Readers’ 2020 Gardening Highlights Vol. 2

At the end of 2020, we asked readers to share any notable stories, projects, or accomplishments from their past year in gardening activities. We received some great submissions. We will feature a portion of the submissions in this post and more in the future.

View more 2020 Highlights

Pollinators love Mexican sunflower

Anne Henochowicz in Montgomery County wanted to share her success with this pollinator attracting plant.

Pumped about pumpkins

Kelly Domesle and daughter Helena had great success with pumpkins down in Washington D.C.

“During the shutdown this Spring, we spent an afternoon exploring the physics of “Pumpkin smashing” from our deck. My daughter, Helena, salvaged a few pumpkin seeds and planted them in our front yard. I was skeptical, but she tended to the plants all summer and had an amazing harvest this Fall! People stopped and talked to us about our pumpkin patch all year and we loved watching the bees buzzing in and out of the flowers. We gave the pumpkins away to neighbors and cooked some, too.”

  • Pumpkin harvest
  • Big pumpkin patch
  • Pumpkin vine

Brittany’s bountiful Baltimore garden

Brittany Croteau, a Master Gardener in Baltimore City shared her amazing turf reduction/garden expansion, native flowers, and fruit and vegetable haul this year:

“Over 2020 I anticipated having a really sad garden year… I was newly pregnant, and had just accepted a promotion which had me traveling to Cecil County daily, which left me with little time to think about my garden. Then COVID hit and I found myself at home 24/7, with a LOT of free time on my hands. My husband and I decided to rededicate that time to our garden, removing more turf, planting more natives, and meeting (socially distanced) with neighbors to swap produce and flowers. This year was the most fruitful garden we had, both with native plants, native birds, and veggie production. I was so grateful to spend time outside and create a space I was happy to welcome my daughter into in August 2020. A year I thought my garden was going to be neglected ended up being our best garden year yet. “

The Itchy Truth About Poison Ivy

poison ivy vine climbing a tree
Poison ivy uses hairy aerial roots on its vines to cling to trees. Photo: Betty Marose

It starts with a twitch and an itch. Then it grows into full-blown scratchiness and dreadful knowing. You have poison ivy. Again.

I tip my hat to those immune to the maddening rash that contact with this plant brings. You are indeed the Fortunate Ones. The rest of us will try to quiet our whimpering.  

It pays to know the enemy. Poison ivy is a perennial plant that can climb trees as a vine, form a shrub, or snake over the ground. It spreads by seeds and rhizomes, sneaky underground stems that help it form colonies. 

A native plant whose berries feed over 50 species of birds, poison ivy has glossy leaves, attractive berries, and striking fall color. If it weren’t for the itch, we’d love it. 

The key to managing poison ivy is learning to recognize it. “Leaves of three, let it be,” is a wise adage. Most poison ivy has three pointed leaflets that form one compound leaf. 

young poison ivy plants have three leaflets
Poison ivy has compound leaves with three leaflets which inspire the phrase, “Leaves of three, let it be.” Photo: University of Maryland

Nearly all poison ivy leaves have wavy or toothed edges, but some are smooth. In spring, they are shiny and reddish, turning green as they mature. In the fall, leaves turn yellow, orange, or red.

Another giveaway is poison ivy’s hairy vines bristling with aerial roots that help it cling to trees.

Lookalikes abound. Virginia creeper has similar leaves with 5 leaflets to each compound leaf. Box elder seedlings have nearly identical 3-part leaflets. When in doubt, steer clear.

To help you tell the real deal from imitators, we’ve created a handy identification guide with photos here.

Every part of the poison ivy plant – leaves, stems and roots – carries an oil called urushiol that irritates skin. Even dead plants can cause a rash.  

Symptoms of exposure – itching, burning, swelling, rash and blisters – can show up a few hours to a few days after contact. You can also get it from tools, clothing, or pets.  

How do you prevent the torment that is a poison ivy rash? Learn to identify and manage the plant and treat yourself after possible exposure.  

Cover up well with long pants and shirt and gloves and dig out, bag, and trash small plants. Or spot-spray foliage of small plants with a non-selective herbicide with glyphosate, being careful to avoid desired plants.  

Penn State University advocates using the “glove of death.” Don nitrile or other chemical-resistant gloves, then cotton gloves, and wipe a glyphosate solution onto small plants.   

If poison ivy vines are growing up your trees, cut the vines to starve the top. Never burn poison ivy. That can send its irritating oils into the lungs and you to the hospital.

The best time to treat poison ivy is early to mid-summer when it’s actively growing, but now is not too late. After contact, wash clothing separately from other laundry and carefully clean tools.  

Now you have the tools to identify and manage poison ivy. Forewarned is forearmed. And much less itchy.

By Annette Cormany, Principal Agent Associate and Master Gardener Coordinator, Washington County, University of Maryland Extension. This article was previously published by Herald-Mail Media. Read more by Annette.

Why Do Pollinators Visit Flowers? Hint: It’s Not Just for Nectar and Pollen

Other than because I think they are pretty, I love looking at plants and their flowers. In fact, one of my pastimes has become figuring where and what is the reward that pollinators get out of their visits to their favorite flowers. You may be now thinking that my pastime is a bit nonsensical, since it is pretty clear that pollinators get pollen and nectar from flowers, so why bother checking? Well, actually, that is only partially true; did you know there’s a myriad of rewards that pollinators can get from their flower visits?

In today’s post I want to tell you a bit about some of those other rewards; the ones that fascinate me so much. Let’s talk about special floral pollination rewards and where you can see them in real life!

We like essential oils, some pollinators like floral oils!

The first time I heard about floral oils my mind was blown in such a way that I became obsessed with them, to the point that now a large part of my research program focuses on them. Floral oils are a reward that many types of plants offer to their favorite pollinators: oil-bees.

But don’t let me get ahead of myself! Floral oils are a special type of oil – different from essential oils – that are produced and presented to pollinators on different parts of the flowers of some plants. Independently of what exactly they look like, all these plants are visited and pollinated in a very specialized way by oil-bees. Unlike honeybees, these oil-bees are solitary and make their nests in the ground. These oils help these bees line their nests to waterproof (!!) and strengthen them. Along with that, they also mix the oils with pollen and feed that ‘pollen ball’ to their larvae.

Macropis oil bee
The whorled yellow loosestrife (left; photo: Eli Sagor) is one of Maryland’s native plants that offers floral oils to their Macropis oil-bees (right; photo: Don Harvey). Note the shiny load of oils and pollen on the hind legs of this Macropis!

Oil flowers are present all around the globe. In our region, they are represented by several species of the yellow loosetrife plant genus Lysimachia. With their floral oil rewards, these loosestrifes sustain the rare oil-bees of the genus Macropis. At the level of the country, most oil-flowers (and their specialized pollinators) are restricted to the Southern USA, where they are visited by the large bee genus Centris. Some of these plants are the wild crapemyrtle, the prairie bur, and the purple pleatleaf.

Hungry? Please, help yourself!

Along with nectar, pollen, and floral oils, food for pollinators can come in many different shapes and forms. In fact, some flowers even offer parts of their flowers to their pollinators. In cases like this, flowers develop special structures – usually around their petals – with the only function of becoming food for pollinators. Flowers providing this type of reward are usually pollinated by beetles, who can use their strong mandibles to chew on and eat the special structures.

calycanthus
Sweet shrubs display nutritious structures to their pollinators, small sap-feeding beetles of the family Nitidulidae. Photo: Wikipedia commons.

One of the coolest examples of the use of this type of reward is our very own sweet shrub, Calycanthus floridus. This spring flowering plant (flowering right now in Maryland!) attracts small beetles that enter the flower and stay there for quite some time. To maintain and support them while they are helping the plant reproduce, the sweet shrub flowers englobes them during parts of their flowering (this is why sometimes these flowers seem to be opening and closing throughout the day) and present small extremely nutritious structures at the base of their petals. It is on these structures that the beetles can feed on to stay strong and healthy while they are on the flowers. If you have one of these flowers in your yard, or happen to see them in one of your walks, take a second to stop and check them; you may get to meet their little beetle friends! 

Need a hand taking care of the kids? Here I am!

Some other flowers have established even more intricate relationships with their pollinators, and what they provide is not just food, but also a house! Because in these plants the offered reward is a place for the larvae of these pollinators, these interactions are called ‘nursery pollination’. Here, the pollinator visits the plants, collects pollen, and sometimes even actively places pollen on the flower tip. By doing so, the pollinator makes sure that the plant seeds develop. This is important, because their larvae will need some of them to feed on throughout their development.

yucca moth
Joshua trees (left; photo: Shawn Kinkade) are some of the most iconic plants of the US Southwest. These plants offer a brood site to their super-specialized small moth pollinators (right; photo: Judy Gallagher).

Along with this being the reward we see in a plant we love to eat (figs!), one of the most spectacular examples of the use of this reward is found in an iconic plant of the deserts of the US Southwest, the Joshua tree. Indeed, Joshua trees produce flowers that are visited by a group of moths, the Yucca moths. These moths visit the flowers, collect their pollen, and then literally push it into the flower tip to actively pollinate it. Because the moths lay eggs on the flowers, this assures that the flower develops seeds so the larvae have something to feed on. What is fascinating, though, is that these larvae never eat all the seeds, so this really is a win-win relationship between the plant and the moth.

To see how this is done, take a look at this video!

yucca moth video
Larvae of the Yucca moths feed on a Joshua tree’s seeds. To make sure that there is something for their larvae to eat, these moths actively pollinate the plants, exchanging a brood site for pollination, and in the process display some of the most fascinating behaviors one can see in pollinators. Check out the video to see it for yourself! Video: University of Nebraska-Lincoln. 

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Pawpaws: The tropical fruit from our forests

Spring is almost here and now we can start thinking about trees to plant if we did not get to that in the fall. Thinking about trees for my garden, I came back to one I have been considering for a while now — one that gives delicious fruit, is native, makes me think of tropical lands, and is not liked by deer! Today’s post is going to be about a little-known tree that’s native to our region, and whose fruits were apparently one of George Washington’s favorites: pawpaws!

What are pawpaws?

Pawpaws are trees that belong to the same plant family as chirimoyas and custard apples (Annonaceae, the soursoup family; Figure 1). From a botanical perspective, pawpaws are really special because they are the only member of their family adapted to growing outside of the tropics and able to survive our temperate climate.

pawpaw and related fruits
Figure 1 – Pawpaws (left), chirimoyas (top right) and custard apples (bottom right) are all in the same plant family, but pawpaws are the only group adapted to growing in temperate climates.

All pawpaws grow in southeastern North America, but the most common and widespread species is the common pawpaw, Asimina triloba, which is very abundant in our region. The common pawpaw is adapted to growing in well-drained and fertile habitats, such as those found in our forests. I promise you that if you ever walked in a forest in the area, you have seen hundreds of pawpaws growing in groves (Figure 2).

Pawpaw grove
Figure 2 – Pawpaws grow in well-drained fertile soils, and are common in our forests where they often grow in groves. Photo: Katja Schulz.

Why are pawpaws such a “thing”?

Besides being great native trees that grow well in our region, pawpaws have the most delicious fruits. They are considered the largest edible fruits indigenous to the continental United States. The fruits look a bit like a green mango from the outside, but are white/yellow and fleshy in the inside (Figure 3).

pawpaw fruit
Figure 3 – Pawpaw fruits are green on the outside and white and fleshy on the inside. Note the very large seeds. Photo: Elizabeth.

Their flavor is such a delicious one that I always relate it to tropical fruits. People more technical than I am in terms of flavor description say that it is a custard flavor, close to that of bananas, pineapples, and mangos. In any case, believe me when I tell you that these fruits are absolutely delightful and can be eaten fresh, in yogurts, in cakes, as jams, or frozen in ice cream!

Why didn’t I know about this before?

That was my very question the first time I tried them! It turns out that producing pawpaws for selling is not super simple. In fact, the fruits are fragile and thus can’t be transported long distances, which reduces their marketability. This means that pawpaws are usually produced and consumed locally. If you do not happen to know somebody with some trees on their land, you probably never got to try them.

Also, the pawpaw fruit season is relatively short (end of the summer), which means that one has to be in the right place at the right time to eat them. In season, pawpaws can be purchased at local farmers’ markets or on farms. You can also try to find them in the forests of the area, where you will be able to smell the sweet aroma of the fruits while you hike or bike. However, be sure to check property rules; harvesting plant materials from park lands is typically prohibited.

Why are you talking about this now? It’s not pawpaw season yet!

That is correct. However, it is pawpaw planting season now, and soon will be pawpaw pollination season, both needed to actually get the delicious fruits in the summer. So, how to plant and pollinate them?

Pawpaws can be grown from seed, but the simplest way to get one for your land is from a nursery. Several nurseries in the area sell pawpaw trees, and your best choices are those which grow trees that are adapted to your local conditions.

Pawpaws are not hard to grow and can be actually cultivated in your own back or front yard! Further, some counties and cities provide financial support to plant these native trees (see for example, Chesapeake Bay Trust and the Maryland Department of Natural Resources).

Pawpaw trees start producing fruit a couple years after planting. However, fruit production is a bit different from that of other fruits you may be growing. In fact, fruits will form only if there is cross-pollination (see this other post), since a pawpaw is not able to properly self-pollinate. This means that pawpaws need pollinators to produce fruit.

pawpaw flower
Figure 4 – Pawpaw flowers have evolved to attract and trick flies and beetles by looking dark and smelling like ripe fruits, the insects’ preferred food and egg-laying site. With this trick, the plant cross-pollinates their flowers without offering any reward to the pollinators. Photo: Judy Gallagher

Pawpaws are pollinated by flies and sometimes beetles, which the flowers attract with their maroon flowers and their ‘yeasty’ aromas (Figure 4). These scents are known to ‘trick’ the pollinators into visiting the flowers, mimicking the odor of ripe fruits that these insects prefer to feed on or lay their eggs. Flowers then attract these pollen dispersers, who, while visiting the flowers, will cross-pollinate them without their will.

You can imagine by now that having more than one pawpaw on your land or in the surroundings of your house will increase fruit production. It will then be more likely that the fooled pollinators will have visited another plant and thus carry pollen when they visit your tree.

Alternatively, if you would like to be absolutely sure to get a good pawpaw crop, you can cross-pollinate them by hand. To do that, get a small brush, pick pollen from the anthers of one flower (check the drawing here to find them), and transfer it to the stigma of another. That way you will get to live your best pollinator life! 😊

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park. See more posts by Anahí.

Helen’s flower hails pollinators

common sneezeweed flowers
Helenium autumnale. Photo: Beverly Turner, Jackson Minnesota, Bugwood.org

Helen’s flower is an underdog when it comes to native plants. It is not as well known or as popular as butterfly milkweed, bee balm, or black-eyed Susans — but perhaps it’s time for its day in the sun. It makes a nice addition to a pollinator garden.

Helenium autumnale is the species name of this North American native perennial plant. It goes by the (somewhat unfortunate) name of “common sneezeweed” because dried parts of the plant were formerly used for making snuff to induce sneezing. As an ornamental garden plant, it is not known to prompt sneezes from pollen dispersal (it relies on insects for pollination) and I prefer to address it by its lovelier common name, Helen’s flower… or just plain Helenium.

Wild Helenium autumnale boasts cheerful yellow button-like flowers tended by a skirt of turned-down petals in late summer to fall. Its natural habitat in Maryland includes swamps and moist riverbanks, so in your garden, it will like a location where it has some regular soil moisture. It can grow in full sun or partial shade and stretches in height from 2 to 5 feet tall. The flowers support a variety of pollinators such as bees, wasps, syrphid flies, butterflies, and beetles.

A wide variety of cultivars of Helenium are now available. They range in color from bright canary yellow to orange and crimson and various combinations in between. Many of the cultivars tolerate drier soil and have a more compact habit.

Mt. Cuba Center in Delaware conducted field trials of 44 Helenium species and cultivars from 2017 to 2019. They evaluated plants for their habit, vigor, disease resistance, floral display, and pollinator visits.

helenium flowers in a garde
Helenium flowers in a garden, “The warm glow of early Autumn” by hehaden, Flickr

Given the high interest in pollinator gardens right now, I was curious about their observations of pollinator visits in particular.

The native Helenium autumnale had the most observed pollinator visits (162), while the cultivar H. ‘Zimbelstern’ came in second (151). Both of these had excellent powdery mildew resistance as well. Other cultivars such as Helenium autumnale ‘Can Can’ and H. ‘Tijuana Brass’ also had excellent ratings for these two characteristics. The best performers in the study overall (considering all the characteristics evaluated) were ‘Kanaria’, ‘Zimbelstern’, and ‘Can Can.’

The native Helenium autumnale had the most observed pollinator visits (162), while the cultivar H. ‘Zimbelstern’ came in second (151).

For all the details and results of the evaluation, read the report online.  

If you plan to start (or add to) a pollinator garden this spring, do consider adding Helen’s flower if you have a moist site in full sun or partial shade. Mt. Cuba’s report provides good information on plant care, including staking and pruning tips and recommendations for managing the two most common diseases — powdery mildew and aster yellows.

To purchase plants, check the Maryland Native Plant Society’s website for spring native plant sales and nursery sources.

Visit the Home & Garden Information Center website for additional resources on native plants and gardening for pollinators.

By Christa K. Carignan, Coordinator, Digital Horticulture Education, University of Maryland Extension Home & Garden Information Center. Read additional posts by Christa.

Serpentine soils are anything but barren: They support a unique grassland habitat

I have never been to the African grasslands, where lions, zebras, elephants, and wildebeests seem to be in continuous danger. I have, however, been to a Maryland habitat that few people know about, and that, even though lion-, zebra-, elephant- and wildebeest-less, reminded me strongly of those African savannas.

This habitat I am talking about is the Serpentine Grasslands (or Barrens) of the Eastern United States. If you have never heard of them, fear not! Hopefully, by the end of today’s post, you will know a bit more about them and you’ll even try to go visit the few remains that still exist of this beautiful but endangered habitat of our region.

Serpentine Barren Grassland
Fig. 1 – The Serpentine Grasslands of Maryland at Soldiers Delight. Photo: U. Weber.

As you may have guessed from its name, Serpentine Grasslands or Barrens are prairies where the dominant plants are grasses. This is all good, but if they are grasslands, why are they also called Barrens, you may be asking yourself. The answer to that question is what in my opinion makes these habitats so fascinating; something that is also hidden in the other part of their name: “Serpentine”. Indeed, the word Serpentine refers to the type of soil these grasslands are on.

Serpentine soils form on a type of bedrock called serpentinite. This type of rock only exists in places where tectonic plates come into contact, fold, and volcanic activity occurs. This happened in our area about 480 million years ago when the Appalachian Mountains formed. Because of this, there is now an arc of serpentinite present in the Maryland-Pennsylvania area, parallel to the mountains.

Serpentine Soil
Fig. 2 – The Serpentine Grasslands have usually bare soils that have a greenish tint, due to the serpentinite they originate from. Photo: A. Espíndola.

Serpentinites are rich in many metals and other compounds that make the soils that form on top of them relatively toxic and unfriendly to many plants. Because not many plants can grow on these soils, not much soil is retained and the ground ends up being rocky. Because of this characteristic, places with these soils are not very fertile, and, when the Europeans arrived in the area, they started referring to them as ‘barren’, since they were not only infertile, they also had no timber on them. However, even though they were referred to as barrens, many plants do grow on these thin soils, and actually, many of Maryland’s rare flower plants and grasses are adapted to grow in this habitat!

Indeed, the Serpentine Grasslands of Maryland and Pennsylvania are some of the unique places where it is possible to find, for example, the rare moss pink, serpentine aster, or the sandplain gerardia (Fig. 3). It is also home to several endangered and rare species of butterflies and moths such as the Dusted or the Cobweb Skipper (Fig. 4).

Even though the plants and butterflies present in this habitat are relatively well-studied, we still know very little about what other organisms live in the grasslands. To remediate this, in my lab at the University of Maryland in College Park, we are working on trying to understand better what species of insects are present in the area.

Plants of the Serpentine Barron
Fig. 3 – Many rare plants are present in the Serpentine Grasslands of the Eastern US. For example, the moss pink (left; Photo: J. Gallagher) and the sandplain gerardia (right; Photo: A. Espíndola).

For the moment, we are focusing on insect pollinators, and our first works indicate that the plants growing in these grasslands are pollinated not only by bees but also by hoverflies, showing how important these lesser-known pollinators may be to sustaining a very rare habitat of our region. (Take a look here to learn more about hoverflies as pollinators.

The Serpentine Grasslands had not always been rare and endangered. Indeed, serpentine soils extended for quite an area in the Maryland-Pennsylvania region. So, what happened to this habitat that made it so rare today? Ecologists and historians can help us with this.

Like many habitats dominated by grasses, Serpentine Grasslands need fire to sustain themselves. In the absence of fire, pines and red cedars from the surrounding areas start establishing in the grasslands and compete with the grasses and all the rare plants, making the once grassland become an encroached pine forest. When the Europeans first arrived in our region, documents said that there were Serpentine Grasslands that extended for at least 130,000 acres. Today, Serpentine Grasslands occupy about 1.6% of that area.

These grasslands were managed as hunting grounds by several tribes (Susquehannock, Shawnees, Lenape Delaware), who burned them regularly to maintain the grasses and attract large herbivores to hunt. These tribes had complex systems of rights over these lands, which they shared with neighboring tribes as needed. Records show that these extensive grasslands were extremely rich in fauna. There were a myriad of birds (mentioned in some records to ‘have darkened the sky’ when migrating!), wolves, bears, cougars, deer, and buffalo roaming these regions!

European colonizers quickly realized that these grasslands were great land for cattle and hunting, and thus started settling and claiming the native tribes’ lands. However, the new inhabitants did not continue the practice of burning, which led to the habitat starting to degrade and finally becoming less appropriate for cattle and cropping.

Eventually, these lands were relegated as ‘useless’ lands and were thus prime land for building or just reinvaded by pines and other trees, which were used for timber. I sometimes try to imagine what these lands — today just 30 minutes away from my house — may have looked like with those large fascinating animals living right here.

Dusted Skipper
Fig. 4 – The Serpentine Barrens are the habitat for several rare moth and butterfly species, such as the Dusted Skipper (Photo: A. Wells).

Today, the Serpentine Barrens are protected and managed with fire in several parts of the state. A large part of these protected lands are not open to the public. However, we are lucky that some places are indeed accessible to the public and can be visited throughout the year.

The largest remnant of Serpentine Grasslands on the Eastern Coast of the US is west of Baltimore, in the Soldiers Delight Natural Environment Area. Another public land where some remains of Serpentine Grasslands are still visible is in Northern Baltimore, at Lake Roland Park.

I am lucky enough that I can visit and work in these fascinating places. If you have never been to them and would like to see these local jewels, take me up on the invitation and consider hiking some of their trails. The spring and summer are gorgeous on these lands, and who knows, you may be lucky enough to see one of those rare beauties that still live there!

By Anahí Espíndola, Assistant Professor, Department of Entomology, University of Maryland, College Park