Jim Shields' Garden Notes
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Blog Home : July 2008

- Rainy Fourth of July

It's a cool, almost chilly, and rainy Fourth of July in central Indiana.

One item on the web I'd like to bring to your attention, as it was just brought to mine. A blog on evolutionary bioloy in the New York Times, on their web site at: http://judson.blogs.nytimes.com/. The author is Olivia Judson, and she clearly knows what she is talking about. On the basis of my first look at it, I can recommend it very higly.

I neglected to get a picture of it in my last entry, but Hymenocallis glauca is also blooming right now. This looks very similar to Hymenocallis eucharidifolia, except for the glaucous (dull blue gray) leaves of glauca and the bright green, glossy leaves of eucharidifolia. I'm trying to cross them, so I brought the pots into the greenhouse, at least till the rain stops for a few days.

Hymenocallis glauca (c) copyright 2008 by Shields Gardens Ltd.  All rights reserved.
Hymenocallis glauca from Mexico

A friend in Brazil asked me about a white rainlily from Florida that he had a picture of. I've ignored rain lilies for the last 5 or 6 years, so my plants are mostly gone. I've put out a request for wild-collected samples of Florida rainlilies (Zephyranthes species) so that I can begin to help my friend identify his plants.

There are several species or possible species of white Zephyranthes in Florida. The most wide-spread is probably Zephyranthes atamasca, which ranges up into the Carolinas. I've received a few bulbs from Nassau county, Florida, already. The kind gentleman even sent a sample of the soil they were growing in. This was very helpful, as I could see that it was mostly fine sand. I modified my usual bulb potting mix accordingly, adding two parts of sand to one part of my gritty mix (by volume).

The various white flowered Zephyranthes listed for Florida include atamasca, candida, insularum, simpsonii, and treatiae. No one is quite sure how many of them are really good species. Rain lilies hybridize so easily that they might all be one species if their ranges and flowering seasons overlap. I'm interested in getting a few wild bulbs of each species to see for myself.

I'm interested in trading for small batches (3 to 12 bulbs) of wild collected bulbs of Zephyranthes, especially from Florida, with preciesly known provenance, including GPS coordinates if possible. Samples of the soil where the bulbs were collected would also be very welcome. Just put about a half a cup in a zip top plastic sandwich bag. Contact me privately before sending any plants. I want to be able someday to do some botany and biochemistry on these plants, so wild collected material is essential. Plants from gardens are of unknown genetic background, and pretty much useless for science. Too many garden plants are actually hybrids.

Good gardening,


- Mulling Speciation

A few months back, I was reading a textbook called "Speciation" by Coyne and Orr. Speciation is the process by which new species arise from pre-existing species. It is the heart of evolution. I got sidetracked by the gardening season, and have not looked at it again until very recently.

The recurring question is whether two new species can arise from an old species without the old species first being split geographically into two or more isolated populations. I find it difficult to envision how a new species could arise in the midst of its parents' population. So far, the book has not shown me any mechanisms for this that I find convincing.

When the old species is first split into two isolated subpopulations, from which new species arise independently of one another, the term used is ALLOPATRY. When a new species arises in the midst of the old species and the two become separate and distinct species in the same geographic area, the term is SYMPATRY.

Allopatric speciation seems to have to be the rule, and if two closely related species now occupy ranges that overlap, then they cannot both have developed in that current range.

When two related species extend their ranges so that they overlap, several things can happen.

1. One is that they can be unable to hybridize. The possible reasons for this are many, from behavioral (for plants, behavior of pollinators) to chromosomal incompatibilities.

2. A second possibility is that their hybrid offspring have poor or no fertility. The hybrids will be at a great reproductive disadvantage compared to the parents, but will be competing against the parents for resources. The hybrids will eventually lose that commpetition.

In either case, the two species are very probably going to remain separate and distinct from each other over the long term.

3. Or they may interbreed freely.

If they can hybridize and if their hybrid offspring are fertile and vigorous, one of the two species is likely to eventually be swallowed up by the other. By "eventually," I mean over several thousand years or several tens of thousands of years.

The whole of North America is a hotbed of evolution because the last glaciers left North America only about 12,000 to 14,000 years ago. That is a short time in the life of a species, but the glaciers have come and gone from here many times over the last 2 million years or so. The constant cycling of environments and climates has probably accelerated the rates of change for the species that live and have lived on this continent.

Here in central Indiana, we were very near the southern edge of the glacier 20,000 years ago, but we were still well under the ice. None of the plants in our woods and fields were growing here 20,000 years ago. They were somewhere else, most likely well south of here. Where they were from 120,000 to 14,000 years ago and how they got back to here after the ice melted would tell the story of their recent evolution.

I'm interested in the species and the recent (last 100,000 years) of the evolution of things like Trillium, Hymenocallis, and Zephyranthes that are native to eastern North America, among other places. I wonder how they got to where they are growing today. I wonder whether they are old species or brand new species. I wonder where they are going.

Good gardening,


- Naturalize Bulbs and Other Bits

First, I want to let you know about the short vieo on YouTube on peeling Clivia seeds. You can find it at: http://www.youtube.com/watch?v=yboAzfmWVKI

Then I thought I'd share my experiences with trying to naturalize bulbs in the lawn. Mixed results, one would have to say. The bulbs went into the lawn in full sun. What made me think of this today? I just mowed the grass (and assorted weeds) over the naturalized bulbs today for the first time this season.

Narcissus in large groups look great in the spring, before the grass has grown much. Once the flowers fade, and the grass starts to grow enthusiastically, you have to compromise. Don't mow that grass as long as the leaves of the Narcissus are still green! Premature mowing means fewer and fewer flowers in each successive year.

Colchicum were planted the same way, and in among the Narcissus in some cases. Again, it is critical to success that the grass be left alone until the Colchicum leaves have turned yellow or brown and started to dry up. In August or September, the large pink cups of the Colchicum flowers in the middle of the manicured lawn look fabulous.

So in spring and in fall, the flowers are definitely worth the field-of-hay look that the bulb patches give to your lawn.

Other bulbs I have tried the same way have not prospered. Some losers (to the grass) include Corydalis solida, Fritillaria meleagris, and Galanthus nivalis. They are not vigorous enough to out-compete the grass for any available light, water, or fertilizer.

Many people naturalize Lycoris squamigera and Peonies in their lawns here, especially in smaller towns and older neighborhoods. For patchy plantings, I'd suggest that the spots with the bulbs or peonies be kept free of grass and weeds all season long, so the hay field look does not develop. Of course, I'm thoroughly accustomed to the hay field look in my own front yard, so I barely notice it. Unfortunately, my wife does notice the tall grass and weeds there, almost as soon as the daffodil flowers have faded in spring.

Passers-by enjoy the flowers in spring and in fall so much that they seem to manage to endure the hay field phase easily. We get many very nice comments on the flowers.

To plant your own naturalized bulbs in the lawn, I would suggest full sun for the plantings. Plant the bulbs in clusters or groups. Remember where you planted them! As a reminder for the first few years, I use metal labels such as from Eon, Charlies Greenhouse, or A.M. Leonard Co. I use the 10-inch markers for most things. For the lawn, push the marker as far into the earth as you can, then bend the top flat to the ground.

The Eon markers are very good and cheaper, but I have not found them on-line. I prefer the ones from A.M. Leonard, which I can order by phone or on line. We use them by the hundreds around here!

While we are on the subject, I'll put in a plug for the Brother P-Touch label makers and the TZ label tapes. We use the series PT-2600 and PT-2700 label printers and the TZ-231 and TZ-251 tapes. The labels come out laminated, and they are very weather and UV resistant. You can look for them at your local office supply store, or get them on-line. We tend to buy them from Image Supply.

Do you have any tips to share? Drop me an e-mail telling about them, and I'll post them in this blog for everyone to read.

Good gardening,


- Conservation by Assisted Migration

Ex situ conservation (moving plants or animals out of their wild habitat to save them) is the most horrible of horrors to many conservationists. So it's quite a shock to learn that a group of conservation biologists scattered around the world proposes that humans may need to assist plants and animals, threatened with extinction by global climate change, to find new habitats.

Reports on this paper can be found in various newspapers, among which is the Los Angeles Times, at: http://www.ajc.com/news/content/shared-gen/ap/Science/SCI_Saving_Species.html

The original article can be found on the Science Magazine web site at http://www.sciencemag.org/cgi/content/short/321/5887/345 if you are a subscriber.

I'm afraid that this is going to be a very inflammatory subject for a long time to come. I see it not so much as a question of science (which could go either way, depending on the specifics) but more as a fundamental conflict between realists and romantics. I would guess that there will never be much agreement on this subject, but we all should nevertheless start thinking seriously about this matter.

The romantics would like the world to again be as it was 500 to 1000 years ago, especially in North America and Asia. Humans would be far fewer in numbers and would live desperate lives. Wild Nature would be much safer. I wonder if they would like to return it to 120,000 years ago, when mammoths, mastodons, saber-tooth cats, horses, and camels roamed North America; and there were no humans anywhere on the continent?

The realists see no hope of slowing the expansion of human population on this planet, let alone of stopping such growth. They see climate change, driven by human civilization and its exuviate, becoming ever more drastic. The speed of such change already seems to be higher than adaptation and natural migration of plants and animals can compensate for.

Dare we intentionally move seeds of plants or breeding groups of endangered animals northward as the temperatures climb? What of exotic invasive weeds and pests? What makes us think the rare ones would survive even if we moved them? I think a large amount of science is needed before anyone rushes out to haul plants and animals from southern mountaintops northward.

It is definitely thought-provoking. I doubt that jumping to conclusions in either direction would be productive in the long run.

Good gardening,


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