Maryland Grows

Holiday Gifts for Gardeners

gift packages

Gifts for Gardeners. Photo: Pixabay

Sweaters, socks, and chocolate-coated espresso beans are among the gifts that, for me anyway, fall into the essential and expected holiday gift category. But if you want to “wow” the gardeners in your life this year, consider these ideas from the past and future wish lists of your friends at the Home and Garden Information Center.

The best gift I ever received WAS a garden. My husband rented a rototiller and got the whole area ready to plant. Another option would be to give someone a container or salad box already planted with lettuce seedlings or herbs.

Marian and Debbie like the Garden Rocker Comfort Seat. A simple, low, plastic stool gets you close to your plants, soil, and weeds (claims to reduce knee & back strain). It’s available at some local retailers and online.

Sara says that those little tree finders (tree ID) booklets make nice stocking stuffers.

Master Gardener Handbook

Photo: UME Master Gardener Program

Chris loved Birds and Blooms magazine when the kids were small… gorgeous photography. And don’t forget about the Maryland Master Gardener Handbook. It’s a fabulous gardening resource.

Lew has the giving spirit and likes the idea of a subscription to one of the local or national gardening magazines, like the Washington Gardener, or a gift certificate from a local nursery. You could even give someone a gift card and let them shop online for the tool or accessory that they like.

salad box

A Salad Box™ is another name for a table-top garden. Photo: HGIC

A handyman or woman could build a salad table or salad box for a friend who has trouble getting up and down in the garden or for anyone with limited space to plant an in-ground garden. A “coupon book” offering your garden services would be a nice stocking stuffer. Decorative stepping stones would be a lovely addition to any garden!

How about a couple of passes into one of the popular private or public gardens, or simply offering to take a friend on a springtime walking tour of the National Arboretum, Brookside Gardens, or Longwood Gardens?

For the avid gardener, how about a gift basket containing garden accessories: plant ties, netting, a floating row cover, a pair of inexpensive garden gloves, a bottle of wine, and some herb markers? With a simple Google search, you can find nifty gardening tools that everyone at HGIC loves, like a stainless steel soil knife in a handy sheath. Or pair the soil knife with a pruner in a combo sheath to hook onto a belt.

National Arboretum

National Arboretum. Photo: Pixabay

Lisa thought it would be great to receive a gift of membership to a horticultural group or the Maryland Native Plant Society, or a collection of seeds from Monticello or Mt. Vernon. The National Wildlife Federation has tree sponsorships and ornaments that when purchased, plants a tree. Or how about a living succulent wreath or a personal gift certificate of your time to help weed, plant a new bed, etc.

Give where it is needed the most. Make a donation in a friend’s name to a charitable organization like Heifer International. Your gift in support of sustainable farming can change lives.

Ginny likes practical garden gifts, like Liquid Fence to repel deer, or deer netting or a privacy fence to keep them out of the garden!

Make 2019 a happy gardening year with gifts from the heart and for the garden.

By Ria Malloy, Program Coordinator, Home & Garden Information Center

Monthly Tips for December



  • To keep holiday plants looking good longer, keep them away from dry, drafty locations. Do not place near heat vents, doorways or drafty windows. Increase humidity around plants by placing them on a tray lined with pebbles, shallowly filled with water. Make sure the water does not enter the drainage holes. For information on caring for Poinsettias refer to (PDF) HG 30 Poinsettias.
  • Winter is a challenging time for most houseplants because of the lower natural light and susceptibility to being over watered.  Growing media should be allowed to dry out between watering.
  • Unless your indoor plants are growing under optimum, high light conditions, do not fertilize them during the winter months.


Mantid Egg Case

Mantid Egg Case

  • You may notice insects and spiders emerging from around your Christmas tree. They came in unnoticed on your tree. Simply escort them outside or vacuum them up.
  • The brown marmorated stink bug is settling down in nooks and crevices in houses and buildings for the winter. You may see several moving about in your home especially on warmer sunny winter days. Do not use insecticide sprays in your house to kill them. Capture and dispose of them using your shop vac. The stink bug is likely here to stay for a while, but like all insects may display fluctuating population cycles.
  • Miscellaneous beetles, like long-horned beetles and bark beetles may emerge from firewood stored inside the home. These are nuisance pests; they are not a threat to the wood in your home. You can also prevent pests from coming into the house by storing firewood outside the house.


Trees and Shrubs

  • In a “normal” year in our region we do not get much ice or snow in December, but if we do, try to prevent it from building up on gutters and eaves above shrubs. Heavy snow and ice loads can break branches. Using an upward motion, gently sweep snow loads off of shrubs to prevent breakage. Sweep snow and ice off shrubs with an upward motion.
  • Trees and shrubs can be pruned now. Remove dead or diseased branches and make any necessary cosmetic cuts. Remove broken branches and make pruning cuts back to healthy wood. Extensive pruning of spring flowering plants such as azaleas, rhododendrons, and dogwoods will reduce the number of blooms in the spring. If you do not desire to reduce flowering, wait until after they bloom next spring to prune them. (Watch our pruning videos)
  • Evergreens such as hollies, boxwoods, and pines can also be moderately pruned this month. The trimmings can be used for holiday decorating.

More tips from the Home & Garden Information Center

The Home & Garden Information Center’s horticulturists are available year-round to answer your plant and pest questions. In addition to gardening questions, we cover houseplants, indoor pests, and more. Send your questions and photos to Ask an Expert!

Urban Landowners in Maryland Have a Duty to Inspect Property and Handle Diseased or Damaged Trees to Prevent Damage to Neighbors

tree limb with symptom of wood decay

Tree limb (on the left) with wood decay symptom. Photo: University of Maryland Extension Home and Garden Information Center (HGIC)

This is not legal advice.

A frequently asked question is what a homeowner can do when a neighbor’s tree has become diseased and poses a danger. The neighbor may be trying to treat the tree to save the tree or might not be able to afford to have the tree taken out correctly by a trained professional. In these cases, courts have found that a residential property owner has a duty to eliminate the danger posed by a diseased tree and prevent the tree from damaging a neighbor’s property. The exception to this would be when a healthy tree causes damage due to an act of God, such as a storm.

Maryland courts have not explicitly dealt with a diseased tree falling on a neighbor’s property. The Court of Special Appeals has dealt with the issue of a motorist injured by a tree limb falling through his windshield. In this case, the motorist was driving through a recently finished subdivision in a natural woodland area of Montgomery County, and the tree limb fell due to the natural decay process. The court highlights that a landowner would need to be aware that the tree was in a deteriorated condition. Urban landowners would have a duty to inspect trees on their properties to determine if trees are dangerous. This duty to investigate would not extend to rural property owners and owners of suburban forests due to the size and number of trees on these tracts of land.

During the inspection, the urban landowner would have to deal with any discovered diseased trees. An urban landowner with a diseased tree would be under a duty to eliminate the danger to prevent the diseased tree from falling or damaging a neighbor’s property. If the urban landowner does not do anything and the tree damages a neighbor’s property, then the urban landowner would face potential legal liability for the damage caused by the falling tree.

Looking at an example, an urban landowner who has a tree with Emerald Ash Borer damage, the landowner would need to either treat the tree and deal with dead limbs that could damage a neighbor’s property or have the tree removed. If the urban landowner fails to do this or the tree continues to decline after the treatments and the landowner fails to do anything, and the tree damages a neighbor’s property, then the urban landowner would be liable to the neighbor for the damages caused by the tree.

tree with emerald ash borer damage

Emerald ash borer damage. Photo: UME HGIC

One case where a property owner might not see liability from damages caused to a neighbor’s property from a tree would be with an act of God. Acts of God are typically events such as storms, earthquakes, or another events outside of human control. If the tree owner can show the tree fell due to the act of God and not due to disease, then the tree owner will typically not be liable for the damage.

Urban landowners with trees need to take into account that there is a duty to inspect trees in Maryland. Excluded from this duty would be rural landowners and suburban forest landowners. If a diseased tree is found on the property, then the urban landowner would need to either treat the tree or have the tree removed to prevent the tree from damaging neighboring landowners. University of Maryland Extension’s Home & Garden Information Center provides resources, for example, on handling issues such as Emerald Ash Borer and other tree pests and diseases.


Hensley v. Montgomery County, 25 Md.App. 361 (1975).

The University of Maryland Extension. Home & Garden Information Center: Emerald Ash Borer (EAB), available at (last visited, Nov. 15, 2018).


How Do You Decide When to Remove a Tree? University of Maryland Extension Home & Garden Information Center

By Paul Goeringer, Extension Legal Specialist, Department of Agricultural and Resource Economics, College of Agriculture and Natural Resources, University of Maryland

Pine Trees: Browning Foliage and Pine Cones – Featured Video

David Clement, Extension Specialist and Plant Pathologist, explains two common concerns homeowners have with their pine trees in the fall season: browning foliage and “what are these growths?” (hint: they’re just pine cones).

Gleaning Results in Bountiful Harvest, Less Food Waste

harvesting sweet potato greens

Photo: Cheryl Kollin, Community Food Rescue

“Now when you reap the harvest of your land, you shall not reap to the very corners of your field, nor shall you gather the gleanings of your harvest.”

This passage from Leviticus 19:9 refers to the ancient practice of gleaning food after the harvest leaving food in the field for those in need. This ancient practice in spirit and deed are just as relevant today. In keeping with Community Food Rescue’s goal to feed more and waste less, we’ve partnered with University of Maryland Extension (UME),  UME Montgomery County Master Gardeners, and the Montgomery County Food Council to glean food that is not economically viable for commercial harvest.

Master Gardener gleaners

UME Master Gardeners, strawberry harvest. Photo: Cheryl Kollin, Community Food Rescue

This year, thanks to generous gleaning opportunities from Red Wiggler Community Farm, Butler’s Orchard, and Farm at Home, we’ve gleaned 248 lbs. of strawberries, 338 lbs. of blueberries, 32 lbs. of sweet potato vines, and 600 pounds of apples. The gleaned fresh produce was donated to Washington Grove and Sally K. Ride Elementary Schools, The Judy Center at Summit Hall Elementary School, and CFR network members.

strawberries in containers

Strawberries ready for distribution at Sally K. Ride Elementary School. Photo: Pam Hosimer

Sweet Potatoes: More than Just a Tuber

Blog excerpt courtesy of Red Wiggler Community Farm:

On August 20th, 2018 we invited a group of volunteers to our site at Ovid Hazen Wells Park to glean sweet potato greens. This project was a partnership between Community Food Rescue, University of Maryland Extension, School of Supplementary Nutrition Education, the UME Montgomery County Master Gardeners, and The Montgomery County Food Council. We welcomed the opportunity to have this group work with growers to harvest a portion of this plant that has historically been underutilized.

stripping greens of sweet potatoes

Photo: Cheryl Kollin, Community Food Rescue

Sweet potato greens have a surprising history in the Mid-Atlantic region of North America. Many Americans enjoy sweet potatoes during the holidays, as harvesting is at its peak from October to early December. While most associate eating sweet potatoes with the tuberous root portion of the plant, West African & Asian communities have incorporated the greens into their culinary practices for ages.

Like beet greens, the greens of sweet potatoes can be sautéed and prepared as a main or side dish. The leafy treats are packed with nutrients; in fact, they tend to hold three-times more vitamin B6, five-times more vitamin C, and close to ten-times more riboflavin than the root of the sweet potato.

Despite the apparent value of this part of the sweet potato, farmers often waste this part of the plant because of a lack of demand from commercial entities. Red Wiggler was thrilled to welcome our partner organizations to assist in delivering this super green to Shepherd’s Table, a nonprofit that has provided food to low-income families in Montgomery County for over 30 years.

Sweet potato greens being delivered

Community Food Rescue’s (CFR’s) Susan Wexler delivers sweet potato vines to Chef Christina Moore at Shepherd’s Table. Photo: CFR

Gleaning, Cooking, Eating, Sustaining

Shepherd’s Table Chef Christina Moore cooked the greens a few days after harvest as part of their chicken dinner for 120 people. “The guests loved them, and I got to try something new! Feel free to send any more our way!!”

Gleaning provides the opportunity to learn about modern-day issues in our community. Red Wiggler Community Farm Executive Director, Woody Woodroof joined the October 20th staff and gleaners for lunch and discussed food waste and food insecurity in Montgomery County. Woody summed up the big picture perspective of gleaning explaining, “partnerships like these allow Red Wiggler to give back while pursuing its long-term sustainability goals.”

Republished with permission from Community Food Rescue, with thanks to Program Director Cheryl Kollin and Outreach Coordinator Susan Wexler.

2018 Vegetable Garden Re-cap

This is a good time to think about what worked and what didn’t work so well in our 2018 garden spaces. What was unexpected, which weeds and diseases were challenging, how can we prevent problems and have greater success next year? In that spirit, and before they become dim memories, I’ll share a few observations from the past growing season.


No two years are alike when it comes to weather and food gardening, but wow, 2018 was unusual! We had a slow spring warm-up and record rainfall in Maryland for the May-July period with multiple 2+ inch rain events (NOAA, 2018; Baltimore Sun, 2018). Unfortunately, extreme weather events and above-average rainfall is consistent with the climate change models for the mid-Atlantic region.

The combination of environmental factors- excess rain, wet soils, wildly fluctuating spring temperatures, and high heat and humidity through much of the summer- contributed to a lot of plant stress, leached nutrients, soil erosion, increased disease and weed pressure, and decreased yields.

Learn more about climate change and how gardeners can meet the challenge on HGIC’s climate change page. Also, at the bottom of the page you will see Climate Change in Your County. This little gem is from the Climate Smart Farming program at Cornell University and presents data graphs of temperature and precipitation changes since 1950 in all Northeast counties.

Edema (burst plant cells) of tomato seedlings


Photo: Submitted to University of Maryland Extension by a client

Too much water inside the home! Jerry Brust, Ph.D., Vegetable IPM Specialist, identified excessive watering as the cause of these tomato transplant symptoms. “Loving them to death” is a common gardening disorder. Let the top of the growing medium dry a bit before watering.

Leaf spot diseases on Roselle hibiscus

Roselle sabdariffa is a fabulous plant grown by many gardeners of Indian and West African descent. It has a lemon-sour taste similar to French sorrel. There are several leafy types that are harvested throughout the growing season.

Leaf spot diseases on Roselle hibiscus

Photo: Jon Traunfeld

I’ve observed these plants in community gardens in Central Maryland for many years and saw no disease problems. This year, leaf spot symptoms appeared late summer in Howard Co. I sent a sample to the UM Plant Diagnostic Lab. Three different fungal pathogens were found on the sample and the symptoms are most consistent with Cercospora leaf spot, a disease known to infect Roselle. The lab provided excellent recommendations for preventing or minimizing the problem next year: keeping the foliage dry (no overhead watering), remove infected debris at the end of the season to reduce inoculum, and plant it in a different part of the garden next year.

Rainstorms washed away precious soil

Torrential July downpours

Photo: Jon Traunfeld

Torrential July downpours washed unprotected soil onto streets and down storm drains across the region. Clay and organic matter particles were washed away with the rain leaving silt, sand, and stones in the road. Negative environmental effects at one location affect the ecosystem downhill and downstream.

All boys (for a while) club

This young zucchini plant produced 12 male flowers (on straight stalks known as pedicels) before the first female flower (undeveloped fruit, the ovary, forms below the un-opened flower). Be patient- this is normal for most species and varieties in the Cucurbitaceae family.

young zucchini plant

Photo: Jon Traunfeld

Must prevent tomato diseases, must prevent tomato diseases, must prevent…

of tomato- early blight

Photo: Jon Traunfeld

The principal fungal leaf spot diseases of tomato, early blight (above) and Septoria leaf spot, can be effectively managed so that decent crops are harvested each year. Reduce infection and spread by planting clean seed and transplants, 2 ft. minimum spacing, removing lower leaf branches, watering at plant base, removing all plant debris at season’s end.

Go deep for dependability

I love these examples of deep and productive raised bed gardens at the Friends House community garden in Sandy Spring.

Life is impermanent (including blackberry)


Photo: Jon Traunfeld

The excavated crown of an 8-year old blackberry plant that was infested with rednecked cane borers. The plants were also infected with spur blight, a fungal disease and possibly other pathogens. HGIC strongly recommends bramble fruits because they are dependable and can be grown organically. But they are susceptible to many insect pests and diseases and may become so weakened that they need to be removed.

Enjoy your Thanksgiving and start dreaming about next year’s garden!


By Jon Traunfeld, Extension Specialist

The Nativar Dilemma: The Case of My Purple Ninebark & The Leaf Beetle

Physocarpus opulifolius 'Diabolo'

Ninebark ‘Diabolo’. Photo by F.D. Richards. Source: Flickr Creative Commons

I thought I was doing the right thing. When I moved into my house 11 years ago, I found a purple barberry shrub (Berberis thunbergii) planted in the back yard by the previous owner. I thought right away, it had to go. I knew Japanese barberries, so commonly planted in landscapes, were escaping into natural woodland areas and creating dense thickets to the exclusion of native plants. These thickets have been shown to make suitable habitat for Blacklegged Ticks. I wanted no part in contributing to that situation, so I donned my work gloves and removed that prickly beast of a shrub.

In the barberry’s place, I planted a “native” purple-leaf ninebark, Physocarpus opulifolius ‘Diabolo’. It had deep burgundy foliage that made a nice replacement for the burgundy-toned barberry. And, I was selecting a Maryland native plant. I thought it was a perfect choice.

I sang praises about this ninebark for years when people asked me for native plant recommendations. It has great spring blooms, beautiful foliage color, and I never had to prune it. And native plants support native insects so I was doing a good thing to help wildlife. I was doing the right thing!

Or so I thought.

It was just this year that I learned from my colleague, native plants specialist Dr. Sara Tangren, that this particular cultivar of the native ninebark was actually detrimental to a specific native insect, the Ninebark Leaf Beetle. My heart just sunk when I heard this. I am first and foremost a plant enthusiast, but I also appreciate insects—the essential roles they play in our world as well as their often stunning beauty. And when I looked up the Ninebark Leaf Beetle, I discovered that it is indeed a beauty. And then my heart sunk even further. My purple ‘Diabolo’ ninebark, it turned out, was no good for this native beetle. The alteration in the leaf color – changing the green of the native species to the burgundy of the cultivar – makes it distasteful to the beetle.

Ninebark Beetle

Ninebark beetle. Photo: Pennsylvania Department of Conservation and Natural Resources – Forestry,

The effects of altered leaf color on plant-feeding insects was noted in a new study published in HortTechnology magazine last month. The authors (Baisden et al.) conducted experiments on several native woody plant cultivars compared to the straight natural species. They looked at whether six altered traits in the cultivated varieties – leaf color, variegation, fall color, growth habit, disease resistance, and fruit size – had any effect on insect feeding, development, and abundance.

In all three experiments they conducted, the researchers found that the cultivars with leaves that were altered from green to red, blue, or purple deterred insect feeding. Results were not consistent for the other cultivar traits they tested.

ninebark leaf variations

Ninebark cultivars, ‘Lady in Red’, ‘Dart’s Gold’, ‘Diabolo’. Photo: Leonora (Ellie) Enking, Flickr Creative Commons

There are a couple hypotheses as to how leaf color affects insect feeding. Most plant pigments are compounds that do not contribute to the growth of a plant. They may instead provide a defense mechanism. Anthocyanin pigments make a red coloration that may warn insects that the plant has defensive, distasteful chemicals – and they stay away.

The question of whether cultivars of native plants – nativars – have positive or negative effects on native wildlife is an active and ongoing area of research. Results in past studies have been mixed. (For more on this topic, see Mt. Cuba Center research).

Physocarpus opulifolius

The native species of ninebark, Physocarpus opulifolius, has green foliage. Photo: John Ruter, University of Georgia,

I know how appealing it is to choose plants with special characteristics – the colored foliage, bigger flowers, the more compact form or general appearance that suits my personal taste. But my choices may not, in some cases, be to the taste of other things in our environment and the things that depend on them for food. It is a dilemma. I do like specific non-native plants (I’ll never give up my dahlias), but I also adore the lilting songs of chickadees in the springtime. Many birds like Carolina chickadees need caterpillars to feed their young and many caterpillars can only feed on wild, native plants. See New Smithsonian Study Links Declines in Suburban Backyard Birds to Presence of Nonnative Plants. I should note that a different study (Craves) found that native birds, including chickadees, were able to find insect food on non-native, invasive Amur honeysuckles. (Which makes the issue even more confusing, right?)

“When we try to pick out anything by itself, we find it hitched to everything else in the Universe.” – John Muir

For an ecologically minded gardener, it feels complicated to sort this all out and do the right thing. I felt disappointed that my ‘Diabolo’ ninebark was a missed opportunity to support a particular native insect, but, as Dr. Trangren explained to me, it becomes more of a problem when cultivated nativars cross-pollinate with the wild species and change the genetics of the native populations, making them less capable of supporting insects on a broader scale. For this reason, she recommends choosing cultivars that are sterile.

It was a lesson learned and one that makes me more thoughtful about my plant choices and their broader impacts.

By Christa K. Carignan, Maryland Certified Professional Horticulturist; Coordinator, University of Maryland Extension Home & Garden Information Center.


Craves, Julie A. 2017. Native birds exploit leaf-mining moth larvae using a new North American host, non-native Lonicera maackii. Écoscience, 24:3-4, 81-90.

Baisden, Emily C., Douglas W. Tallamy, Desirée L. Narango, and Eileen Boyle. 2018. Do cultivars of native plants support insect herbivores? HortTechnology 28(5) 596-606.

Narango, Desirée L., Douglas W. Tallamy, and Peter P. Marra. Desirée. 2018. Nonnative plants reduce population growth of an insectivorous bird. Proceedings of the National Academy of Sciences of the United States of America.

Learn more about native plants on the University of Maryland Extension Home & Garden Information Center website.