Mugshots: 4 Siberian Iris

Four of my siberian iris plants bloomed last month. 'June to Remember' is pictured above. The intense blue of these flowers really catches my eye in the garden, and their elegant carriage reminds me of butterflies. I ordered this plant two years ago from Joe Pye Weed's Garden, a small nursery in Massachusetts that specializes in siberian iris and hybridizes new types each year. Click on the nursery name to get to their website.


Here is a different view of the blooms. I look forward to the great display I'll enjoy in a few years, when the 25 inch tall clump gets wider. One drawback to these plants is that they bloom for a relatively short period each year. However, siberian iris leaves form grass-like clumps that are good low-allergy substitutes for ornamental grasses in my garden design.


The blue-violet flower above comes from 'Worth the Wait', another iris that came from JPW's Garden. These deep colors make my heart skip a beat.


And here is a view from above the flower. 'Worth the Wait' grows to 34 inches high and is supposed to rebloom, though my young plant hasn't done so yet. Siberian iris take a couple of years to get established. All of my plants have been transplanted at least once, which has set them back, poor things!


This white flower is 'Rolling Cloud', also from JPW's Garden. It grows to be 29 inches tall and has a touch of yellow around the base of the petals. Siberian iris grow well in full sun to part shade, and I've learned from experience that they don't appreciate intense heat or very dry conditions (though they don't need as much water as Louisiana or Japanese iris).


These last three pictures are 'Tanz Nochmal'. You can see that it's very similar to 'June to Remember', though the color is less saturated and has a touch more turquoise in it. The standards (the top part of the flower) are a little lighter than the falls (the bottom of the flower). The blooms on all of my siberian iris plants are about 4 inches wide.


I also have little starts of 'Blueberry Fair' and 'Just Because' siberian irises in my garden. I received these from Schreiner's Iris last fall, and they didn't bloom this year. Siberian iris have a great range of colors, but I've been drawn to the blues. Pictures of 'Blueberry Fair' on Schreiner's website show that it will probably be very similar to 'June to Remember'. 'Just Because' is a lighter blue-violet than 'Worth the Wait'.


If you're looking for low-allergy, upright forms for your garden and are willing to be patient for a couple of years while they get established (though they'd grow faster in areas with longer growing seasons than mine), siberian iris would be a nice addition to your garden. Check out JPW Garden and Schreiner's Iris Nursery to see more information and options.

A Sensible Approach to Plant Pollen Allergies

I don't want to be an allergy fanatic, and you probably don't want to be one, either. But the American Academy of Asthma, Allergy and Immunology (hmm, I think they could use a shorter name, too) reports that more than 35 million Americans are affected by seasonal allergies, often known as hay fever, and that number is growing. Informed gardeners, landscape designers and others in the hort world have a great opportunity to reduce this problem through the advice we give to others and the plant choices we make for our own landscapes.
But information about allergy-causing plants can be difficult to find; I've certainly never seen a plant tag with allergy information on it. In lieu of carting around a reference book each time you visit a nursery, here are a few ideas to point you toward low-allergy plants.


Some trees - like this maple - produce huge amounts of pollen.

1. Focus on Trees. A large tree that merits a poor allergy rating (10 is the worst on the OPALS scale) will produce much more pollen than a perennial with the same rating. In addition, if you find that a perennial is aggravating your allergies, you can easily pull it out. You might not have the resources to do the same with a mature tree. Choosing to plant trees that cause little or no allergy will make the biggest impact on the pollen problem. If you spend only one hour studying plant allergies, spend it researching the trees you are considering for your landscape.

2. Be a Feminist. Turn your mind back to high school biology, when we learned that some plants have only female parts, some have male parts, and some have both. Plants with just female parts do not produce pollen to cause allergy, while their male counterparts produce large amounts. Male plants (especially trees) are popular choices because they do not produce messy fruits, but they often have horrible allergy ratings. Be cautious about planting 'fruitless' male trees or shrubs.


Showy flowers generally don't produce much pollen.

3. Double Your Delight. Here's some good news for flower-lovers: plants that produce small amounts of sticky pollen must attract insect or bird pollinators with their brightly colored, showy flowers. That means the plants with the most beautiful flowers often cause little allergy. When some of the pollen-producing anthers have morphed into extra petals, producing a 'double' flower, the flower produces even less pollen.

4. Be Spooked by Ghostly Flowers. The flowers of wind-pollinated plants are usually small and pale green or white (hence the ghost reference). They're often so inconspicuous that you may not even realize the plant has flowers. These plants produce large amounts of lightweight, dry pollen that is carried long distances by the wind until it alights on a moist surface like a plant stigma or a human's nasal membranes.


Trumpet-shaped flowers like Vinca are good low-allergy choices.

5. Turn to Trumpets. Flowers that are shaped like trumpets generally hold their pollen inside where it won't make you sneeze. Choosing plants with trumpet-shaped flowers will be good for your nose, and bees and hummingbirds will applaud your choice as well.

Sorting out low-allergy plants from high-allergy plants is not a simple task, but hopefully these five suggestions will be a helpful way for you to make plant selections that have a positive impact on the pollen allergy problem.

Worst Allergy Plants List

I'm interested in knowing which plants cause allergies because I experience allergies to pollen from grass and several trees. Did you know that repeated exposure to large amounts of allergenic pollen can cause you to develop an allergy to it, even if you don't have one now? Both those people who already have allergies and those who could develop allergies (that pretty much covers everyone!) might be interested in the following list.
I went through Thomas Ogren's "Allergy-Free Gardening" book and picked out some of the plants with a rating of 9 or 10 on the OPALS scale. These are the plants that cause the most allergies. The entire list is huge, so I'm just including plants that are common to temperate climates like mine, plus a few that I remember from my Californian neighborhood. If you live in a mild climate, you'll just have to buy the book to find the worst allergy offenders for your area - including many types of allergenic palms and grasses. Actually, I recommend this book for every gardener and designer.
The plants are listed alphabetically by latin name with common names in parenthesis. In many cases just the male forms are the offenders, as females don't produce pollen to cause allergies. Sorry I didn't do the italics thing but I just didn't have the patience for it on this long list.

Acacia (wattle, mimosa, whitethorn)
Acer negundo 'Aureo marginatum', 'Baron', 'Violaceum' (male box elder)
Acer rubrum 'Autumn Spire', 'Tiliford' (male red maples)
Acer saccharinum (male silver maple)
Agrostis (bent grass, redtop)
Ailanthus (stink tree, tree of heaven)
Alnus (alder)
Ambrosia (ragweed)
Anaphalis (pearly everlasting)
Artemesia (dusty miller, sagebrush, tarragon, wormwood)
Aruncus sylvester
Broussonetia papyrifera (male paper mulberry)
Callistemon (bottlebrush)
Carex (sedge)
Carya (hickory, pecan)
Chionanthus (male fringe tree)
Corema (broom, crowberry, poverty grass)
Cryptomeria japonica (Japanese cedar)
Cupressus (cypress)
Cynodon dactylon (Bermuda grass)
Elaeagnus angustafolia (Russian olive)
Elaeagnus pungens (evergreen silverberry)
Fescue glauca (blue fescue)
Fraxinus (male ash tree)
Gymnocladus dioica (Kentucky coffee tree)
Helenium autumnale (flowering sneezeweed)
Juglans (walnut, butternut)
Juniperus (male juniper, cedar, habbel)
Laurus nobilis (male bay, sweet bay, sweet laurel)
Lycopodium (club moss, ground cedar, princess pine)
Mangifera indica (mango)
Morus (male mulberry)
Olea europaea (olive)
Pennisetum setaceum (fountain grass)
Phalaris (canary reed grass)
Phleum (timothy grass)
Platanus (sycamore, plane tree, buttonball tree)
Poa (Kentucky bluegrass) *if mowed often it won't produce pollen
Podocarpus (male fern pine, yew pine)
Populus (male aspen, cottonwood, poplar)
Quercus (evergreen oak, ie coastal live oak)
Rhamnus (buckthorn, coffeeberry)
Rhus (sumac, poison ivy, poison oak)
Salix (male willow)
Schinus (male pepper tree)
Senecio (cineraria, natal ivy, german ivy, wax vine)
Thalictrum (meadow rue, buttercup)
Zelkova (Japanese zelkova)

After perusing the list, do you notice any plants that have given you allergy symptoms? Are there any that you might need to remove from your landscape? When we lived in California, I often walked past a long row of olive trees on my morning walks. By the end of the row, I usually had a headache, but didn't attribute the problem to the olive pollen until I reread Ogren's book and saw that olives are rated as a 10. I turn to his reference book as I'm considering new plants - especially trees - for my landscape. I'm willing to take medicine and put up with the sniffles in order to continue to enjoy time outdoors, but of course I'd like to reduce the problem by reducing pollen levels in my yard and community.

Professor Ogren has released another book, The Allergy-Fighting Garden: Stop Asthma and Allergies with Smart Landscaping, available here.

Allergy Season Already?!

Is it possible that allergy season has begun here in Spokane, despite freezing temperatures and lingering snow? Unfortunately, coniferous evergreens like juniper, pine, spruce and arborvitae (pictured above) begin releasing pollen in late winter. As a one-woman allergy meter, I have my own way of marking the start of allergy season. Persistant nasal drip, itchy eyes, frequent headaches? Yes, yes and yes. And so it begins.

Coniferous evergreens produce large amounts of dry, lightweight pollen from male cones. Do you see the tiny brown male cones in the picture above? Since these plants don't rely on insects as pollenators, their pollen is designed to fly with the wind over large distances. This type of pollen is especially good at causing allergies because there's so much of it, it stays airborn for a long time, and it sticks easily to moist nasal surfaces.

Not all conifers are equally allergenic. On the OPALS allergy scale (where 10 is the most allergenic), arborvitaes (Thuja) are rated at an 8. But pines (Pinus) and spruces (Picea) are rated at just 4 and 3, respectively. Pine and spruce pollen have a waxy coating that make them less irritating to human noses. So the dwarf Alberta spruces in the above photo probably aren't the ones giving me problems.
Some of the worst coniferous allergy offenders are male juniper and male cypress plants (Juniperus), which are both rated at a misery-causing 10 on the OPALS scale. Chinese junipers were the aesthetic bane of decades past. Thankfully there aren't many of them planted in my newer subdivision. The overgrown junipers below are located several blocks from my home.

If you find your allergies flaring in late winter, you'll find Allergy-Free Gardening, by Thomas Leo Ogren, to be a great help. Professor Ogren has created allergy ratings on numerous plants and gives suggestions on how to find allergy relief. His work is especially important in light of the increasing allergy and asthma problems in the United States.
Someday I'll shell out for a course of allergy-reducing shots. But even after that, I'll stick to plants with low allergy ratings. Best wishes to my fellow - sniff, sniff - allergy sufferers!
You're welcome to use any of the pictures from this post if you'll list vwgarden.blogspot.com as the source.