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Iris pumila

Iris pumila

March is, of course, an exciting and busy gardening time. Seedlings under the grow lights are getting larger and taking on a more adult appearance. Outdoors, the irises and many other perennials are sending up new growth. In a sheltered bed by the house, daffodils followed the reticulata irises into bloom. In the open garden, it is crocus time, and the first Iris pumila opened on March 22.

I cleaned up the pond and restarted the pump. Dianthus seedlings I had started last summer and overwintered indoors were hardened off and transplanted into the garden.

Iris paradoxa seedlings

Iris paradoxa seedlings

Nine seedlings of the exotic oncocyclus species Iris paradoxa, now one year old but small because I neglected to transplant them last year, now have a new home in a planter.









One-year-old hardy cactus seedlings have been moved from the plastic seedling inserts into a tray that will be kept outdoors on the deck until next spring, when they should be ready to plant out. The planting medium is a mixture of commercial cactus mix, sand, and garden soil.











The main activities in March are resuming watering and clearing away last year’s dead foliage and pulling up the cool-season weeds.

On the last day of the month, I planted the blue grama grass (Bouteloua gracilis) in the “restoration” area in the back yard. I scattered some native blue flax (Linum perenne lewisii) and California poppies (Eschscholzia californica) in along with the grass seed for good measure.

blue grama grass seed

blue grama grass seed


watering in the grass and wildflower seeds

rets2013February has given us almost “normal” weather this year – consistently cold (although never extreme), and a bit of precipitation (although not as much as we could use). The first of the spring bulbs (Iris danfordiae and other reticulata irises) are coming into bloom now, a few weeks later than in previous years. Outdoors, I’ve prepared the area for the blue grama grass restoration, and burned some weeds and clutter from last year to clean out some areas.

coldframe2013I’m trying something new with the hardy perennial seeds I received from the NARGS seed exchange or purchased locally at Plants of the Southwest. These enjoy a period of cold treatment to stimulate them to germinate in the spring, so I’ve planted them in plastic inserts and set them in an open, unheated cold frame outside. Curious to see if this treatment suits them.

sdlgs_lightsIndoors, seedlings of vegetables, herbs, flowers, succulents and hardy cacti are thriving under the grow lights. A few of the cactus and succulents have not germinated. Perhaps they are waiting for warmer nights?

I’ve noticed just this week that the one- and three-year-old cacti that I’m growing inside are starting their spring growth spurt, getting a little plumper and greener. I’ll resume watering them weekly now.

My new Meyer lemon tree was attacked by gray aphids. A vigorous hosing off outside seems to have addressed the problem, at least for the time being.

Winter is a good time to enjoy some garden reading. I’ve been on an iris history binge this month, working through the American Iris Society bulletins from the 1920s, which are available on line to e-members. I’ve also had the good fortune to acquire a complete set of publications of the Dwarf Iris Society, and have been reading Walter Welch’s DIS portfolios from the 1950s.

snowday1It’s mid-December now. We’ve actually gotten a bit of snow, providing the garden with some welcome moisture. There’s nothing blooming or even very green any more, after temperatures dropped down into the low teens earlier in the month. Some of the plants add a little bit of “structural” interest, however, such as the red-twig dogwood and a gone-to-seed parsley plant I left standing.


red-twig dogwood, still clinging to its leaves

I did some clean-up last weekend, burning two enormous piles of dry weeds (mostly tumbleweeds and chenopods).

My cactus and succulent seed orders have arrived, and the NARGS seed exchange opened earlier today. I found a few irises there that I can use, so put in an order and filled it out with “surprise me” requests in my favorite genera.

Seed catalogs have been arriving, and some of those I haven’t received yet have their 2013 offerings on their web sites. So now I’m planning in earnest for next year, going through the seed inventory I have left from last year, and deciding what new things to try.

snowday2I’ve slowed down the watering on the cactuses indoors, as they like to have a sleepy season in the winter.

While reading Laura Springer Ogden’s The Undaunted Garden, I became inspired to restore a section of the backyard with native blue grama grass. It was once the dominant vegetation in this locality, before farming and overgrazing took their toll. I’m hoping that it will eventually supplant the unpleasant weeds and lend a natural look to the space. I’m planning on underplanting with spring-flowering bulbs for extra color and fun. I’ll post on this project as it goes along next year.

What? Did he say November gardening? Odd as it no doubt sounds to some, for those who love gardening there is a lot to do at the onset of winter.

The garden today, November 9, 2012.

I’ve been neglecting this blog, so I decided to start a series of monthly gardening posts to share what I’m doing as the calendar pages turn. Will I keep up with this? We’ll see.

The first frost here was a month ago, so the vegetable garden and tender plants are a thing of the past. There are still things blooming, though: Crocus speciosus, sweet alyssum (Lobularia), violas, and Shenandoah petunias.

Although the frost was a month ago, it hasn’t really been very cold yet: nightly lows around 30 degrees F. There’s a storm coming through this weekend, with temperatures expected to get down to 20 or below, so it’s time to attend to some winter preparations: turn off the solar pump for the pond and bring in the dianthus seedlings still out on the back deck. They are hardy perennials, of course, but they are young plants and will do better indoors during the cold of winter.

Some flowers blooming now.

Last month I brought some things indoors to overwinter: pond plants, and cuttings from Ipomoea vines that I grow in containers during the summer. The cuttings have rooted in a jar of water and are now ready for potting up.

November is also a good time for removing cool-weather weeds: they are unlikely to come back in force this late

in the season.

seedlings from garden-collected seeds of Dianthus ‘Firewitch’ and ‘Arctic Fire’, started late this summer.

On weeks when the weather is relatively mild, November is also a good time for digging new beds and taking on small projects outdoors. I have an old sagging table that I want to replace with a home-made potting bench of cinderblocks and particle board. In preparation, I’ll be taking some bricks from an area where they aren’t wanted and making a sort of foundation for the new work bench.

Overwintering pondplants and Ipomoea cuttings.

This is also the month of the Scottish Rock Garden Club’s seed exchange. The list should be posted soon now, and I can’t wait to dive in and see what’s available. I’ve already received and planted seeds from the Aril Society International seed exchange, and am looking forward to the exchanges of the North American Rock Garden Society, Species Iris Group of North America, and British Iris Society, which take place around Christmas.

I’m also pondering what plants I want to start next year. The Thompson & Morgan seed catalog has arrived, and others will follow in December and January. A friend on an iris discussion group suggested planting sweet peas in flower beds, as they are nitrogren fixers. I think I will try that, so have been poking around catalogs and web sites to check out different varieties.

I also seem to be developing a fondness for growing cactus and succulents from seed. Among the cacti, I’m mostly interested in hardy kinds I can grow outdoors here, particularly New Mexico natives. Contemplating succulents, I want to grow more Lithops, try some Conophytum, and maybe Adenium obesum and Pachypodium saundersii. Oh, and Euphorbia obesa. Did I mention Haworthias? Well then. Spending some time at and the website of Mesa Garden in Belen, trying to converge on a shopping list.

I’m mulling over a few things I learned this year. When starting seedlings, it seems to be better to start early: January and early February. I’m confident I can raise husky plants that way, better able to survive transplanting in New Mexico’s dry and windy spring weather. I also had success this year in planting new irises in pots–just the ones with very small rhizomes that need a more controlled environment than they can get in the open garden. I did this with a few dwarf species and some very small aril rhizomes this year, and it seems to have been good for them.

After being away from serious gardening for a decade, I recently joined (or re-joined) some excellent plant societies: the American Iris Society, the Species Iris Group of North America, the Aril Society International, the Median and Dwarf sections of AIS, the British Iris Society, The North American Rock Garden Society, and the Scottish Rock Garden Club.

Most horticultural societies date from the early decades of the 20th century, or spun off from such groups a few decades later. For nearly a century, these organizations have provided remarkable services to the horticultural world. Besides being “clubs” where people can socialize with others who share their interest, they have brought order out of chaos by overseeing the names of cultivars, spreading information on how to correctly identify species, promoting plant breeding and propagation, helping finance botanical expeditions, and serving to promote the best “finds” and “creations” of specialist growers to the general gardening public. For most of the 20th century, the publications of horticultural society were effectively the sole source of detailed information on the plants they promoted. They were also the principle conduit through which specialist nurseries reached their public.

Today, most such organizations are in a state of decline, in some cases perilous decline. Memberships are shrinking, and with shrinking memberships come shrinking resources (financial and human) to carry on the crucial functions of the organizations. One sometimes hears this attributed to some particular society program being poorly run, or some particular decisions of a governing body being poorly conceived. Such comments, I feel, largely miss the point. This is a universal phenomenon, not a particular one. I think its cause is obvious: the internet.

During the 20th century, horticultural societies operated on a single core principle: membership dues in exchange for information. If you wanted to know what the best new irises were, where to obtain them, or how to grow and breed them, you had to join the iris society and receive their publications (or be close friends with someone who was a member). The societies were the gatekeepers. Once involved, members would find other things the society offered: the judging program, conventions, discussion groups, and so on. But the basic equation was “pay your dues to learn about irises”.

The internet has completely undone this basic equation. The plant societies are no longer the gatekeepers. I can go on line and learn more about irises than I can from a decade of society publications. Don’t misunderstand: the publications are excellent and I enjoy them immensely. It’s just that they are no longer a unique source of information. They are a supplement, and a comparatively expensive and inconvenient supplement in comparison with online resources.

I don’t know of any group that has not recognized the importance of a vibrant online presence in attracting the attention of potential members today. Projects like the forum of the Scottish Rock Garden Club and the AIS Iris Encyclopedia have become phenomenal resources and hubs for enthusiasts around the world. But although embracing the internet is necessary to keep the horticultural societies relevant, it is not sufficient.

Why do I say that? Because having a vibrant online presence cannot, in itself, reverse the trends of declining membership. If the online resources provided by the society are open to all, then the basic problem remains: there is no need to join and pay dues to get the information. If the resources are made members-only, then the society shuts out the very people it intends to attract: potential members. If there were no alternatives, people could be lured into paying dues for access to a web site. But there are, in fact, plenty of free alternatives. Some are of dubious quality, of course. But the basic point remains. Today, if I have a question about irises or rock gardening or plant breeding or species identification or anything else, I  can have my answer in a few minutes without having to “sign up” for something (which many people resist on principle) or pay for anything.

I don’t see a clear answer. Maybe we should just recognize that we are approaching the end of an era, and let the dinosaurs die off, their archives surviving as reminders of a very different era, when information was a scarce resource. Alas, these societies do more than provide information. The American Iris Society maintains the cultivar registration database, operates an important judging and awards system (flawed, perhaps, but vital nonetheless for promoting the many different types of irises), and sponsors various scientific and horticultural projects. It would be sad indeed to return to the fragmented condition of the 19th century, where there is nothing beyond individual gardeners and commercial nurseries to foster our love of particular plants.

The frustration is parallel to what we are experiencing with regard to brick-and-mortar bookstores. I love them, don’t want to see them go, but don’t see how they can successfully face the economic realities of the information age and survive.

The only glimmers of hope I see are in the examples of societies that offer tangible benefits, beyond information: seed and plant exchanges, for example. If the only way to obtain a choice species that is not available commercially is through a plant society, enthusiasts will join. I don’t know if this single strategy is something that can, by itself, keep the societies relevant into the future, but it’s at least a model of the kind of thinking that will be needed. To survive, horticultural societies must move beyond the dues-for-information paradigm that propelled them onward through the 20th century and find a new paradigm.

If I knew in detail what the new paradigm is, I would shout it far and wide. But I don’t. I’ll wager, though, that by the middle of this century horticultural societies will be either radically different than we know them today or gone altogether.

Anyone who becomes interested in perennials quickly encounters the USDA hardiness zone map, which is ubiquitous in books, catalogs, and nurseries. The idea is that the minimum winter temperature in a given location can be used to select plants that will survive most winters. Of course, there are usually some caveats given about snow cover, microclimates, and so on. And not all nurseries list the same zone rating for each plant. I’ve seen a couple that seem to rate anything they don’t know about as zone 9!

People apparently take this system very much to heart. It may be the only information a catalog gives to indicate the plant’s requirements – it’s obviously regarded as a terribly essential datum. Perhaps it’s our love affair with numbers, or the sense of security that comes from “knowing” which plants will survive and which ones won’t. Experienced gardeners, of course, know that you can lose some plants rated for a colder zone and successfully overwinter some rated for a warmer zone. I started wondering how useful these hardiness zone ratings really are. How well does the zone rating actually predict survival?

Last year we had one of our coldest winters on record. The temperature dropped to -18 Fahrenheit at the beginning of February (with no snow cover), and the lows stayed below zero for a number of days afterwards. This is about the lower limit of hardiness zone 5. A simplistic interpretation of the hardiness zone ratings would imply that most plants rated for zone 5 or lower would survive, and that those rated for zone 6 or higher would perish.

What really happened? Well, I made note of how many of each particular plant survived in my garden: 0 if none survived, 1 if all survived, and, for example, 0.5 if half of them survived. I also used a 0.5 if the plant survived, but was so damaged that it was effectively set back a year in growth. I then plotted this “survival rate” for each plant against its hardiness zone rating. (It’s a limited amount of data, but I intend to add to it each year.) The result is interesting:

The best-fit line running through the graph demonstrates that there is in fact a trend in the expected direction: higher zone ratings correlate with reduced survival. But the scatter of the points themselves makes an even stronger point: for any given plant, the hardiness zone rate is a very unreliable predictor of survivability. There were zone 2 and 3 plants that fared no better than the zone 7 plant!

In William Cullina’s excellent book Understanding Perennials, there is an explanation of the mechanisms that plants use to survive freezing temperatures. Truly tender plants (think of tomatoes or basil) simply cannot survive prolonged temperatures below freezing, because the water in their cells turns to ice and expands and destroys the cells. Some plants have chemicals in their cytoplasm that act like antifreeze and prevent freezing, even down to temperatures as low as 20 degrees. But to survive colder temperatures than that, the antifreeze strategy alone is inadequate. At lower temperatures, the cells will freeze, and the plant needs specially designed cells that can freeze without being destroyed (by shriveling to make room for the ice crystals, or by having particularly tough cell walls). If a plant can survive losing its top growth, that is also helpful, because the soil temperatures do not swing as low as air temperatures, particularly under an insulating cover of snow.

Cullina also describes how the timing of cold weather can effect hardiness. No plant is fully hardy when in active growth. Plants must prepare for cold weather in the fall and then return to growth in the spring. If the timing isn’t right, the plant can die from an autumn or spring cold snap, even if it could survive much lower temperatures in mid-winter.

The upshot of all this, in my view, is that the concept of hardiness zones gives a completely unwarranted false precision to a matter that is really pretty hard to quantify. Especially when we start talking about zone 5a or 5b, it seems like what some of us in the sciences refer to as “sharpening the marshmallow”. I think gardeners might be better served by a much loser set of terms, such as “tender”, “semi-hardy”, “hardy”, and “extremely hardy”. About the only solid advice I’m inclined to give people about selecting perennials is “If you live where it’s below freezing a lot in the winter, it’s probably a waste of time to try anything rated for zone 8 or higher.”

Mostly, we just have to live with the fact that we don’t know what will survive any given winter.

Welcome to Telperion Oasis, Tom Waters’s gardening blog. The Winter Solstice seems a nice time in the cycle of the seasons to begin a gardening blog. There is snow covering the garden now, and I’m spending lots of time indoors looking at gardening books, back issues of the Scottish Rock Garden Club journal, and visiting seed exchanges and nursery websites.

Winter is a time of anticipation, planning, and reflection. The collection of irises I obtained for my breeding program is essentially complete, and I’m looking forward to seeing them all as established plants in coming years. I’m also dabbling in rock gardening, having built a modest berm in the garden last year. It will be interesting to try out different rock garden plants and see which can handle our hot and windy spring weather.

Although winter cold can threaten the survival of plants in the garden (I lost a number of things last year when the temperature dropped to -18 F at the beginning of February), it poses less threat here in northern New Mexico than does summer. It is a time of trust and faith. The plants are dormant or nearly so, and gradually melting snow provides some valued moisture to the soil. Perennials planted last year that come through the winter will be established and settled, ready to come into their own next year.