

I often plant the bulbs as they are right in their pot. 

• Once my pots of bulbs have acclimatized to outdoor temperatures, I plant them up. This can be done in a couple of ways. You can sink the bulbs, pot and all, right into your container planting. This makes it easier to lift them out once they've finished flowering. 

Alternatively, you can remove the plastic pot and plant the bulbs directly into your container planting Don't worry about teasing out the roots. Leave them as they are unless you want to break up the bulbs and plant them individually.

Companions for Forced Bulbs

Cheerful pansies are one of the first annuals to arrive at garden centres. They're pretty affordable and can handle cold temperatures like troopers. If I can find them, I prefer flats of smaller plants because they are the most economical. 

Ranunculus

Pussy Willow branches and pink primula on the right.

Other annual options you might consider could be primula, alyssum and ranunculus. Ranunculus may object if the temperature gets really cold, so you might want to cover them if the weather changes for the worse.

Placing three or five Pussy Willow branches in the centre of my arrangements is my favourite way to add some height to my spring containers. Other options might be Red or Yellow-twig Dogwood or Curly Willow branches.

Other Ways to Use Forced Bulbs

Last fall we were so busy with interior renovations and garden projects, there was little time to plant spring bulbs. If like me, you didn't get around to planting bulbs in the fall, there is still something you can do. 

If, for instance, your garden is looking a little green, you can always inject a little instant color by planting a few pots of forced tulips in amongst your perennials. The tulips will look good for a couple of weeks while the perennials around them continue to develop and move into their bloom phase.

Forced tulips are not reliably perennial, so this is just a quick fix. Once the tulips have finished flowering, add the spent to your compost pile.

As well as filling flowerpots, you can also use forced bulbs in window boxes.

Every spring I tell myself to take pictures and make notes so when fall arrives there is no guesswork as to where to add new bulbs. Despite my best intentions, the spring season is always so busy I never seem to get around to that important note-taking. As a result, I find myself struggling to remember where there were holes in my bulb planting schemes every fall. 

Last spring I tried a new idea that was fairly successful. I filled some of those bare spots that needed bulbs with the spent daffodils and hyacinths from my container plantings. 

A pot of forced daffodils was transplanted into the garden last year and has come 

back again this spring quite nicely.  

Despite the wisdom that says forced bulbs won't return, I have had decent luck getting forced hyacinths and miniature daffodils to return the following spring. Forcing bulbs to bloom indoors is hard on them. Placing them into an outdoor setting where they are allowed to follow a normal cycle improves the odds they will return the following spring.

 Once the flowers have started to fade, I remove the bulbs from my containers, cut off the blooms and plant them in the ground at a depth suitable for the type of bulb. It's very important to allow the foliage to remain exactly as it is. The foliage will feed the bulb that produces next year's flower. 

Not every forced bulb returns, but I count it as a bonus when bulbs that gave life to my containers return for a second show.

P.S. The thermometer dropped last night and we awoke to a blanket of snow. On the plus side, it has already started to melt.

Our white magnolia was gorgeous this year. One woman even stopped to take a picture.

Pink Star Magnolia, Magnolia x loebneri 'Leonard Messel'

A Work in Progress

A few years ago, we experienced a winter ice storm that sent huge tree limbs crashing to the ground. Two mature trees were so badly damaged they had to be removed. 

While the loss of the huge tree in the back corner of our property was dramatic, the loss I felt the most keenly was the small tree just inside the back gate. 

Before the tree came down, the little courtyard at the side of the house was always one of my favourite parts of the garden. This had nothing to do with the way it looked and everything to do with how the courtyard made me feel. The leafy tree canopy always made this spot wonderfully cool on a hot summer's day. The moment you entered the back gate, the contrast in temperatures between the full sun front yard and the comfort of the shaded backyard always elicited a sigh of relief and appreciation. When it's really hot, the sun can be oppressive. The shade, especially when combined with a light breeze, is so welcome.

The Pathway

Once the tree was gone the courtyard changed completely. My hostas fried and turned brown. Goldenrod, Creeping Thistle and other weeds quickly transformed the gravelled pathways into a weedy mess. A replacement tree died during its first winter. My once peaceful courtyard became a source of stress and frustration.

There are gravel pathways in a number of places in the back garden. This is the view from the back door late in the summer. I hand-pull the weeds in the gravel and it's a ton of work!!

One of the reasons the weeds got out of hand was my hesitation about a suitable replacement for the gravel pathway around the base of the tree. My overall experience with gravel pathways has been a troubled one. If you lay down a foundation of landscape fabric and cover it with gravel it looks good for the first few years. Eventually, tiny pinholes develop in the cloth and weeds take advantage of any opening. Even if you rake the gravel routinely, leaf litter and other debris falls onto the surface and breaks down into a fertile medium ideal for more weeds. Your choice becomes hand pulling the weeds or spraying them.

I recently watched an interview with head gardener Asa Gregers-Warg about Beth Chatto's renowned gravel garden in Essex, England (Note: though the gravel in my garden is only in the pathways, the general principals at work are pretty similar). While this section of Beth's garden is famously drought-tolerant, Asa says it's also the most labour intensive parts of Chatto's garden as a whole. I can believe it! The free-draining gravel makes it an ideal place for weeds to thrive. 

The video interview by Alexandra of the Middle-sized Garden Youtube channel and blog.

Here's what I have learned through trial and error. The best way to keep weeds at bay is to deprive seedlings of light. And the best way to deprive them of light and make it hard for them to sprout is by making the surface they must penetrate hard and compact. It's impossible to compact pea gravel. 

The pathways at the Halifax Public Garden. Limestone screening is crushed limestone chips (1/4") mixed with limestone dust.

The pathways at the Halifax Public Garden

Eventually, I want to try working with something finer than gravel. Lime screenings, which are often used for pathways in public gardens, are something I want to experiment with in the future. For now, I have switched to natural cedar mulch to make my circular pathway around the central tree. 

Piper taking a break on the mulched path that encircles the Magnolia tree and the garden at its feet.

To create the path, I simply laid down a thick layer of natural cedar mulch. Next, I compacted the mulch with the flat side of an old-fashion garden rake. If the mulch breaks down or gets disturbed by the dogs, I can always add a fresh layer and repeat the compaction. So far, I am fairly pleased with the results. The compacted cedar mulch has kept the weeds at bay nicely (I pulled no more than a couple of weeds last summer). 

The one drawback is the aesthetic. There is also something about the neutral look of gravel that is so pleasing. Mulch may be soft to walk on, but it looks rustic and woodsy. Gravel makes a pleasant crunch underfoot. 

For now, I am sticking with the mulch for the pathway around the central tree. I plan to experiment with limestone screening in a small area. If it works out, I may remove the mulch and replace it with the crushed limestone.

Additional Privacy

I know there is a commandment that we should love our neighbours, but depending on the people next door, that can sometimes be a bit of a challenge. Adding a degree of separation between properties, a fence or a privacy screen can ease the strain of maintaining a good relationship with the folks next door.

The fence that skirts the perimeter of our backyard is a standard height of 6 feet. Unfortunately, there is still a clear view of the house next to ours. To add an additional degree of privacy, we decided to add a tall screen topped with an arbour. The overall layout of the structure was intentionally designed to fall entirely on our side of the shared fence.

Two verticle posts, set in concrete at the base, form the upright support for famed panels of wooden lattice. At the top, there is an arbour with a wooden ladder that runs along the top (2 x 2" boards cut on the front-facing end at a 45-degree angle). 

A square lattice is also an option.

The lattice comes in 4'x8' sheets that can be cut down to suit.  Depending on the retailer, the weave of the lattice may vary from a more open crosshatch or a more dense "privacy" crosshatch. As well as a diagonal lattice, there is a square option as well. 

We chose to use a diagonal privacy weave because it reflected the top section of the backyard fence. Hopefully, the arbour will be covered with a climbing vine one day soon. 

The Plantings–A Restricted Color Palette

We ended up replacing the tree that had been lost with a star magnolia. I always wanted a pink magnolia and this seemed like the perfect opportunity to finally plant one. 

Sadly, the new tree will take years to reach the size of its predecessor. So I started to wonder if there was a way to recreate the old feeling of privacy and comfort without relying on a tree.  It struck me that a quiet color palette can also feel soothing. So rather than planting my usual mix of colors, I decided to limit the palette. Much like the shade that had characterized the courtyard previously, the color white always feels fresh.

The big decisions made, I thought long and hard about what I wanted to do in terms of perennials and shrubs. Most of the old shade-loving hostas found new homes elsewhere in the garden. Only two were left right at the base of the new tree (small as the tree was, it still provided a little shade).  The vast majority of new plants would have to be sun-lovers (at least until the new tree matured). 

Salvia nemorosa 'Lyrical White' forms a compact clump of bright green leaves and has white flower spikes in early summer. Removing faded flowers encourages good reblooming. Fairly drought tolerant once established. Adaptable to a range of soil and moisture conditions. Divide every 3 to 4 years in spring. Full sun. Height: 50-60 cm (21-23 inches), Spread: 50-60 cm (21-23 inches). USDA Zones: 4-9.

Two old-fashioned annuals: Dusty Miller and Alyssum.

Tiny White Scilla

Plantings by Season (Full sun unless indicated otherwise)

Spring Flowering Bulbs:

Thalia daffodils

Scilla (white)

Species Tulips (white with a yellow throat)

White Crocus

Left to Right: Solomon Seal, Polygonatum, Dublin Patio Peony and Dicentra spectabilis 'Alba'.

Spring Flowering Perennials and Shrubs:

Double White Lilac (unknown variety)

Frilly White Peony, Paeonia 'Duchesse de Nemours' 

Dublin Patio Peony (dwarf single white peony)

Solomon Seal, Polygonatum (in part to full shade)

Dicentra spectabilis 'Alba', White Bleeding Heart (part-shade)

Service Berry tree, Amelanchier Arborea

Catmint, Nepeta 

Climbing Rose (only the rootstock took so this needs to be replaced)

Moss or Creeping Phlox

Summer Flowering

White Drift® Rose 'Meizorland'

White Cranesbill Geranium, Geranium x cantabrigiense 'Biokovo'

Salvia nemorosa 'Lyrical White'

Veronica 'Magic Show White Wands'

Meadow Rue, Thalictrum aquilegifolium 'Nimbus White' (part-sun)

Chinese Meadow Rue, Thalictrum delavayi (part-sun)

Hydrangea paniculata 'Bobo'

Late Summer/Fall Flowering

Hydrangea 'Bobo' (in part-sun)

Hydrangea paniculata 'Bombshell' (in part-sun)

White Echinacea purpurea 'PowWow White' 

Alyssum 

Rose of Sharon, Hibiscus syriacus 'Diana'

Flowering Lamb's Ears, Stachys byzantine and Alyssum

Foliage Plants:

Assorted Hosta (part-sun to shade)

Boxwood

Euonymus

Lamium 'White Nancy'

Non-flowering Lamb's Ears, Stachys byzantina 'Silver Carpet' 

Flowering Lamb's Ears, Stachys byzantina

Ostrich Ferns (shade)

Japanese Fern (part-sun)

The face pot is concrete but never seems to crack even though I leave it in place during the winter. I got it at the now-defunct Humber Nursery.

Container Plantings

There isn't a whole lot of space available for plants in this tiny area, but it is the first thing you see when you open the back gate, so it's nice to have flowers throughout the season. Container plantings seemed like the perfect way to add a little color.

The beige urns (with the white geraniums) are fibreglass pots I got years ago at Canadian Tire. They are wonderfully lightweight. I leave them out all winter and they have never cracked. 

Ornamental Kale, Round-leaved Oregano or Kirigami (Origanum rotundifolium), a decorative pepper and trailing Swedish Ivy (Plectranthus verticillatus).

The metal plant stand I've owned for years.  To give it a new lease on life, I applied a fresh coat of white spray paint.

I got the brown ceramic pots in a 30% off sale. I chose a neutral color because it fits with my goal to keep the area quiet. 

The Fountain

The focal point of our new privacy screen is an old cast-iron fountain. It developed a crack that couldn't be repaired, so I've turned it into a planter. Perhaps at some point, it would be nice to have the splash of a working fountain, but for now, this old lion will do. 

Rust-oleum Multicolor Textured spray paint in the color "Desert Bisque" 

After hanging on the fence for years, the paint on the cast iron lion was peeling. I cleaned, sanded and primed it. Then I sprayed it with textured paint. This took a bit of work but I was really happy with the result.

What I'd Still Like to Change

As with anything that is worthwhile, a garden takes time. At some future point, I'd like to replace the mulched path around the tree with something a little more formal. The rocks that edge the flowerbeds were free. While you can't argue with that, I feel it's a bit too cottagey for the look I was trying to achieve.

At the moment, the Magnolia tree blocks the view of the new privacy screen but at least that doesn't require a change– just time and patience for the tree to grow. Eventually, it will dominate the space casting what is now full sun back into the shade. Eventually, the plantings will have to change to suit the lower light levels. Like housework, a garden is never done!