How Water Travels Through a Plant
When we need to “Water” ourselves we take a drink towards the top of our stem, our mouth.
This water, sooner or later is then is eliminated, as if by gravity below the point of entry.
Plants, on the other hand, take a drink at the very bottom of their structure, their roots, and then, defying gravity, eliminate the excess at the very top of their structure, their leaves.
How is this journey accomplished?
Pathway of Water Through a Plant
- Water enters the plant through the root hairs.
- It is then conducted upward in the stem via the xylem.
- Water exits the plant through the stomata located on the leaves.
Osmosis is the process used for the water to enter the root hairs.
Cohesion-tension theory is believed to be the method that water is conducted upward via the xylem. Think of adjacent drops of water, which when their exterior barriers are broken, move & merge into one larger drop.
Transpiration is the process of water evaporating from the leaf.
Roots have microscopic root hairs to take up more water
Roots
At the root of it all…are the roots.
Roots are designed in different ways to anchor plants.
Their main purpose, however, is to gather from the soil the water & nutrients needed to sustain & grow the plant.
To do this the root is designed in a point called the apical meristem.
This apical meristem pushes through the soil in search of nourishment.
In order to increase the surface for absorption the root has microscopic root hairs that increase the surface several hundred times. By osmosis, these root hairs bring water into the root.
Osmosis is the process that allows water to pass through cell epidermal walls. Water molecules attempt to balance the amount of water pressure on either side of the wall. Once the water enters the root hairs the equalizing mechanism is shut down & the water can’t escape. It then moves from the root hairs to the roots via a process called turgor.
Stem
Water moves through the plant from roots to leaves through the xylem. Osmosis moves the water from the ground to the root systems & cell turgor moves the water through the xylem.
Cell turgor is what keeps the firmness in plants. With low turgor you get wilting. You want to keep all cells filled with water or the cells begin to die.
This is why you cut flowers under water to use in your flower arrangement.
To protect the cells from exploding with too much water as it moves from the roots to the xylem, the cell walls protect themselves by pushing the water out into the hollow tubular cells in the root’s center using a gentle pumping action called root pressure. This brings the water into the xylem, which now conducts the water upwards from the roots to the leaves.
Transpiration
Rhododendron leaves in winter will curl up to reduce the number of stomates on exposed surfaces to reduce the transpiration rate of water. In my garden the rhodi leaves curl when the temperature moves into the 20’s
Transpiration occurs in the leaves by way of the stomates usually located on the underside of the leaves. Water is vaporized through the stomates & is replaced by liquid water that has been delivered by the continuous flow upwards through the xylem system of roots, stems and leaves.
This transpirational pull is felt throughout the entire length of the plant.
In most plants about 98% of the water is lost through the transpired water vapor from under the leaves. A 48-ft tall Silver Maple is thought to transpire up to 58 gallons of water an hour.
You can perceive this on a hot summer day when sitting under a large shade tree & enjoying the cooling effects of the transpired water.
Stomates
Plants protect themselves from too much loss of moisture by closing the stomates in the underside of the leaves. Generally, stomates are open during the day & close in the night-time. In the winter when the ground freezes you can see the curled leaves of large leaved rhododendrons as they reduce the available surface of exposed stomates.
In preparation for winter and in times of drought, leaves will fall from the trees in a process called abscission further reducing the stomatic surfaces used for transpiration.
Cold Hardening
In winter, the deciduous trees have lost their leaves and water movement halts. If the water freezes in the cells, it ruptures the cell membranes. You can see this quickly in Colocasia AKA Elephant Ears after the first cold snap.
One way that winter-hardy plants survive is by a process of cold hardening, which uses sugars that function somewhat like antifreeze.
The pathways for water distribution are also modeled for nutrient distribution in the plants but that is worth another entire post.
Growing New Gardeners
How do we grow gardeners? We start them young. We intrigue them with our questions about what they’re seeing, what they’re hearing. We let their imaginations run rampant. We celebrate their dirty hands and knees and when they grow up they already love their favorite garden spots.
My grandson CJ taking a break from chasing dinosaurs in our woodland garden on April 26, 2006.
We pass on what our elders taught us that captured our fascination with the world around us. How did we come to appreciate the complexity of leaf edges and the critters crawling under our stumps and stones? We talked with them, we enjoyed the experience of learning and sharing. We made the garden the center of their invented stories, their imagined dinosaurs, the strolling around the paths that led to nowhere but really everywhere.
My Uncle Teddy passed down to me the mysterious and exciting world of nature and the gift he gave me keeps giving. As my grandson CJ completes his Eagle Scout project of creating a woodland path through a nature preserve dedicated to native plant species with the eradication invasive species, we see how we generationally share our knowledge and continue to contemplate our universe.
My grandson CJ Ahern sitting at one of his favorite spots in our woodland garden on April 29, 2018 just before he started his Eagle project to restore a neglected woodland area at an animal sanctuary in Seaford NY.
Trimming Hellebores. My First Gardening Task of the Spring
That first sunny warm day in February seduces me into my garden to begin my spring gardening tasks before the last snowstorms of winter reappear for a brief visit. It is a happy day for me each year when I reach for my Felco’s, put on my gardening gloves, pick up my rake and head out to reunite with my garden.
Hellebores remain evergreen and provide winter interest in my winter garden.
I always start by trimming the hellebores since the longer I wait the more complicated the job becomes. Those stalwart evergreen leaves that have decorated my garden all winter are by this time raggy, spotted and brownish. Hiding beneath them are the brand new buds of the Hellebore flowers just waiting to burst through heralding spring. I love uncovering their light deprived lime green growth and freeing them to bask in the sunshine.
Cutting the old leaves at this very early stage makes it less likely that I’ll damage the new growth. The old stems are long and thick at this time and easy to differentiate between the short almost stemless new growth. On the years that for one reason or another I wasn’t quick enough to do this early trimming, the job took twice as long as I had to carefully select between the old and new growth leaves. Not easy to do without accidentally cutting off a few buds. Full disclosure: When I do cut or damage a plant in my garden I reflexively find myself apologizing to it out loud…sigh…
Not to worry about uncovering the hellebores when inevitably another bout of winter arrives since these are very hardy plants in my zone 6 garden. When the weather turns cold again for the next few weeks of winter I enjoy watching spring emerge through the windows in my home. Those hellebores burst through with so much optimism.
After trimming the old leaves, the emerging flowers of the Hellebore are a great glimpse of optimism for the upcoming spring season.
What is the difference between Hardy Bulbs and Tender Bulbs?
Hardy bulbs are planted in the fall and will come up in the spring. The reason they are called hardy is that they can survive and actually need a period of cold in order to bloom in the spring or summer. Given a period of 2-4 months of chilling, (perhaps in the refrigerator?!?) many of these bulbs can be forced into blooming early for a nice break in the dark of winter.
Examples of Hardy Bulbs: Tulips, Narcissus & Daffodils, Lilium, Allium, Leucojum, Galanthus, Arisaema, Mertensia, Dicentra, Crocus, Iris, Colchicum, Erythronium, Fritillaria, Hemerocallis, Hyacinthoides, Muscari, Ornithogalum, Scilla, Anemone blanda
Tender bulbs are planted in the spring for summer blooming. They cannot withstand the winter and must be dug up and stored in a cool dry place. They’re not as easy to force. These bulbs respond more to daylight and to warmth to start their growth cycle. To give them a headstart I usually start my spring and summer bulbs indoors in the late winter so by the spring the plants will be more substantial in size.
Examples of Tender Bulbs: Amaryllis, Dahlias, Begonias, Colocasia, Alocasia, Canna, Ipomoea, Gladiolus, Hedychium
Interested in having these flowers all year long? Visit my online Art Shop and select from an assortment of flowers and gardens.
These double daffodils bloom in mid-spring in my garden. It wasn’t until I began to create this Artwork did I realize that these particular flowers are quite fragrant unlike many of the spring blooming varieties. This made for a nice addition to my enjoyment of creation!
My Garden My Muse My Inspiration
My muse is my garden. Other gardens as well, but my garden in particular. I move in it, feel it, and hear the breezes whisper through it. I watch the lighting during the day as it slides over and around the textured surfaces.
This azalea and tree peony combination bloom in my garden together every year. Their colors match perfectly and are so inspiring to me!
Lighting is so different on days with sun and with clouds. Lighting in the spring with the bright yellow-greens of optimistic new growth and lighting by the fall with ambers & tans of a lived life. Morning light offers tender ambiance while afternoon colors not only light the scene from a different direction, the colors are deeper and warmer.
My garden brings consciousness and meaning to me. It keeps me grounded. The ephemeral beauty of an unfertilized blossom studied up close with magnifiers and macro lenses is a representation of a miracle. The world of possibility. The beginning of a story I represent in my Art. I walk through my garden gathering ideas. Stories I want to tell. Suggested ideas I want to convey.
In my garden I spend time designing the landscape or I spend time closely and intimately with a singular specimen at a particular stage of growth. In my studio I may paint a vignette or a full landscape view of a part of the garden I’ve designed, or I may choose to paint a small portion of one flower that has moved me. The minute miracle. This is my work. Outdoors and indoors. These are the stories I tell. This is my Art. You can see more of my work in my online Art Shop.
These Fire Flame Peonies bloom in my garden each year in May at the same time as the color matching azalea.This and other pieces of my Art can be purchased in various sizes on canvas, fine art paper, metal and acrylic in my online Art Shop.
Planting Combinations – Peonies and Azaleas
There are some plants in my garden that just demand to be viewed together. In my front garden bed is a Fire Flame Tree Peony that for years has bloomed at the same time as a perfectly color matched azalea. Together they light up their niche in the world for a week or two each year if I’m lucky.
These Fire Flame Peonies blooming in my May garden along with the azalea inspired my original painting.
Keep the rain away from the peonies and the heat away from the azalea & I’ve got a perfect vignette. I love the way the focal points shift around my garden all year when either color takes prominence or form, as it does in winter.
I think of my garden as a theater production where spotlights guide your eyes around the action on stage.
If you want to extend the season of the colorful joy of these planting combinations you should consider buying one of my pieces of Art. Visit my Art Store to see your options. You won’t be disappointed!
Fire Flame Peony – Available in the Mary Ahern Art Store
What is a Corm and How Is It Propagated?
CORMS
Corms look a lot like bulbs on the outside but they are quite different. They have the same type of protective covering and a basal plate like the bulb does, but do not grow in layers.
Instead, the corm is the actual base for the flower stem and has a solid texture. As the flower grows, the corm actually shrivels as the nutrients are used up. Essentially the corm dies, but it does produce new corms right next to or above the dead corm. It has contractile roots that bring down the corms as they rise up to the surface of the soil which is why the flowers come back year after year. Depending on the type of flower, it may take a couple years to reach blooming size.
A corm does not have visible storage rings when cut in half. This distinguishes it from a true bulb.
Corms of a dormant colocasia (Elephant Ears) and a crocus in bloom.
CORM ROOTS
Many corms produce two different types of roots. Those growing from the bottom of the corm are normal fibrous roots, they are formed as the shoots grow, and are produced from the basal area at the bottom of the corm. The second type of roots are thicker layered roots that form as the new corms are growing, they are called contractile roots and they pull the corm deeper into the soil. They are produced in response to fluctuating soil temperatures and light levels. Once the corm is deep enough within the soil where the temperature is more uniform and there is no light, the contractile roots no longer grow and the corm is no longer pulled deeper into the soil.
PROPAGATING CORMS
The newly dug corms will have cormels that are pea size formed around the top of the old corm. The remains of the old corm will be directly beneath the newly formed corms. When the corm is cleaned up and the old stem removed, the growing point of the corm will be evident. The cormels can be saved and replanted in the back of the garden until they reach flowering size.
Examples of Hardy Corms – Crocus. Arisaema, Crocosmia, Liatris
Examples of Tender Corms: Gladiolus, Colocasia, Alocasia, Bananas (Musa), Ensete, Taro, Xanthosoma
Tunicate Bulbs
Tunicate bulbs are some of the most familiar bulbs we come in contact with both in and out of our gardens.
Many underground plant structures are generally named bulbs. A definition of a bulb is a plant that incorporates its entire life cycle in an underground storage unit. Technically true bulbs are compressed stems surrounded by fleshy leaves acting as food storage organs. They are in the Monocot family of plants.
Graphite Drawing of Onion and Garlic bulbs by Mary Ahern.
Bulbs can be further classified by looking at their various growth habits. Some of these “bulbs” are actually further classified as “true” bulbs, corms, tubers and rhizomes. Examples of these bulbs respectively are: narcissus, crocus, dahlia and canna.
True bulbs are represented by two classifications, tunicate and imbricate as represented by onions and lilies in that order.
Tunicate bulbs have a dry thin paperlike sheath surrounding them which helps to prevent them from drying and improves their storage capability. The basal base plate along with the tunicate sheath hold the bulb together. Roots emerge at the bottom of the basal plate.
We enjoy these bulbs both in the kitchen and in our gardens. Our cooking is enhanced by the addition of the tunicate bulbs of onions, garlic and shallots. The joyous colors in our early spring gardens are presented by our daffodils, tulips and hyacinths.
What are bulbs and how do they differ from corms, tubers and rhizomes?
The term “bulb” is used by most people to refer to plants that have underground, fleshy storage structures. Only some of the plants commonly called bulbs actually are bulbs. The general definition of a bulb is any plant that stores its complete life cycle in an underground storage structure. These underground storage structures store nutrient reserves to ensure the plants’ survival.
Tubers, rhizomes, corms, and bulbs actually all serve the same purpose, just in a different way. They are each a storage unit for food that gives the plant the energy it needs to grow, bloom and complete its lifecycle each and every year.
The energy is created and stored by the foliage’s photosynthesis. You’ve probably heard that it’s important not to cut back the foliage after the bloom has died. That is because the leaves need to have time to absorb energy for next year’s bloom. Each storage system takes differing amounts of time to perform this task. Examples would be Alliums and Daffodils.
Bulbs or bulb-like plants are usually perennials. They have a period of growth and flowering. This is followed by a period of dormancy where they die back to ground level at the end of each growing season.
As with perennials, there are bulbs that are hardy in our climate and others that must be overwintered as house plants or placed in dormant storage.
Bulbs can be broken down into five types of storage structures. These include: true bulbs, corms, (stem) tubers, tuberous roots and rhizomes.
“Leeks and Pearl Onions” a graphite drawing by the Artist Mary Ahern
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Daffodil Divisions and Classifications
Daffodils are classified using two parts of the flower. For the purpose of this description, the daffodil is divided into two regions, the perianth (petals) and corona (cup). In further classifying daffodils the perianth (petals) is described by identifying first the outside edge of the petal, then the middle, and lastly the inside part next to the corona. The information I am providing in this article is gleaned from two sources, The American Daffodil Society … Continue reading →
Anatomy and Propagation of a True Bulb
BULBS Bulbs (which are referred to as “true bulbs”) grow in layers, much like an onion. At the very center of the bulb is a miniature version of the flower itself. It is composed of a shortened stem covered with modified leaves called scales. Helping the bulb to stay together is something called a basal plate, which is a round, flat area that are the beginnings of the roots on the bottom of the bulb. … Continue reading →
A Regal Hosta – The Krossa Regal
This large vase-shaped hosta emerges slightly behind some of my other hostas such as ‘Blue Cadet’. This slug-resistant architectural specimen is a commanding presence in my perennial garden. Though planted in full sun with absolutely no sunburn effects, I plan to divide it in the fall and put a portion of it in the woodland near the Hamamelis. I think their V-shaped structure will echo each other offering a nice rhythmic change of scale and … Continue reading →
Heralding Hostas
There are so many stages of hostas that I enjoy seeing. None of them include slugs by the way. Having a shade garden I naturally grow many different cultivars of hostas. This particular one is named ‘Blue Cadet’ and was given to me years ago by my son Chris for Mother’s Day. Two Cadets and a Phlox subulata, I made out like a bandit! Each year I try to catch the hostas as they emerge … Continue reading →
Anemone coronaria in the Garden and in Art
My Garden and my Art go side by side. Both require me to make aesthetic judgments about composition, scale, color, texture and style. When I’m deciding where to plant the flowers I’ve hauled home on my endless trips to the nurseries it doesn’t seem that much different to me then when I’m deciding how to compose them on a two-dimensional surface. I think about what style I’m looking for, what colors will work together, whether … Continue reading →