Author:Ashley

How to Navigate the Internet When Searching for Solutions to Home Horticulture Problems

Maryland Grows1 Comment
Photo: C. Carignan, University of Maryland Extension

All gardeners have challenges in their landscapes and at some point you may turn to the internet for answers. While the internet is a great tool for researching home gardening questions, it can come with challenges. These tips are meant to help guide you through successful internet searches. Remember you can always reach out to your local University of Maryland Extension office or use Ask Extension to get answers to all your gardening questions.

The first step when I begin research is to outline the goals for what I’m trying to figure out. Are you just curious? Is the plant or pest something that you want to try and control? Are you looking for a new plant to add to your garden or landscape? Maybe you are looking for the answers to multiple questions.

Two tips for searching the internet for garden answers

Tip 1: Be specific and always add the word “Extension” or “search term + Extension + your state” to the search phrase. This is helpful for finding the best science- and research- based information. This tip can help eliminate products or services. If you know your state’s Land Grant Universities, add those names to the search box, especially when searching for garden/natural resources related issues. 

For example, if you want to research “spring blooming purple trees” you might search those words and end up frustrated without any specific answers.

screenshot of a web search for purple flowering trees
Search results for spring blooming purple trees

If you add the word(s) Extension, or UMD Extension as in the following example, you will get results from University of Maryland:

a screenshot of a web search for blooming trees + UMD Extension brings up content from the University of Maryland
A search for spring blooming purple trees with “UMD Extension” added brings up content from the Univeresity of Maryland.

Tip 2: Focus on something unique about the specimen— whether it be a plant, insect, flower, seed, etc., such as colors, patterns, or antennae on an insect. Odd characteristics pinpoint search results and make searching easier and faster.

Example: If you just search the word “beetle” with no descriptor words, you will get just that, a general page about beetles.

a screenshot of an internet search for beetles pulls up a general page from the Smithsonian about all beetles in general
Search results are general if you use a broad term like “beetles”.

If you add more detail like color, the results begin to get more refined:

screenshot of a web search for black beetles pulls up results like larder beetle and ground beetle
Information about black beetles from university sources

Extra details with an oddity highlighted will get you even more specific results:

screenshotof a web search for beetles with long antennae
A more descriptive search about beetles with long antennae and using “+ Extension” brings up more specific results from university sources.

How to be a good garden detective?

Often, this goes back to being thorough and paying attention. Our landscapes and gardens often “whisper” and do not scream. If we ignore small signs, symptoms, and clues, that is when it appears that the problem happened overnight.  

Plant identification is something that many people struggle with— maybe it’s a weed, maybe a plant with an invasive tendency, or maybe it’s a plant that is bringing something positive to your landscape/natural area. Knowing exactly what the plant is is very important. We could spend a lot of time and energy reviewing botany but these tips are meant to help you build good searching habits.

a mass of small plants covering a drainage ditch
Non-native watercress (Nasturtium officinale) growing in a spring-fed drainage ditch. Photo: A. Bodkins

Next month, we will explore different plant apps for your mobile device, but ultimately with or without a plant app, correct plant identification often relies on mature plants that are intact/complete– including the reproductive structures (flowers, fruits, or seeds). Consider the photo above. There are plenty of healthy specimen plants. Questions you can use to help guide your internet searching are:

  1. What environment is the plant growing in — sun, shade, wet, dry, etc.? 
  2. Is it an isolated specimen or are there several specimens of the same plant? Is it prolific and making a monoculture, as in the photo above? 
  3. Is there a flower on the plant? Flowers can be very helpful for figuring out the correct plant ID. Some keys and guides focus primarily on flowers to identify plants. 
  4. Is the plant mature? Are the leaves complete? Remember there are simple and compound leaves. Always look for the petiole, which is the structure/stalk that connects the leaf to the stem. Leaflets of a compound leaf will not have individual petioles. 
  5. Are there seeds/fruits/nuts? Underground plant structures, like rhizomes, bulbs, or crowns?   
  6. Plant ID apps can be helpful but might not be 100% correct all the time. More on this topic next month. 

Here is another view of the drainage area full of watercress. No other plants are green yet in this photo, which is another unique fact that you could potentially use in an internet search. Often non-native plants will break dormancy and begin to grow sooner which can indicate that they do not belong in this location, as is the case here. 

another view of a drainage ditch - the water surface is covered with small green plants
A drainage ditch filled with non-native watercress (Nasturtium officinale) Photo: A. Bodkins

For insect or arthropod identification:

  1.  What is the type of damage you’re seeing (chewed holes or tiny dots that indicate piercing/sucking?)
  2. How many legs? 
  3. Is it an adult insect? 
  4. Are there many others present or just one specimen? 
  5. Is there more than one type of insect? Sometimes the most obvious is not the actual problem. 
  6. Are there visible wings? How many?
  7. Interesting colors, patterns, etc.?

Tips for collecting specimens for photos or to take to your local Extension office:

  1. Healthy and complete specimens are very important. 
  2. Photos are a great addition to a specimen, but they must be in focus. 
  3. Keep the specimen in the best condition that is possible. Digging the entire plant is a best practice, then wrap in a wet paper towel or newspaper and place in a plastic bag/container. Keeping the plants cool until you can get them to your Extension office or plant clinic is also helpful. If there is just one specimen and you are on public property, there is always a chance that it is exotic or protected. Please consider just taking photos in these instances. 
  4. Always note any flowers/fruiting structures. 
  5. Advice and suggestions from Extension professionals can only be as good as the information provided— please do your part to submit appropriate photos/specimens. 

Taking photos: 

  1. Close up and complete specimens are needed. 
  2. If there are flowers or fruits, always get a photo.
  3. Photos of the environment are helpful to gain a better understanding of the situation. 

Remember, correct identification— whether plant, insect, tree, plant disease, etc.— is the key to managing landscapes sustainably! The most frustrating part of searching the internet is that you don’t know what you don’t know— so asking a specific question about a mystery is hard. The internet is full of wonderful information, but it also has misinformation especially when taken out of context and information may be incorrect for your specific location or growing zone. Once you begin applying some of the above tips you can streamline your search experience and have better success with finding answers from reputable sources.

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.

Getting Rid of Invasive Plants: Solarization, Smothering, Repeated Cutting, Herbicides?

Maryland Grows1 Comment
Asian honeysuckle has white flowers
Invasive Asian honeysuckle (Lonicera sp.). Photo: Rachel J. Rhodes, UME

Eliminating unwanted plants is often one of the most challenging chores that gardeners face. Not introducing invasive plants is the fastest and most economical way to make a positive impact, as once invasive plants are introduced to your garden, it can take many years to eliminate these invaders from your landscape. 

Invasive plants propagate and spread by many different methods, which makes controlling them difficult and different for each species. Please learn feasible control tactics provided by land-grant universities or Extension factsheets/webpages before starting. Fact-based research is the absolute first step in getting ahead of plant invaders. Often invasive plants cannot be controlled 100% in just one growing season, but preventing the plant from making seeds or spreading is better than doing nothing at all.

Questions to guide your research: 

  1. Get proper plant identification! Use Ask Extension, Local Extension Professionals, and Master Gardener Plant Clinics. Smartphone plant ID apps can give you some idea, but you should follow up and confirm the correct identification. Apps may be limited by photo quality and geographic area.
    1. Is the plant a woody perennial, herbaceous perennial, or annual? 
    2. Has the plant been a problem for several years in your landscape, or is it a relatively new concern? 
  2. You must know how it is reproducing/spreading in your particular situation. For example, if the plant reproduces from stem/root cuttings, the last action you want to take is to mow/weed-eat/till the roots, which would cause the plant to produce hundreds of new plants.  
  3. If controlling 100% is not a feasible option, determine how you can prevent the plants from spreading or allowing them to get stronger. 
  4. If you have an invasive plant in your landscape and you really enjoy it, learn how to prevent it from spreading. For example, the spread of some plants can be prevented by removing flowers/viable seeds so that wildlife does not consume and spread them, or so that wind/rain does not blow away the seeds. 
  5. Always include “MD Extension” with internet search engines to be sure that identification and control tactics specific to Maryland are being filtered to the top of your results.
purple and blue berries of invasive porcelainberry vines
Invasive porcelain-berry vines (Ampelopsis glandulosa var. brevipedunculata). Photo: Rachel J. Rhodes, UME

Three basic control options are categorized below.

Mechanical control

Mechanical control options are often the first step that people take in controlling unwanted plants; however, these are by far the most physically demanding and often lead to a high level of site disturbance. Examples of mechanical control are:

  1. Pulling  and digging.
  2. Suffocation or smothering with landscape fabric, mulch, cardboard, multiple layers of newspaper, anything to block the sunlight and prevent the plant from growing.
  3. Solarization: laying plastic over the plants to “cook” live plants and viable seeds with the heat that builds up underneath. 
  4. Cutting, repeated cutting, or mowing in hopes of weakening stored nutrients so that the plants can not regenerate. This is also done to remove the flowering/seed structures. 

Biological control 

Biological control options utilize something else that is alive—insects, fungi, grazing livestock animals, etc. More and more of these options are being explored; however, sometimes the control agent may be 100% specific to the problem plant, or sometimes it may be able to feed on other plants too, which is the case with the Kudzu bug.  

Kudzu bug (Megacopta cribraria). Photo: Russ Ottens, University of Georgia, Bugwood.org

Chemical control through herbicide application

  1. Foliar Applications
  2. Cut Stem or “Hack and Squirt” Treatments

Herbicides are a management tool that may be considered when other control measures have not been successful. Sometimes this control option provides the least amount of physical labor, low soil disturbance, and is more effective than other options. Pesticides can be overwhelming and intimidating, with misinformation and inaccurate “facts” being shared. If you would like to learn more about “mode of action” and how different herbicides are classified, check out this Herbicide Mode of Action link from Purdue.

A few questions that might help you determine if it’s time to explore herbicides as an option. 

  1. Have you tried mechanical or physical control options without success? 
  2. Would one application of herbicide save the soil on the site from being excavated, dug, or destroyed?  
  3. Always use the most appropriate chemical control option by finding the plant that you want to control on the product label and following the application instructions carefully.
  4. Remember, with any pesticide (herbicide, insecticide, fungicide, rodenticide, etc.), the Label is the LAW! This is true even with organic pesticides. 
  5. The Environmental Protection Agency (EPA) is charged with approving, analyzing, and standing behind pesticides. Before approval, these herbicides are tested and labeled for use with specific instructions to minimize negative risk to yourself and the environment. Always use in accordance with the label and keep good records.
    1. Herbicides that are commercially available to purchase have been tested to know the recommended rates and residual activity in soils and on micro/macro organisms. There are a lot of unknowns with homemade solutions, so homemade “remedies” are not recommended.
Invasive winged burning bush (Euonymus alatus). Photo: Rachel J. Rhodes, UME

Disposal of invasive plants

The last step in controlling invasive plants is proper disposal. Leftover plant materials can lead to potential accidental new infestations.

Proper disposal guidance: 

  1. Burn– If your county/city allows the burning of yard debris, be sure to follow all safety regulations and restrictions and do not breathe the smoke.
  2. Pile– Fully dead/dried woody material that does not have seeds/fruits and is not covered in soil (which could allow it to sprout roots) can provide great nesting and shelter sites for wildlife- Read “The Value of a Pile of Sticks in Your Yard or Landscape”. 
  3. Dry or expose debris to intense heat– place debris in a black trash bag and let it “cook” for several weeks out in the hot sun, this will ensure that there are no viable seeds in the debris and all moisture is removed so that nothing can sprout. You can then add this to compost piles or dispose of it as you would “normal” landscape trimmings.
  4. Check with your county/city government to find out if invasive plants should go in your yard waste or regular trash.
English ivy (Hedera helix)
Heavenly bamboo (Nandina domestica)
Yellow flag iris (Iris pseudacorus)

Let the particular plant that you are trying to control guide your management plan, and research the plant before you begin. Start control strategies on a small scale to see what works best and remember that many of the characteristics that led people to begin planting these invasives are the exact reasons that they are hard to control— some examples: wildlife resistance, good at spreading, breaking dormancy before natives early in the season. Also, keep in mind that many invasive species are a long-term fight and will require perseverance and, for best results, will require the use of different control tactics. 

Lastly, once you successfully control the problem species, have a clear plan of what you will do with this space in your landscape. Installing new plants or keeping the area mulched will help prevent soil erosion or new infestations of weeds. Here is a list of recommended native plants for Maryland. 

Additional resources: 

Removing Invasive Plants and Planting Natives in Maryland – University of Maryland Extension

(PDF) Managing Invasive Plants: Methods of Control – New England Wildflower Society

(PDF) Guidelines for Disposal of Terrestrial Invasive Plants – University of Connecticut

Everyone can help in the fight against invasive plants! Check the University of Maryland Extension website for an Introduction to Invasive Plants in Maryland and more information on how to reduce them. The absolute best way is to just never plant or introduce them into your landscape. 

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.

What is Low-Till Gardening?

Maryland Grows1 Comment

In today’s post, I am going to focus on how to embrace low-till gardening systems, but first a quick refresher on soil.

The importance of soil

  1. Soil is a living and complex natural covering of the Earth. 
  2. Soil acts as a sponge to absorb water, nutrients, pollutants, and carbon. 
  3. Many aspects of soil cannot be changed, but properties can be managed to provide the elements needed to grow desired plants and it is the pillar of plant life in your landscape/ecosystem.
    1. Chemical, physical, and biological components make up the living soil. 
    2. Soil scientists are only beginning to understand the complex biological systems and how important they are to overall soil health.
  4. Topsoil is the usable portion for gardeners. Thus, all management techniques should aim to protect and enhance this valuable layer.
a row of plants in a freshly tilled garden
What you might see in a traditional in-ground garden with soil tilled in between the rows of desired plants. Image by Nadezhda56 from Pixabay

Pros and cons of tilling garden soil

In-ground gardening techniques have long been the method of vegetable gardening used in large-scale production. This system focuses on the mechanical tilling of a section of the earth. This soil is prepared and then seeds or transplants are placed in rows. In between these rows of plants is the walkway, which is either tilled at regular intervals or mulched to prevent weeds from growing. This technique works well but results in high levels of soil disturbance. Mechanical tillers require the use of a motor or a large amount of physical labor/exertion if done by hand. Once the soil is tilled, it is more likely to suffer from soil compaction. 

100% no-till gardening options

For alternative gardening methods that are 100% no-till, learn more by visiting these links:

Growing in Containers– University of Maryland Extension

Raised Beds– University of Maryland Extension

Lasagna Gardening or Sheet Mulching– Oregon State University Extension

Although tilling is the easiest and fastest way to create new planting areas and is also used as a weed control option, mechanical tilling of the soil (especially multiple times throughout the season) breaks down its structure and can reduce soil quality.

Negative effects of repeated mechanical tillage

Repeated tillage:

  1. Breaks down organic matter. The more often you are churning the soil the more the natural structure can be degraded and compacted. It disturbs natural pathways for water flow and for soil macro- and microorganisms. 
  2. Reduces soil stability by breaking apart aggregates.
  3. Exposes rocks and deeper layers of soil that are less developed.
  4. Exposes the seed bank of the soil to light and allows new weed seeds to germinate.  
an an exapleof a no-till garden with grassy paths between plantings
Image by Stéphane CHADOURNE from Pixabay

Differences between conventional and low-till systems

Low-till gardening systems often look different than traditional gardening systems. Low-till management techniques focus more on installing permanent pathways that are not disturbed yearly. These pathways may be outlined with stones or other permanent items. In the actual planting bed, low tilling is done with a handheld tool to create the planting space. Often these tilled areas would be smaller in size. 

Implement these practices slowly and expand as you have success. 

  1. Use a broadfork to loosen the topsoil, but do not dig deeper than necessary. This allows the natural pathways made by micro- and macroorganisms (earthworm tunnels) and plant roots to stay intact. 
  2. Keep the soil covered. Use mulch to prevent erosion. Mulch sourced from your landscape such as pine needles, grass clippings, clean straw, newspaper, cardboard, etc. can be used.
    1. Mother Nature always wants the soil to be covered. If you disturb the soil and do not cover it with mulch or other weed barrier, plants, or seeds, then weeds will grow. Wind and rain can quickly dissipate topsoil— replacing one inch of natural topsoil can take 500-1000 years! If the soil is covered it should not be as easy to wash or blow away.
    2. Add organic matter– whatever you have readily available. Mushroom compost, bagged cow manure, homemade compost, leaves, grass clippings, kitchen waste, etc. 
    3. Plant crops (cover crops, green manure) that will be cut down and left to decompose naturally in the soil or lightly turned in with a broadfork.
      1. Comfrey (Symphytum officinale) and other plants can provide large amounts of nutrients when used as mulch.
  3. Fertilize and amend the soil based on analysis results. Test your soil every 3 years.
    1. Add fertilizer sources through amendments.
  4. Till or disturb the soil as close to planting time as possible. This helps to minimize the time when no plant roots are helping to stabilize the soil. 

More details on improving soil structure can be found in the blog post:  How Can You Improve Your Soil?

bean plants growing in a no-till garden
Malabar spinach growing with corn. Example of companion planting in a no-till garden. Image by MAURÍCIO UCHÔA Bruttos from Pixabay

More on low-till gardens

Low-till is part of some permaculture practices. Permaculture practices have a goal of creating “permanent” growing spaces that utilize natural self-sustaining systems. Some of these permaculture practices can be adapted and used in our landscapes, especially those that include native plant areas, perennial fruits, and herbs. Other terms that incorporate these ideas and principles are food forests or forest gardening.

Tillage is a good tool, just remember to use it at the right time and for the right purpose to capture the benefits. Good soil management practices may be open to interpretation based on your personal goals for your garden space and remember that what makes sense in your landscape doesn’t always have to match what others are doing. If you are seeing positive results, then keep trying new techniques.

I hope that this Spring finds you dreaming and excited about the upcoming growing season and making a positive impact in adding diversity to your landscape. 

Resources for more information

Soil management in home gardens and landscapes | Penn State University

No-till gardening keeps soil — and plants — healthy | Oregon State University

Low and no-till gardening | University of New Hampshire

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.

Buckwheat: Pollinator Friend and More

Maryland GrowsLeave a comment
buckwheat flowers with a pollinators
Buckwheat flowers.

Where I grew up, we did not have a county fair, but instead a “Buckwheat Festival” which celebrated buckwheat pancakes. I’ve often heard stories about “old timers” planting buckwheat because it could thrive in poor soils. Buckwheat is not as well known or common as it was several years ago; however, it does have the potential to be a great addition to your landscape and would be a wonderful summer cover crop, which is just one way to help improve soils for a more climate- resilient garden.

Positives about buckwheat include that it matures quickly, is easily seeded by broadcasting, is relatively inexpensive to purchase by seed, is not “fussy” about where it grows, and germinates quickly. It does not mind low-pH soils and can even out-compete weeds! It has shallow roots and is easily terminated — so planting a new crop after it is no problem — or, if it is still growing in the fall of the year, a frost will kill it. Lastly, it is a wonderful nectar and pollen source for a wide variety of insects. 

Continue reading →

Select Ground Covers for Your Landscape Carefully

Maryland GrowsLeave a comment

Plants that are used as ground cover can provide great services throughout the landscape as they can fill in areas that might otherwise be left bare or covered in mulch. Ground covers can be used to help reduce maintenance chores by preserving moisture and preventing weeds. 

If you are looking for a ground cover plant, consider adding a native ground cover. Non-native ground covers and vines can be the plants of nightmares, as the characteristics that we like about them (aggressive, can take over weeds, need little care once established, etc.) are often the characteristics that make them terrible offenders when they escape into natural areas. A great field guide on this exact topic is Plant Invaders of Mid-Atlantic Natural Areas. 

Since it’s prime planting season in Maryland, here I highlight three herbaceous plants that are often used as ground covers that can quickly take over. For a more detailed list of some of the other ground covers that are concerning, check out this webpage, Invasive Vines and Groundcovers.

a covering of English ivy under a tree
near a forest edge English ivy is all over the ground and climbing up trees
English ivy (Hedera helix). Photo: M. Talabac, University of Maryland Extension

English ivy (Hedera helix) is sometimes just called “ivy” or “European ivy”, which reiterates the point that it is not a plant that is native to the United States. This evergreen, vining plant is one that you should be aware of as it can take over areas through the spread of seeds and through underground stems. It thrives in shade, is drought tolerant, and once established, it creates a thick, dense mat of foliage that can outcompete many perennials. It’s even been reported that it can damage homes/walls where it grows up and even penetrates the bark on living trees and strangles them. A study done in February of 2021 found that there are at least 5,000 trees in Takoma park could be lost because of English ivy. English ivy also serves as a reservoir for bacterial leaf scorch, a disease in maples, oaks, and elms.

For more information on English ivy, visit these webpages from the University of Maryland Extension: English Ivy and Invasives in Your Woodland.

Periwinkle (Vinca minor) close-up of purple flowers (left), and spreading along a staircase in Great Falls Park (right). Photos: M. Talabac

Periwinkle is a common plant that many people will recognize by its attractive shiny green leaves and purple-white flowers. There are actually two types, Vinca minor and Vinca major, unfortunately, both are considered invasive species and spread quickly vegetatively by root pieces (digging) and rooting at tips and nodes that contact the ground.

The third plant is bishop’s weed or goutweed (Aegopodium podagraria). Once established, this plant easily gets out of hand and is very difficult to remove. It is on the Maryland Department of Agriculture’s list of plants considered for regulation. Joyce Browning with the University of Maryland Extension in Harford County recently posted a video about bishop’s weed.

It can be overwhelming when considering adding plants in troubled areas. A great resource for ideas is the University of Maryland Extension webpage about Lawn Alternatives. 

Remember that you can help mitigate the negative effects of invasive plants on local ecosystems by not adding them to your landscape. However, if you already have some of these plants, you can also manage them correctly by keeping them contained in certain areas and eliminating their spread into natural areas. Never place yard trimmings into natural areas, and remove the seeds before they can be spread by wind, rain, and/or animals. As you are adding plants to your landscape, please check out these great resources for non-invasive plant suggestions: 

Landscaping with Native Plants- Maryland Native Plant Society 

Keystone Plants by Ecoregion- National Wildlife Federation

Resources on invasive plant identification: 

Plant Invaders of the Mid-Atlantic Natural Areas (PDF)

Do Not Sell! Ornamental Invasive Plants to Avoid with Climate Change (PDF)

Everyone can help in the fight against invasive plants! Check the University of Maryland Extension website for an Introduction to Invasive Plants in Maryland and more information on how to reduce them. The absolute best way is to just never plant or introduce them into your landscape. 

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.

Invasive Shrubs With Red Berries to Avoid

Maryland GrowsLeave a comment

Blooming flowers, emerging leaves, sprouting seedlings, and peeping frogs are just a few of the signs that encompass the magic of the spring season for me. As nature goes through the motions and awakens, I hope you have found some time to get outside and enjoy the wonderful gift of the changing seasons. Unfortunately, I’m always disheartened to see the number of invasive shrubs that are dotting the landscape this time of year. Spring is an easy time to see firsthand how invasive plants often break dormancy before native plants, which basically means that they leaf out earlier and have an automatic leg up as they are growing a few weeks before other plants. For more information, read Invasive Shrubs in Northeast Forests Grow Leaves Earlier and Keep Them Longer from Penn State. 

an invasion of bush honeysuckle plants covering a forest floor
Bush honeysuckle shrubs taking over a forest understory. Photo: Troy Evans, Great Smoky Mountains National Park, Bugwood.org

Q. What shrub has yellow-white (sometimes pink), trumpet-shaped flowers in mid-spring that smell sweet? 

A: Exotic bush honeysuckle is a large category of several different fast-growing species (Lonicera maackii, L. morrowii, L. tatarica, L. xbella, L. fragrantissima) that are perennial, deciduous shrubs that can grow up to 20 feet in height. These species share many of the same characteristics — yellow to white, sometimes even pink-colored flowers, sweet-smelling flowers, and red to yellow berries in early summer. Leaves are opposite on the stem. Wildlife such as deer and birds are known to spread these invasive shrubs by eating the berries. If you look underneath utility lines or at the forest edge, you will often see these invasive shrubs.

As of February 2018, the Maryland Department of Agriculture classified Amur honeysuckle (Lonicera maackii) as a Tier 1 invasive plant in Maryland. A person may not propagate, import, transfer, sell, purchase, transport, or introduce any living part of a Tier 1 invasive plant in the state. For more information visit the University of Maryland Extension page about Exotic Bush Honeysuckles. For control information, visit Invasives In Your Woodland: Bush Honeysuckles.

multiple white and yellow flowers of bush honeysuck
Bush honeysuckle flowers. Photo: Ryan Armbrust, Kansas Forest Service, Bugwood.org
multiple red berries on a bush honeysuckle shrub
Red fruits of bush honeysuckle. Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Over the last 5 years, I’ve seen a huge increase in the number of invasive shrubs in my own woodlot, which is secluded from homes due to the mountainous terrain. Nonetheless, Japanese Barberry (Berberis thunbergii) has begun taking over the understory and edges of hayfields. I believe that it was spread by wildlife. Did you know this shrub gets small yellow flowers in early spring and then red berries?

yellow flowers of Japanese barberry
Japanese barberry flowers are yellow. Photo: Miri Talabac, University of Maryland Extension
red berries of japanese barberry
Japanese barberry fruits. Photo: Richard Gardner, Bugwood.org

Q. I see Japanese barberry planted in many landscapes. Is it really an invasive plant?  

A: This invasive shrub has been used in landscapes in North America since the late 1800s. It is very popular because it provides resistance to deer browse and can grow in a wide variety of light and soil conditions, making it a plant that can be used dependably in home landscapes. However, these characteristics contribute to its aggressive nature when spreading into natural areas. It forms dense foliage thickets that create an ideal humid environment for black-legged ticks (deer ticks) which can carry the pathogen that causes Lyme disease.

The Maryland Department of Agriculture (MDA) has named this a Tier 2 invasive plant. This classification means retail stores that offer this plant for sale must display a required sign indicating that it is an invasive plant. Landscapers may not supply Japanese barberry unless they provide the customer with a list of Tier 2 invasive plants. In our neighboring state of Pennsylvania, Japanese barberry is on the noxious weed list and will be banned for sale beginning this fall.

Visit the University of Maryland Extension website for more information about Japanese barberry and how to control it.

Japanese barberry infestation in a forest. Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Q.  I want to add a shrub to my landscape that provides berries for the wildlife and fall foliage color. Is burning bush (Euonymus alatus) a good choice?

A: Unfortunately, winged burning bush (Euonymus alatus) is not the best choice when adding a new shrub to your landscape, as the Maryland Department of Agriculture (MDA) has named this a Tier 2 invasive plant. This classification means retail stores that offer this plant for sale must display a required sign indicating that it is an invasive plant. Landscapers may not supply winged burning bushes unless they provide the customer with a list of Tier 2 invasive plants. It is also important to note that burning bush is now a banned noxious weed in our neighboring state of Pennsylvania.

For more information, check out this previous blog post, Q & A: Is Burning Bush an Invasive Plant? For control suggestions, refer to Invasives in Your Woodland – Winged Euonymus.

leaves of burning bush
Burning bush branch. Photo: Richard Gardner, Bugwood.org
red berries of burning bush
Burning bush fruits. Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Q. Does Heavenly bamboo support wildlife with its evergreen leaves and red berries? 

Heavenly bamboo, sacred bamboo, or Nandina (Nandina domestica) has berries that are actually toxic to cats and also cedar waxwing birds. This plant was introduced from Asia in the early 1800s but it outcompetes many native plants with its aggressive nature.

MDA has named Nadina a Tier 2 invasive plant. This classification means retail stores that offer this plant for sale must display a required sign indicating that it is an invasive plant. The Nandina cultivar ‘Firepower’ is the only exception.

For more specifics about this plant, read Not so Heavenly from the Maryland Invasive Species Council. The Master Gardeners of Northern Virginia have a good list of native alternatives to plant instead.

Invasive heavenly bamboo (Nandina domestica). Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

All of these invasive shrubs produce berries which is one of the ways they spread so widely and easily. Please research plants before adding them to your landscape. Below are links for information on finding non-invasive plants: 

Native Shrubs – University of Maryland Extension

Landscaping with Native Plants- Maryland Native Plant Society 

Keystone Plants by Ecoregion- National Wildlife Federation

Resources on invasive plant identification: 

Plant Invaders of the Mid-Atlantic Natural Areas (PDF)

Regional Invasive Species & Climate Change Management Challenge: Do Not Sell! Ornamental invasive plants to avoid with climate change

Check the University of Maryland Extension website for an Introduction to Invasive Plants in Maryland for more information on how to reduce them.

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.

Invasive Trees in Maryland: Princess Tree, Callery Pear & Tree-of-Heaven

Maryland Grows4 Comments

Last month, my blog post was an introduction to invasive plants and today I want to share information on three invasive, deciduous trees found in Maryland. 

Springtime provides a breathtaking display of contrasting flowers in a wide array of colors, shapes, and sizes, which are found in herbaceous plants, as well as woody shrubs and trees. Unfortunately, some of these spring flowering trees are invasive and you need to be aware of their negative effects on ecosystems such as competition for resources including sunlight, soil nutrients, and space.

Q: What medium-sized invasive tree has white blooms in the early spring in Maryland?

invasive callery pear trees crowded along a road
Callery pear (Pyrus calleryana) in flower. Photo: Britt Slattery, US Fish and Wildlife Service, Bugwood.org

Callery Pear (Pyrus calleryana), sometimes referred to as ‘Bradford’ Pear, has several cultivars including ‘Chanticleer,’ ‘ Cleveland Select’, and ‘Autumn Blaze’, all of which will be in bloom around this time of year. The Callery pear was imported from Asia to Maryland with the hope of being able to help edible Bartlett pears, which were being threatened by a disease called fire blight. The plan was to cross these pears to gain disease resistance in the pear industry. Unfortunately, this experiment was unsuccessful in preventing fire blight, but these crosses seemed to have potential for the ornamental industry and were planted widely. Bloom time often coincides with our native serviceberry, which produces white flowers too.

The ‘Bradford’ cultivar was thought to be sterile; however, when new cultivars of Callery pear were developed, it was able to cross-pollinate with those and produce viable seeds. Birds and other wildlife eat the fruits, which results in spreading them to different areas. The seeds sprout and grow into dense thorny thickets, which are very difficult to control and result in crowding out native vegetation. Callery pear provides a stunning show of beautiful white blossoms; unfortunately, these trees are highly invasive, which has led a few states to ban all cultivars of Callery pear (Pennsylvania, Ohio, and South Carolina). This tree has an attractive V-shaped crotch that unfortunately will often split from high wind and snow weight damage. 

For more information, history, and control options, please visit the University of Maryland Extension webpages: Invasives in Your Woodland and Bradford Pear.

Q:  What invasive tree has purple blooms in early spring?

lavender flowers of princess tree

Princess Tree (Paulownia tomentosa). Photo: Leslie J. Mehrhoff, University of Connecticut, Bugwood.org

Paulownia (Paulownia tomentosa), also called princess tree or empress tree, has purple, pleasant-scented blooms that appear before the foliage in early spring. I saw this tree for the first time when I traveled to Howard County for training in 2012, as this is not a tree we have in Garrett County. Its striking, large, heart-shaped leaves automatically caught my attention and reminded me of the Northern catalpa tree, a great native tree that should not be mistaken for Paulownia. According to Plant Invaders of the Mid-Atlantic Areas, one empress tree is capable of producing 20 million seeds that mature to flowering in only 10 years! These trees prefer full sun but can grow on disturbed soils, creek banks, and even forested areas which gives them a big advantage over native species that often require more special environments to grow and thrive. Paulownia’s ability to sprout from adventitious buds on stems and roots allows it to survive fire, cutting, and bulldozing. It is, therefore, a very difficult and costly invasive plant to control, according to the Maryland Invasive Species Council Plant Invader of the Month listing. 

A great alternative to Paulownia is the native Eastern redbud, which produces early, purple/reddish-purple blooms. 

For additional information, history, and control options for Paulownia, visit the University of Maryland Extension web pages Invasives in your Woodland and Princess Tree. 

Q: What invasive tree looks similar to black walnut?

tree of heaven foliage looks very similar to that of black walnut and sumac
Tree-of-Heaven (Ailanthus altissima). Photo: Chuck Bargeron, University of Georgia, Bugwood.org

Tree-of-Heaven (Ailanthus altissima) was introduced in the late 1700’s and thrives in many soil conditions. It has an amazing ability to grow very quickly and can disturb building foundations and even pavement! It was widely planted as a street tree and thus is found far and wide in the Eastern United States. This tree is called by other names including China-sumac, stinking sumac, or varnish tree due to its strong unpleasant odor. Tree-of-Heaven is sometimes mistaken for sumac, hickory, or black walnut because of similarities in leaf shape; however, look for the glands on the bottom of each leaflet to confirm its identity. 

Just in case you needed one more reason to remove Tree-of-Heaven, it is a preferred food source for the new, exotic, invasive insect pest, spotted lanternfly.  

For more specific information, history, and control options, visit these web pages:

Keep an eye out this spring for non-native, invasive trees as there are many others that I did not address in this article. Take any opportunity to help educate friends or family about the negative impact of invasive plants on biodiversity.   

Resources for invasive plant identification: 

Resources for non-invasive plant suggestions: 

Check out the University of Maryland Extension website on Introduction to Invasive Plants for more information on how to reduce invasive plants.

Remember, the absolute best way to avoid invasive plants is to never plant or introduce them into your landscape! 

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland. Read more posts by Ashley.