It’s a sunny day in late February and that means I’m looking at seed catalogs and dreaming of new plants! Have you been plant shopping yet this year? Adding new plants and seeds to your garden creates new scents, textures, colors, and shapes and is the easiest way to increase biodiversity in your landscape!
As you begin revitalizing your garden space this spring, I want to bring some attention to invasive plants, a category of plants that should strike fear and dread in your heart! Okay, maybe that’s a bit dramatic, but truly this is a topic that everyone needs to learn more about.
Q. What is an invasive plant?
A. An invasive plant is a non-native, “alien” species that was introduced intentionally or by accident into the landscape and causes ecological and/or economic harm. These plants tend to be free from predators, parasites, and diseases that could help keep them in check. These plants reproduce rapidly with multiple methods (i.e. seeds, stolons, root cuttings, runners, etc.) and spread aggressively. They tend to be deer resistant or deer tolerant, a big reason why they are purchased and planted in landscapes. Below is a photo of purple loosestrife. Notice how it is creating a monoculture, a visual key that might mean the plant is “invasive.”
Invasive purple loosestrife (Lythrum salicaria). Photo: Richard Gardner, Bugwood.org
Did you know that some invasives are still for sale at nurseries, greenhouses, and in mail-order catalogs?
It’s true. Many of the plants on “watch lists” are still readily available to purchase. Japanese barberry is an invasive plant that is a very popular landscape plant still being widely planted today; however, research shows that black legged ticks have been found in areas with invasive barberry thickets because these non-native, invasive forest shrub thickets create ideal microclimates.
With the transition into the Fall season, I often find myself feeling a mixture of emotions; relief, that another growing season is coming to an end; sadness, that it went too fast; and excitement for what the next year will bring! I am sure that our animal friends also sense the need to prepare for the changing seasons and as such, over the last few days, I’ve been seeing some damage happening in my yard from an uninvited guest!
Holes were dug in the lawn recently. Photo: A. Bodkins
Can you guess what caused this digging of the grass? This occurred in two different areas of my lawn over the course of a week. I also noticed the exact same digging at my parents’ house in this same time period.
Well, if you guessed a skunk, you are correct! An Eastern Striped Skunk to be exact, which you can learn more about by visiting the Maryland Department of Natural Resources website. These native critters are fairly small with a lot of fluff and a long tail. Their most characteristic marking is their black body with a white stripe down the middle. They are also known for their smell!
Holes in the lawn from a skunk digging and searching for food. Photo: A. Bodkins
As you can probably tell from the photos, my yard is not something that I manage too closely, with a mixture of grass types and broadleaf plants, so I am not upset that the skunk was foraging for protein sources. I am hopeful that he/she is enjoying some insects, and hopefully consuming some pest larvae like Japanese beetle grubs and slugs.
We often discuss the benefits of creating a landscape that is rich in biodiversity and habitat for all creatures. So what do we do when we find ourselves inviting a stinky guest to dine on insects and other soil-dwelling critters? Well, for me and my family, we will use this as a teachable moment with our children and be sure that we are not leaving anything outside that would be attractive to our new friends. Things like pumpkins for fall decorating, pet foods (or livestock feed), bird seed/feeders, trash cans, or compost scraps can be unintended foods for skunks, which are in the weasel family. At this point, we do not need to take action as my husband has only seen our guest once and it was early in the morning, which is the normal time that he should be foraging. The skunk sighting was also what helped confirm my suspicion of what was digging in the lawn.
Remember that the skunk’s main form of defense is to “spray” a very foul-smelling liquid (butyl mercaptan) from special scent glands. Once they release their “perfume” it leaves them vulnerable with no tools for defense for a few days so that is the last thing that they want to do. They will give you a warning sign of stamping or kneading the ground. If you spy a skunk doing a handstand, you best be on the retreat though, as that is the position they use for releasing their spray!
Mole or vole tunnels may appear to look similar to this damage, as it’s hard to tell from the photo, but this damage was not raised as you see with mole and vole tunnels. Remember, moles eat insects only, but voles will eat plants.
Be a careful detective and look for signs of problems in the landscape, whether that is a pest, plant disease, or mammal. In our instance, we saw skunk scat and then also the actual visitor to confirm what was causing the damage to the lawn. If you need guidance on the management of a nuisance skunk, please check out the University of Maryland Extension website on skunks and never try to capture, pick up, or relocate a skunk without help from a professional.
Happy Autumn!
By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.
Alfalfa (a legume) with nasturtium growing at the edge of a high tunnel. Photo: A. Bodkins
There is a whole group of plants in the Leguminosae (a.k.a Fabaceae) plant family and are referred to as legumes, a word that many people may have heard but may not know the special details about. Have you ever heard that legumes make their own nitrogen or that they are plants that never need nitrogen fertilizer? Well, both those statements are true!
A cover crop of spring seeded oats is included on this slope with grass and trees. Photo: A. Bodkins
Healthy soil can sustain plant growth, prevent environmental damage, mitigate stormwater runoff, and help recharge and clean groundwater.
Soil type is probably not something that people consider when they move to a new property, so it reminds me of the statement “you get what you get and you don’t throw a fit”. However, it is no secret that soils are not all created equally in their ability to grow plants. To make matters worse, the soil is constantly being manipulated to accommodate our needs. When infrastructure like roads and buildings are constructed soil is moved and in many instances, there may not be any native soil profiles still intact on the property. Often a small layer of topsoil is put back onto the landscape after construction and regrading of the land, but there is no guarantee that it was the topsoil found there before construction began. Once the excavation is completed there is no going back. This article from Penn State Extension, Can Disturbed Soils Grow Healthy Landscape? is a great read. If you suspect that the soil you are planting vegetables into has been hauled in from another location, it is wise to get the soil tested for lead content. Some labs also test for heavy metals like arsenic (As), cadmium (Cd), and chromium (Cr), which can be found in soils on old industrial sites.
Soil is the gift that can keep giving, but there are some management practices that can help improve all soils. The physical, chemical and biological processes of soil are all interconnected. If you want to learn more about your own soil, I recommend the Kansas State publication that walks you through the steps to Estimate Soil Texture by Feel. Knowing the soil texture in your garden is one piece of the soil puzzle.
Soil organic matter increases water holding capacity, improves water infiltration, serves as a source of micro and macronutrients, and provides large particles for micro and macroorganisms to break down. Soils that are high in clay or sand can benefit from the addition of organic matter, which comes from anything that was once alive. Macro and microorganisms help to break down organic matter and release nutrients into the soil. There are many forms of organic matter that include compost, plant material, livestock waste, humus or leaf litter.
A cross-section of healthy soil. Photo: USDA
Cover crops are another way to improve your soil because they capture excess nutrients that are left over from the growing season and prevent the nutrients from becoming environmental pollutants. Cover crops also prevent soil erosion from wind and rain during the late fall, winter, and early spring seasons when weather is not appropriate for most vegetable or agricultural crops. Once cover crops are terminated they can be plowed into the soil and add organic matter. This is called green manure. I’ve found that in my own garden, cover crops can also help prevent weeds from growing. Some cover crops like forage radishes die and create natural pathways through the soil for water to flow.
Buckwheat that I planted as an early season spring crop to help reduce weed germination in my vegetable garden. I had planned to terminate it and plant a late crop of cucurbits, but changed my mind after it was growing so beautifully and I saw all the insects that were visiting it daily.
Other management practices to help your soil include regular soil testing to monitor any changes and keep the soil pH in the correct range for your desired plants. Limit soil compaction by keeping vehicles, equipment, and even people from walking through gardens, especially when the soil is wet. At the very least, I think the best practice for improving and keeping your soil healthy is to leave it alone as much as possible, keep it covered with plants that are not invasive, and let the natural processes of the Earth work together to benefit the soil.
By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.
This year, the University of Maryland Extension Master Gardener Grow It Eat It Program celebrates the resource that supports all life on earth – soil! Look for soil education programs offered by your local Master Gardener program, and visit the Home & Garden Information Center website for more information about soil health.
People often say you have to feed your plants, but in reality plants make their own food through the process of photosynthesis, which yields oxygen and glucose. Glucose is the food that plants use for energy and growth, they don’t need us to actually feed them. Since plants can make their own food, they are called autotrophs. The green pigments in plants, called chlorophyll, capture light energy from the sun. The process isn’t nearly as simple as I’ve described it.
Plants can further be divided into two classifications, C3 or C4, which is determined based on how efficiently the plant can photosynthesize and whether the plant has to go through the process of photorespiration, which is required for C3 plants. This makes C4 plants, like corn, sorghum and sugarcane more drought resistant because of the complex processes that occur within the plant at molecular levels. The majority of plants are C3 plants. For more information on this topic check out the article from University of Illinois, The difference between C3 and C4 plants.
So why do plants need a soil that is sufficient in macronutrients and micronutrients if that is not their food? Well, the short answer is that nutrients help plants grow and keep them healthy so that they can photosynthesize efficiently. As the plant mass increases, the plant leaf size/surface area increases, which allows the plant to capture more sunlight and turn it into more food.
You can check out the Home and Garden Information Center’s webpage about fertilizer to learn more about macronutrients and micronutrients. Macronutrients are those elements that the plant needs the most of to be healthy. Water provides hydrogen and oxygen. Carbon dioxide provides oxygen and carbon which are part of the required macronutrients for all plants. The remaining macronutrients are provided by soil (unless the plant is being grown hydroponically, of course). Plants can only take up or use nutrients that are dissolved in soil water. This is why it is so important to make sure that your soil gets sufficient water. Some plants are called heavy feeders and this is generally in relation to their need for larger amounts of the macronutrients, especially nitrogen. Some examples are tomatoes, everything in the cabbage family, and beets. The University of Maryland provides more information on fertilizing vegetables.
Tomatoes (left) and a colorful cauliflower harvest with nasturtiums (right). Photos: A. Bodkins
By providing an optimum growing environment, through correct amounts of light, moisture, and nutrients, the plant will have the best chance at reaching its full potential. As I eagerly wait for the first produce from my vegetable garden this season, I want to be sure that all my plants reach their full potential and produce a large amount of food for me and my family to enjoy this growing season.
Please comment below with what you are doing this year to ensure that your plants are healthy and happy and growing well. Do you test your soil every 3 years or whenever you are planting a garden in a new area? Do you research the plant needs (full sun, part sun, or shade) before planting? What questions do you have about managing soil fertility and nutrients?
By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.
This year, the University of Maryland Extension Master Gardener Grow It Eat It Program celebrates the resource that supports all life on earth – soil! Look for soil education programs offered by your local Master Gardener program, and visit the Home & Garden Information Center website for more information about soil health.
Well, the short answer from a soil nerd (please note soil nerd is not the same as a soil scientist or soil chemist) is that yes it really does matter! Have you ever done the experiment with boiling red cabbage leaves and used that as a pH indicator? It’s a fun science experiment but probably wouldn’t work for determining an accurate soil pH.
People do not always see the benefit of getting their soil tested; however, if you take a good comprehensive soil sample, the information that you get from the analysis is invaluable. Not only will the results keep you from over-applying nutrients, which has economic and environmental benefits, but also it will ensure that your plants have all that they need right at their root tips.
In my opinion, the most helpful piece of information gained from conducting a soil analysis is the soil pH. PH is a measure of hydrogen ion concentration and tells you how acidic or basic/alkaline the soil is. Most vegetable garden plants prefer a pH between 6-7; therefore, acidic soils need to be amended with calcium carbonate (limestone). Acidic soils are indicated with numbers below 6 on the pH scale which ranges from 0 to 14. Soils in the Eastern US are often acidic, but the natural pH will depend on parent material and other soil factors, such as how the soil has been managed, what plants are growing there, etc.
It should be noted that some plants actually prefer acidic soils, such as rhododendron, azaleas, and blueberries. Also, some plant diseases, such as scab in potatoes, are worse at a higher pH. Lowering soil pH (often done by adding sulfur) can take several months and may need to be a multi-step process. It is a great idea to test garden soils in the fall, so pH-altering amendments have time to do their job. Here is a great cheat sheet to help you understand what your soil analysis results mean.
Blueberry. Photo: C. CarignanTomato. Photo: A. BodkinsYellowing leaves may indicate a nutrient deficiency. Some soil nutrients may be unavailable to plants if the soil pH is not in the optimal range. Test your soil to find out the pH and nutrient content.
Another reason that pH is important is that it helps determine the availability of soil nutrients. Soil pH is linked to Cation Exchange Capacity (CEC), which is influenced by soil particle size and the type of parent material (rock). Clay soils will have a higher CEC (sites to hold onto nutrient ions) than sandy soils. CEC will be reported on most soil analyses. If the pH is not in the correct range, then many nutrients are not available to plants, even if you have applied ample nutrients. Thus, in order for the nutrients to support plant growth, it’s important to get that pH correct! This will provide both economic and environmental savings. Check out this link for a neat chart showing nutrients available and pH.
The third reason that it is important to check pH is because it can affect soil microorganisms, which are going to thrive at a near neutral level. If the pH is too high or too low you will see a decrease in the number and activity of good soil bacteria, fungus, and more that help to break down organic matter and do amazing other things in the soil profile. (For more details on this topic, download PDF – Soil Acidity Impacts Beneficial Soil Microorganisms, from Washington State University Extension.)
Common questions about soil pH
Can pH change from year to year?
Some forms of nutrients —commercial fertilizers, compost, composted animal waste (cow, horse, pig, chicken manure), organic matter, the weathering of rocks, and even rainfall can alter pH. Fertilizers, depending on the type used, will alter soil pH at different rates. Refer to this PDF – Fertilizers and Soil pH from the University of California.
Can I use a home soil Testing kit?
I normally steer people away from these types of kits, just because there are so many inaccuracies, especially, if the kits were not stored at the proper temperature and the directions are not followed correctly, then the results may not be 100% accurate.
What about electronic soil testing probes?
I don’t have first-hand experience with these probes. I am sure that they do have a level of accuracy; however, I cannot justify the upfront cost. For most gardeners, soil testing every 3 years is sufficient, so in my opinion, it is easier to just collect the sample and send it to a laboratory.
By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland, edited by Christa Carignan, Coordinator, Home & Garden Information Center, University of Maryland Extension. See more posts by Ashley and Christa.
This year, the University of Maryland Extension Master Gardener Grow It Eat It Program celebrates the resource that supports all life on earth – soil! Look for soil education programs offered by your local Master Gardener program, and visit the Home & Garden Information Center website for more information about soil health.
As a first-year college student studying horticulture (and later agronomy) I had no idea what I was in for when I signed up for that first Introduction to Soil Science course. Growing up, gardening and working on my family’s dairy farm, soil was something that we often talked about, mainly if it was wet or dry, rocky or smooth, and of course to stay out of the garden when it was wet; however, I really didn’t understand how important managing it was or how many different parts could be studied!
The technical definition of soil is the natural body composed of solids, liquids, gasses, and living matter that is capable of supporting plant life and has properties resulting from the five factors of soil formation. Wow! A mouthful of words, but a key point from this definition is the word NATURAL— soil is what covers the earth naturally and helps to absorb and disperse solar radiation and precipitation. It also provides an anchor for plant life. With harsh treatment, this living portion can be damaged and thus can take many years to build back. It is important to know too that healthy soils help to mitigate climate change as they store a huge amount of carbon in the form of carbon dioxide (CO2) and organic matter.
