Nodding Wild Onion Project

After eight years of trying, it appears that I’m finally learning how to raise captive Nodding Wild Onions, Allium cernuum.  It’s a good thing too, because the last of the wild plants disappeared from Blue Jay Barrens three years ago.  The onions in this pot represent the offspring of six plants taken from the wild and relocated into my prairie garden.  That left only a dozen plants growing in their original location, a site that was too shady for the plants to produce flowers.  You can read about the original relocation by clicking HERE.

The plants in this pot appear to be doing their best to break through the chicken wire barrier and reclaim their positions as wild plants.  There are more onion flowers this year than I’ve had in total over the last seven years.

This spring, I took a few young plants from the pot and relocated them to one of the native plant beds in my vegetable garden.  All of those plants have grown wonderfully.  They are currently sharing the bed with Spider Milkweed, Leavenworthia uniflora, and Draba cuneifolia.  I think the species in that mix should work well together.

Nodding Wild Onions produce lovely blooms that attract a wide variety of insects.  Here we have a beetle, a fly and a bunch of ants.

The most common pollinators this year are small green Sweat Bees.

Butterflies are not frequent visitors of the onion flowers, but there are sometimes exceptions.  This Olive Hairstreak spent close to five minutes exploring the onion flowers.  The Olive Hairstreak spring brood was quite successful this year.  The second brood is now coming on more strongly than I have seen in many years.

Early onion flowers are already producing seed pods.  I should have ample seed to increase my captive population of plants, as well as scatter some seed out into suitable wild sites.  It’s taken longer than I had originally thought, but I’m now becoming optimistic that this project could be successful.

Draba cuneifolia

For several years now, I have maintained a population of the uncommon winter annual, Draba cuneifolia, in a container filled with a substrate that superficially mimics that found in its natural habitat on the barrens. This artificially maintain colony has been thriving.

These interesting little plants have just begun to bloom. Previous year’s seed crops have allowed me to return a great quantity of seed to the barrens. Seed is always scattered in areas from which the original seed came.  The bounty of seeds from the container grown plants has far exceeded that which could have been expected from plants produced on the barrens. 

As with many captive plant populations, this one has refused to respect its defined boundaries and has dispatched its seed to produce new colonies.  I am now finding Draba cuneifolia growing along the concrete foundation of my barn…

from cracks in the decomposing concrete of the apron outside the barn door…

and even out of the drain holes of other containers.

In October 2014, I found some Draba cuneifolia seeds stuck in the folds at the bottom of my seed collecting sack. I scattered the seed in a garden bed that I am using for the production of Spider Milkweed, Asclepias viridis. Draba seeds need to go through a period of high temperature before they will break dormancy, something that apparently didn’t happen at the bottom of my seed sack. It wasn’t until November of the following year that I began to see Draba cuneifolia seedlings. The orange ribbons mark locations of the milkweed plants which will do most of their growing after the Draba has already set seed.

The Draba cuneifolia grow extremely well in the deep, fertile soil of the garden bed. Were I to discontinue removing competing plant growth from these beds, the Draba would not survive.

All of these plants are loaded with flower buds and will soon be in bloom.

We had three days in a row of extremely cold temperatures during a time when there was no snow cover on the ground. Several of the exposed Draba cuneifolia showed signs of freeze damage.

Those damaged plants survived, but as they grew, they abandoned their single rosette form. Growth from multiple points caused plants to take on the appearance of small shrubs with numerous branches growing in all directions.

Draba cuneifolia growing on the barrens also showed signs of cold weather damage. Both of these plants display dead leaves, but they are still growing. Unfortunately, life on the barrens is more stressful for the species and the plants do not produce the vigorous growth of those growing in the garden.

I enjoy seeing the genetic potential expressed by the plants growing in the garden, but it’s these tiny wild grown specimens that I admire most. They are poor competitors and can survive only where other plants fail. Life on the barrens is rough, but these little plants are tough enough to survive there.

Potato Dandelion Harvest and Redistribution

My container grown Potato Dandelions, Krigia dandelion, yielded a record crop of tubers this year.  The half pound of tubers contained in this cereal bowl all came from a pot with an eight inch inside diameter.  My calculations estimated six tubers produced for every square inch of soil surface.

Total harvest for the year was 1.2 pounds of tubers.  I calculated that the average tuber weight was 0.78 grams.  That means there were about 700 tubers produced this year.

Tuber size ranged from about one inch down to one tenth of an inch.  The larger tubers will sprout multiple shoots next spring, while the smaller will yield only one shoot each.

Into the eight inch pot, I planted five large tubers and four small.  This equals what I put into the pot last August, and that multiplied into nearly 300 in the course of a single growing season.  I hope these do as well.

I’ve dedicated a couple more containers to Potato Dandelion production.  This pot has a 23 inch inside diameter, giving it eight times the growing room of the smaller pot.  That means it has the potential of producing nearly four pounds of tubers.  I would find that truly remarkable.

As I did last year, I planted the extra tubers into suitable locations in the woods.   Since I had more tubers to work with than I had anticipated, I planted about half of the tubers in areas away from the planned ridge top.  I moved down the hill and began planting at the edge of the tree line just above the barrens openings.  I made scattered plantings from there on up to the ridge top.

I chose planting sites that had friable soil, had little competing plant growth, were away from major animal pathways, and had a high probability of receiving plenty of early spring sunlight.

Once a site was selected, I cleared away the surface litter in a 10-12 inch long swath across the slope.

I then used the pointed end of an old two prong weeding hoe to dig twin grooves about 2 inches deep.  Into the grooves I planted 16 to 20 tubers.  For those who might misconstrue the condition of the tool as a sign of neglect on my part, be advised that I found the hoe half buried in the yard about a year after we moved here.  A thick layer of concrete on the head and lower portion of the handle suggested that the tool had been used for mixing concrete prior to its disposal.  The tool is in much better shape now than it was the day I found it.

Next, I returned the removed soil and firmed it into place.

Finally, I replaced the original surface litter.  You can’t even tell that anything had been done here.

In the vicinity of the plants that performed so well after last year’s tuber planting, I planted three small blocks of tubers.  These blocks were located near easily identifiable features that will make it easy for me to monitor their progress.  Hopefully, next spring will begin with Potato Dandelion flowers scattered through the woods.

Blooming Season Potato Dandelions

Sunlight is a key factor in determining whether or not a Potato Dandelion, Krigia dandelion, will bloom.  Woodland populations receive much of their sunlight prior to emergence of leaves on the deciduous trees.  Even in mid-May, the tree leaves have not developed enough to completely block the sun.

Fallen leaves from previous years can also keep sunlight from reaching the developing plants.  Those plants that must push their way up through the leaf litter rarely bloom.  That’s one reason why I transplanted Krigia tubers into areas of sparse leaf litter.  Strong winds pushing over the ridge tops consistently push leaves away from certain areas.  It’s in these areas that the Potato Dandelions should prosper.  I should they could thrive if animals stopped eating them.  In this grouping of four plants, all have suffered some degree of damage from hungry plant predators.

This is the most common condition.  Leaves and flower stalks severely trimmed back.

This specimen lost nothing but a flower bud.  Since the flowers rarely produce any viable seed at Blue Jay Barrens, the loss of the flower does no harm to the plant.  As long as the plant is healthy, the roots will produce a nice collection of new tubers.

When I planted Potato Dandelion tubers into this location last summer, I placed them in groups of three or four.  This set of three plants represents the most successful grouping I could find this week.  All three have managed to grow without any predation.

The tuber planted here must have had exceptional vigor to produce three flower stalks.  The tubers produced from these three plants could easily result in 30 to 40 plants on this spot next year.

Judging by the amount of leaves being produced, the container bound Potato Dandelions are going to provide me with plenty of tubers to transplant to the woods later this summer.  These plants were caged a few weeks ago after some browsing animal ate all of the leaves.  The damage occurred prior to the development of flower buds, so there was no reduction in the number of blooms produced.

The original source of tubers for my container grown specimens was the ridgetop woodland at Blue Jay Barrens where the plants were found to be naturally growing.  By transplanting container grown tubers onto that same woodland ridge, I hope to expand the size of the population as insurance against some disaster destroying the original population.  I manage the plants and animals found naturally at Blue Jay Barrens and have made it a strict policy to not introduce any species from outside the property boundaries.  With luck, someday I’ll have clumps of these little beauties enhancing the entire 1500 feet of the ridge instead of just the current 100 feet.

Mid-Season Potato Dandelions

The container grown Potato Dandelions, Krigia dandelion, are growing so rapidly that their image changes daily.  As long as I employ methods to exclude predators from the container, the plants flourish.  The abundance of leaves provides energy for the production of flowers and underground tubers.  A single plant may produce a dozen or more tubers during the spring growing season.  At this rate of reproduction, it doesn’t take long to build up a large population.

I thought this would be a good time to check on the progress of Potato Dandelion plants growing from tubers planted last fall into this ridgetop site.  This most closely matches the site of the original Blue Jay Barrens population of the rare Potato Dandelion.

A combination of wind and rainfall runoff patterns create patches of bare ground in this area.  Plants growing in these bare spots receive enough sunlight to stimulate production of flowers.

Some of the plants are looking quite healthy.  All of this growth has arisen from a single bean sized tuber.

Other plants have suffered damage from foraging Wild Turkeys.  Turkeys also create patches of bare ground, but at a cost to the plants.

I originally planted some tubers at the base of this cedar.  Turkeys chose this location as a place to take dust baths, and created two large wallows.  What once looked similar to the area in the right foreground, is now devoid of plants.

Potato Dandelions at the original site struggle to put their leaves up through the leaf litter.

The extra effort necessary to push leaves up through the leaf litter is enough to cause these plants to fail to flower.  I will occasionally clear the fallen leaves from a small area and allow the plants to produce flowers.  It’s nice to see the plants bloom, but since the flowers don’t seem to produce any viable seed, the activity give little benefit to the population as a whole.  The non-flowering plants still produce many new tubers, so the population continues to expand.

There may be other populations of the plant at Blue Jay Barrens, but there is only a narrow window in the spring when the plants are easy to see and finding them is complicated by the presence of the White Trout Lily, Erythronium albidum.

White Trout Lily is probably the most abundant woodland spring flower growing in the uplands at Blue Jay Barrens.  The shape and color pattern of the young Trout Lily leaf is remarkably similar to that of the Potato Dandelion.  That’s the Trout Lily on the right.  With hundreds of Trout Lily leaves in view at any one time, it’s easy to see how a random Potato Dandelion leaf could escape notice.

As long as my container grown plants continue to produce plenty of tubers, I will transplant the excess into suitable locations.  It doesn’t look like I’m in danger of having a shortage.