|
Most of us think of tidy, green walls when someone mentions hedges, but there’s a lot more to them than that.  Hedges add structure to a front yard (Kate Russell) What are hedges? Generally speaking, hedges are shrubs or trees grown very closely together. People started planting hedges some 6,000 years ago. Before long, they began weaving dead twigs and branches into hedges to create impenetrable barriers that kept livestock in and predators out. This practice is called pleaching. Some of the hedgerows in Ireland and the United Kingdom are more than 700 years old. I’m sorry to say, but hedges will not keep deer out of your garden.  Sometimes a hedge can protect your home from a drunk driver (Kate Russell) Hedges can be massive, unruly walls of living plants, neatly trimmed parterre perimeters, or anything in between. Hedgerows muffle sounds, prevent erosion, and reduce flooding. They can be ornamental or edible and shaped to your heart’s delight. This topiary is a popular attraction at many public gardens and amusement parks.  Topiary in India's Thiruvananthapuram Botanical Garden (Vijayanrajapuram) CC BY-SA 4.0 Hedges harbor hundreds of other living things Hedges may look static, but there’s a lot going on inside. According to one journal, a single hedge can host more than 2,000 different plant and animal species in a single year. Another study found that Belgium’s hedges held a greater variety of species than their forests. This biodiversity occurs because hedges create their own microclimates. Hedges block and redirect wind. They shade and keep the soil moist. That moisture provides for a variety of insects and fungi. Those, in turn, attract parasites, pollinators, predators, and prey. Birds are also attracted to hedges. Those birds often eat insect pests. One Berkley study found that farmers saved $4,000 a year in insecticide costs for every 1,000 feet of hedgerow installed. Imagine saving $400 a year because of a 100-foot hedge.  Birds often nest in hedges so be careful when pruning (tommileew) Pixabay Hedges provide food and shelter. They act as migratory corridors in a day and age when safe havens can be difficult to come by. Did you know that bats and moths use hedgerows as flight paths? I didn’t either. Some of the insects attracted to hedges, including braconid wasps, honey bees, ichneumon wasps, and predatory beetles, are beneficial. Others, such as brown stink bugs and thrips, are pests. Hedges can also create the perfect conditions for diseases, such as sooty blotch and flyspeck. Hedge maintenance Hedges require regular pruning to stay attractive. In most cases, that pruning is done by shearing. Shearing cuts everything into uniform lines. This practice can lead to dead zones inside your hedge that occasionally need to be removed. This can give your hedge a pockmarked appearance. You can prevent this problem by investing some time in hand-pruning your hedge from the inside out.  Massive hedge at Mission San Juan Capistrano in California (Billy Hathorn) CC BY-SA 3.0 Hedges also benefit from an occasional hosing-off. This cuts down on the amount of dust and debris that collect on all those leaves. A dusty hedge is an open invitation to wooly aphids, mealybugs, mites, and whiteflies.
Choosing hedge plants Hedges can consist of a single plant species or many different species. Boxwood and privet are common hedge plants. They stay green year-round and respond relatively well to shearing. You can choose native plants for your hedge. Or, you can create a shorter, insectary hedgelike border with yarrow or sweet alyssum. Edible hedges are a little trickier. You can create a blueberry hedge, just be sure to select a variety that is evergreen. Raspberry and blackberry hedges are delicious, but you’ll have bare canes in winter. Rosemary makes a beautiful, fragrant edible hedge, though you’ll end up with more rosemary than you could use in fifteen lifetimes. The same is true for lavender, tarragon, and thyme. You can also create a hedge using espaliered fruit or nut trees. Citrus, hazelnuts, pineapple guava, and pomegranate are just a few of the edibles that lend themselves well to hedge-making. Hedges are important components of copycat gardens, fruit cocktail gardens, rain gardens, sensory gardens, soundscapes, and storybook gardens. Whatever your garden theme, it can probably benefit from a hedge. My apartment balcony is another story altogether. To some, mice are tiny, adorable creatures. To the rest of us, they are destructive, disease-carrying pests.  Mouse (Alexas_Fotos) Pixabay Mice are members of the Mus genus unless they happen to be deer or field mice (Peromyscus). There are several types of Mus mice, the most common being the house mouse. There are also white lab mice and mice sold as pets. Mice have followed us throughout history. We provide easy food sources and shelter, often against our will. Mice are intelligent, curious creatures. Mouse description Most of us recognize a mouse when we see one. Its pointed snout, cute little rounded ears, and naked tail are clear giveaways. Or are they? It ends up that the words mouse and rat are not taxonomically specific. In this case, size really does matter. In Ancient Roman times, rats and mice were differentiated by size, calling them mus maximus and mus minimus, respectively. Descended from an ancestor shared with lagomorphs (rabbits), these species went their separate ways several million years ago. All of them are highly prolific gnawers. Gnawers have some amazing teeth. The reason these animals keep gnawing on things is that their teeth grow continuously. In the photo below, you can see a single lower incisor tooth below the rabbit jaw from which it came. The tooth fits neatly into a tube in the jawbone, and it is always moving outward.  Rabbit jaw with one incisor removed (Kate Russell) Mouse or rat? One of the easiest ways to tell if you have a mouse or a rat today is to look at its nipples. Rats have six pairs of nipples. House mice have five. But who’s counting? Other differences include the larger ears and thinner tails of mice. Mice and rats are both excellent climbers and swimmers, but mice can jump surprisingly far, for their size. Mice and rats have poor eyesight but their senses of hearing and smell are excellent.
Mice build their nests in tiny pockets of darkness. Those pockets may be found in burrows or any number of neglected spaces in your yard or home. Mice may be small, but they can cause big problems. Problems caused by mice Mice may have impressive teeth, for their size, but those teeth are softer than a rat’s. Instead of chewing through concrete and aluminum, mice prefer softer materials, such as wires, irrigation bags, and plants. Mice chewing on electrical wires have been known to cause housefires. They can also create new openings in your ductwork and damage anything you have stored out of the way for safekeeping. It ends up “out of sight, out of mind” isn’t particularly safe for your treasured holiday decorations or mementos when mice are nearby. In the garden, these herbivores prefer fruits and grain for their food, but they will take whatever they find. Contrary to popular fiction, mice are not especially fond of cheese. [I imagine it gets stuck in their teeth.] Instead, they will strip your cereal grains, ravage your nectarines and persimmons, and make short work of your peas and beans. Look for tiny teeth marks on pods, fruits, and stems. They will also pull seedlings and small plants down from underneath to enjoy in relative safety, along with newly planted seeds. If your seeds and seedlings have been disappearing, mice may be the problem.  Field mouse on barley (Charlie Marshall) CC BY 2.0 Mice are also responsible for spreading diseases such as hantavirus. Hantavirus causes kidney damage and failure. The disease is spread through mouse urine and feces which are found everywhere mice go. No pun intended. Mouse management In my experience, a traditional mousetrap smeared with crunchy peanut butter is the best way to trap mice. You can add other nuts and seeds to the peanut butter mixture as an added attractant. One minute a mouse sees food. The next moment, its life is over. When your trap is successful, don some gloves and a mask, remove the mouse from the trap and place the mouse in a plastic bag before depositing it in the trash.  Mousetrap (PublicDomainPictures) Pixabay There are also electronic traps that electrocute its victims. Live capture traps can also be used, but those mice must be released somewhere else, potentially spreading disease into new areas and disrupting the delicate balances of life that exist there. As prolific as mice are, I opt for the kill trap method. Do not use poison or sticky traps. They are cruel. Sticky traps leave their victims to starve to death and poisons put pets, small children, birds of prey, and many other creatures at risk.
Small dogs and cats will go after mice, but only if they are left out all night, every night. In my opinion, the damage they may cause chasing a mouse outweighs the damage they prevent. Since cats tend to choose garden soil for their “business” and outdoor cats are more prone to injury and disease, I feel cats belong indoors. That’s just me. Tarantulas will also kill mice, but I don’t want one of those running around loose in my strawberry patch. How about you? Have you ever seen those big bags wrapped around the bases of young trees? They are irrigation bags. There are flattened versions used in garden beds, too. Those are called garden or watering mats.  Tree watering bags help young trees get a good start on life (Michael Trolove) CC BY-SA 2.0 A steady supply of readily available water is critical for young trees and other plants to establish new root systems. Water stress can kill a plant. If there’s not enough water, they usually shrivel up and die. If there’s too much water, fungal diseases, such as damping off, set in. Or, they may simply drown. Irrigation bags help prevent these problems. How irrigation bags work Irrigation bags and garden mats store water and release it slowly. They are handy if you are going to be away or if drought conditions exist. Irrigation bags and garden mats are tough UV-stable, tear-resistant tarp material. Some irrigation bags stand up against and get strapped to the trunks of saplings. Others are donut-shaped. Garden mats lay flat and provide spaces for plants to grow through. You simply fill the bags with water using a garden hose. Some irrigation bags have adjustable drainage holes. Benefits of irrigation bags Irrigation bags provide several benefits. A steady supply of water is only one. Irrigation bags can also stabilize soil temperatures, benefitting soil-dwelling worms and microbes that support your plant’s root system. Irrigation bags reduce erosion in sloped areas where water and soil might roll away. Irrigation bags can also serve as a weed barrier.  Zippered irrigation bag wraps around tree trunk (Caniceus) Pixabay Irrigation bags should be removed each winter and sanitized between uses.
The downside to irrigation bags Anything that comes into direct contact with a tree trunk or central plant stem for an extended period sets the stage for pest and disease problems. Insect pests, mice, and rats use irrigation bags and tree wraps as protection against predators and the elements. Here, they can gnaw, burrow, and procreate in relative safety, leading to bark breaches, infestation, and infection. As moisture stays close to a tree trunk or stem, fungal spores can take hold, leading to disease. If you use irrigation bags or something similar, be sure to check the integrity of your plant’s natural protections regularly. Irrigation bags are great for young trees, at first. For as long as all the roots are near the base, that’s where the water needs to be. As a tree grows, its root system extends out horizontally. [Picture a goblet on top of a dinner plate.] This provides stability as well as access to nutrients and water. If all the water stays at the base, the roots will be less likely to extend outward, making the tree more likely to fall over as it gets bigger. As a tree grows, irrigation rings at the drip line create a healthier environment and better stability. Soaker hoses do a pretty good job, too. Applying the same idea to other plants Irrigation bags and garden mats work much like self-watering planters. You fill them up and watering is done. These products aren’t particularly expensive, but there are some DIY on-the-cheap tricks you can do at home. You can use some of those plastic shipping bags or trash bags. Put them where you want them, fill them with water, being careful not to over-stress the material. Then start poking holes in the bottom until the desired flow rate is reached. These bags won’t hold nearly as much water, and I don’t know if there are any chemicals that might leach from those materials. I’ll leave that to you to research. Some people use layers of water-soaked towels. When roots grow upward into the towels, they become permanent parts of the landscape. You can also sacrifice a wheeled plastic trash can to act as a portable water source by poking a few holes in the bottom. Then wheel it to where water is needed, fill it with the hose, and close the lid. Watering done. There’s also the trick of filling a glass or plastic bottle with water, flipping it over, and inserting it into the soil. Easier said than done, in my experience, but it does work. Sometimes. Sometimes all the water flows out all at once, and sometimes it doesn’t. I don’t know why. The previous owner of my old house buried gallon milk jugs throughout the landscape for irrigating. She cut off the bottoms and buried them so that only the openings on top were exposed. It seemed very convenient at first. Then I realized that, unlike more durable pot irrigation, the plastic was degrading, and the space was filling up with soil, debris, and rocks, leaving very little room for water. I decided to remove them and fill the spaces with root-friendly, watering-storing soil. The plants seemed to like that plan. Irrigation bags and watering mats can save a lot of time, and provide plants with important water, but you can’t forget about them completely. Sun spiders are the stuff of legend, but they aren’t spiders. _1600.jpg) Male sun spider (JonRichfield) CC BY-SA 3.0 Also known as camel spiders, wind scorpions, and solifuges, these arachnids are kin to both spiders and scorpions, but they have their own order (Solifugae). There are more than 1,000 different sun spider species around the world. Large, fast, and secretive, many of these helpful predators prefer arid regions, but they are also found in scrub, grasslands, forests, and coastal areas. Their name comes to us from the Latin for “flees from the sun”, which is why these hunters are rarely seen. Sun spider description To hear people talk, you’d think that sun spiders were 12 feet long and ready to fill you with their venom. The truth is, they don’t have venom. What they do have are some monstrously large, curved pincer-like claws (chelicerae). And they move very quickly. Sun spider bodies can measure ½” to 3” long. If you add the legs, they can reach 6”. Okay, a 6” spider-like creature would freak me out, too. Most North American sun spiders are less than one inch long, legs included.  Arizona sun spider just over 3 inches long (Braboowi) CC BY-SA 3.0 Like other arachnids, sun spiders have eight legs, two body parts (a prosoma and an abdomen), and pedipalps at the mouth. They do not have fangs, venom, or spinnerets. They do not spin webs or have a distinct tube (pedicel) between the two major body parts.
Beneficial sun spiders Sun spiders are nocturnal or diurnal hunters. They capture many different insects and small animals, preferring termites, darkling beetles, and other ground-dwelling arthropods. Sun spiders have also been known to eat birds, rodents, small lizards, and snakes. After killing their prey, sun spiders cut their food into pieces, liquify it, and drink it. Generally speaking, these spiders are no danger to us, though they can inflict a painful bite. In a laboratory, one female sun spider ate more than 100 flies in an effort to fatten herself up before egg-laying began. I like that about her. Sun spiders live in relatively permanent burrows. Females lay 50-200 eggs each year and then guard those eggs until they hatch. Newborn sun spiders are translucent. As they mature, they become reddish-brown. Sun spider myths The size, speed, and scary appearance of sun spiders have given rise to many [false] legends:
Myths aside, these hidden hunters are beneficial. Have you ever seen one in your garden? We’ve probably all lost seedlings to damping off disease. Nascent stems, healthy only the day before, suddenly appear pinched and broken, never to recover. When lesions appear further down the stem at the soil line, it is called collar rot.  Collar rot of apple tree (William M. Brown Jr., Bugwood.org) CC BY 3.0 Collar rot gets its name because of the lesions that form a collar around where the root system meets the stem. In embryonic plants, this area between the first root (radicle) and the first stem (hypocotyl) is called the collet. In more mature plants, this area is called the crown. Vulnerable stems and seedlings In the case of both damping off disease and collar rot, pathogens enter delicate new stems as they emerge from the earth, scratched by soil particles. These tiny wounds provide points of entry. Insect and herbivore feeding, garden tools, and rubbing due to overcrowding and improper pruning can also create these wounds. Wounds heal quickly, but sometimes pathogens get in. When they do, problems begin.  Alternaria black mold on pepper plants (Virginia Tech Learning Resources Center, VPISU, Bugwood.org) CC BY 3.0 Collar rot symptoms As fungi, bacteria, and other pathogens enter a plant, lesions start forming in a band, or collar, around the lower portion of the main stem. At the same time, vascular bundles become blocked and the disease-causing agents begin multiplying. Collar rot pathogens Collar rot looks similar to damping off disease because the same pathogen may be responsible. Collar rot can also be a symptom of several other infections. Trees infected with fireblight tend to be more susceptible to collar rot, but we don’t know why. As you can see, collar rot isn’t a specific disease. Instead, it is a symptom of attack by several different pathogens:
 Sclerotial blight of Swiss chard (Scot Nelson) Public Domain Collar rot prevention
Collar rot occurs in gardens and containers where the soil is infected. You can prevent the infections that cause collar rot with these tips:
I hope collar rot never occurs in your garden.
Abundant oxygen Oxygen is the third most abundant element in the universe. We now have a lot of it here on Earth, though the numbers can vary. Oxygen currently makes up more than 20% of our atmosphere. You may be surprised to learn, as I was, that oxygen, in the form of oxides, makes up nearly half of the Earth’s crust and nearly 90% of our oceans. Oxides are molecules made up of at least one oxygen atom which is bound to some other element.  Oxides, such as iron oxide or rust, form when oxygen combines with other elements (Paulnasca) CC BY 2.0 Binding is common in the world of oxygen (O). Two oxygen atoms tied together form the dioxygen (O2) found in our atmosphere. Add two hydrogen atoms to an oxygen atom and we get water (H20). Add two oxygen atoms to a carbon atom and you get carbon dioxide (CO2). But I digress. Plant respiration We’ve all heard how trees provide us with oxygen, but that’s not as true as we once believed. We now know that 50-80% of the oxygen we breathe comes from marine plants and plant-like organisms. So the majority of our oxygen comes from plankton. Also, plants only produce oxygen when they are performing photosynthesis. At night, plants are using rather than producing, oxygen. Plant respiration takes place through leaves, tree roots, outer stem cells, and root hairs. And respiration is more than just breathing. Respiration refers to any process within a living thing that uses a gas exchange to generate or release energy. When a plant is actively producing energy from light, carbon dioxide is inhaled and converted into sugar, and oxygen is exhaled. This is called the Krebs Cycle. Oxygen molecules are also used to break the sugars into usable bits. This is called oxidization. Some plants reduce the amount of oxygen available to neighboring plants using tannins in a type of chemical warfare known as allelopathy. Oxygen and decomposition If your compost pile doesn’t have enough oxygen present, it will turn into a stinky, rotten mess, or nothing will happen at all. The microorganisms responsible for decomposition breathe air and drink water just as we do. This is why it is important to flip and moisten your compost pile regularly for it to break down into usable bits for your plants. Oxygen in the soil Dissolved oxygen in the soil is critical for healthy plants. Soil that contains a lot of dissolved oxygen tends to produce plants with significantly larger root systems. Larger root systems mean healthier, more productive plants. Pumping oxygen into your garden soil probably isn’t on your to-do list. But there are two things you can do to increase the amount of oxygen and other helpful gases in your soil: improve drainage and reduce soil compaction.  Compacted soil has less room for air and water (Kate Russell) I hope that you will breathe deeply and enjoy the changing scents of your garden as we move through the seasons. And remember to give that compost pile a turn.
Underneath the cover of growing plants, leaf litter, and crawling insects is a layer of dark, nutrient-rich topsoil. Below that is something else entirely.  Flooding exposes lighter colored subsoil (USDAgov) CC BY 2.0 We are all familiar with the importance of topsoil and how it helps our plants grow, but the subsoil layer is also very important to plant health. Do you know what is in yours? What is in subsoil? Subsoil is mainly weathered rocks and clay. It contains little if any organic matter, so it is often lighter in color than the soil above it. But this doesn’t mean it has nothing to offer your plants. This is where gypsum, silica, and clay particles filter down and collect. The clay found in subsoil has been used throughout human history to make adobe. It is also the material of choice in wattle and daub fencing. But clay isn’t the only thing that collects in the subsoil. Aluminum, calcium, iron, magnesium, and other nutrients accumulate in the subsoil, as well. If there is a lot of iron present, the subsoil layer will have a more brown or reddish tint. Because these minerals are often moved by percolating or illuviated water, it is also called the illuvial horizon. The subsoil layer often has a distinct soil structure from the layers above and below.  Subsoil layer (David Brinicombe) CC BY-SA 2.0 How do plants use subsoil? All of a plant’s early growth takes place in the topsoil layer, where nutrients, helpful microorganisms, and water are in abundance in most cases. After that initial growth, many roots move into the subsoil. The subsoil provides anchorage, food, and water. Tucked into the spaces between the minerals and tiny rocks that make up subsoil are pockets of water and mineral nutrients. Water held in the subsoil is protected from evaporation. When topsoil is dry, water can still be found in subsoil. In the photos below, each block represents one square foot of soil.
Subsoil, erosion, and compaction
Rototilling, construction, and heavy traffic can strip away topsoil, exposing the subsoil. Because subsoil does not contain the same organic matter, microorganisms, and root systems that hold topsoil in place, erosion occurs at a much higher rate. Those actions can also lead to the creation of a hardpan layer that blocks air, water, and roots almost completely. Compacted soil interferes with plant growth, drainage, and overall soil health. It is often corrected by aeration and deep-rooted cover crops. Compacted subsoil can be detrimental to plant health for many years. One study found that a compacted subsoil layer affected plant growth for nearly 20 years after the compaction occurred. Correcting subsoil compaction is expensive and difficult. Unfortunately, it is also very common in gardens due to home construction. This is why we are all required to conduct perc tests when buying a home. If water can’t percolate down and away, your home might find itself down the river after a particularly bad rain. [In the past, contaminated soil was used to create an artificial subsoil layer for home construction. Luckily, those days are behind us.] You can protect your soil and plants by being judicious about rototilling, creating paths, and avoiding walking on wet soil. Subsoil can be converted to topsoil by adding substantial amounts of aged manure, compost, green manure, and time. What’s in your subsoil? If you have a soil sampling tool, you can use that to collect a sample of both the topsoil and subsoil layers. Or, you can use a trowel or shovel. You will need to dig down a foot or two. Look for changes in both color and texture. You can take a sample of subsoil and send it out to a lab for testing, or you can test its texture for yourself. You can also test your subsoil’s permeability at home. These home tests won’t tell you which nutrients are present, however. Take a look at your subsoil and tell us what you find in the comments. Extra points for fossils and treasures! |
Welcome!You can grow a surprising amount of food in your own yard. Ask me how! To help The Daily Garden grow, you may see affiliate ads sprouting up in various places.
You can also get my book, Stop Wasting Your Yard!  Index
All
Archives
September 2024
|
RSS Feed