Spring – Maryland Grows

Waiting on Spring Garden Cleanup to Support Beneficial Insects

April 15, 2024April 15, 2024Maryland Grows2 Comments

With warmer temperatures and spring blossoms we are likely ready to get back into our gardens. Before we get our hands dirty, let’s learn how to support the beneficial insects in our landscapes that are and will be emerging from their overwintering sites. In today’s post we will review some information and tips on how we can support, and not disrupt, the life cycles of beneficial insects like our native bees, when we do any spring garden cleanup or prep.

Plant stems, leaves, and other debris can be home to many beneficial insects during the winter months that are waiting on warmer days before they emerge this spring. Wait as long as you can before removing any plant materials. Photo: M.E. Potter, University of Maryland Extension

Overwintering beneficial insects

Some insects migrate (e.g. Monarch butterfly) to avoid the cold temperatures, but there are many insect species that overwinter (spend the winter months in one of their life stages- egg, larva, nymph, pupae, or adult) in Maryland. Insects like luna moths (Actias luna) who overwinter in the pupal stage in cocoons within leaf litter (see photo below), the great spangled fritillary (Speyeria cybele) who overwinters as caterpillar larvae in leaf litter, bumble bee (Bombus spp.) queens who can overwinter as adults underground, small carpenters bees like Ceratina strenua who overwinter as adults in plant stems, and praying mantids like the Carolina mantis (Stagmomantis carolina) who overwinter in the egg stage as ootheca (an egg case) laid on woody plant stems and other structures. All these examples are of beneficial insects, who provide services like pollination and pest control during their active life stages. This goes to show, even in the cold and quiet winter months, your garden can be full of life!

a luna moth cocoon found in fallen leaves — *Luna moths overwinter as pupae in cocoons made of fallen leaves and silk. In late spring the insect will emerge as an adult moth. Photo: M.J. Raupp, UMD*

When is too early for spring cleaning?

Generally, the longer you can wait the better! Insects do not all emerge at the same time. There are some native bee species that emerge from their overwintering sites as early as March (e.g. some Colletes spp.) and some that typically do not emerge until late May (e.g. Blue-green sweat bees). Due to the changing climate and the diversity of insect life cycles, we unfortunately cannot point to a specific date on the calendar to know all the overwintering insects have emerged from our green spaces. We can look for different cues in our environment to hint at insect emergence.

Before last frost and consecutive warm days

Once we are out of risk of evening frosts and daytime temperatures are consistently above 50°F for several days in a row, many insects will begin to emerge. Otherwise leaf litter and other plant debris are vital for overwintering insects to survive the cooler temperatures. With climate change, and the chances for more drastic temperature changes, fallen plant material becomes even more important for protecting overwintering insect populations. Think of a fallen leaf as a blanket for our beneficial insects!

Looking for spring blooming trees like cherry, peach, or eastern redbuds can clue us in on this year’s seasonal changes and timing when it comes to insect emergence. Once fruit trees have finished blooming, many of our overwintering bees and beneficial insects have likely emerged. Photo: Nancy Lee Adamson, Wild Bee Plantings

Before fruit trees bloom

Many of our fruit trees (along with natives like Eastern redbud and red maple) bloom in early spring, providing nectar and pollen for our early riser pollinators; check out the figure below on native bee and orchard bloom phenology. If you wait for any garden cleanup until these trees have finished blooming (around mid-May), many of our insects will have likely emerged by then. Since phenology (seasonal changes in a plant’s life cycle, such as the timing of bloom) can shift with changing climate conditions, always keep an eye on the trees and blooms around you. A great excuse to get outside and get to know your local plant life.

Before consistent lawn/turf growth

Noticing consistent lawn/turf growth in your area? Cool-season grasses begin their spring growth once soil temperatures are between 50° and 65°F. A general guideline is once lawns need to be mowed it is a good sign it has been warm enough for many of our overwintering insects to emerge. If you have lots of lawn in your space, consider reducing and replacing the lawn with beneficial insect friendly native plants! If you are wondering what you could plant instead, check out Lawn Alternatives. And if you have heard of No-Mow May, check out the Pros and Cons of the No-Mow May Movement and the Controversy Surrounding No Mow May, by Dr. Gail Langellotto.

Sometimes less is more

Less garden cleanup can have a positive impact on beneficial insect populations! Rethink removing plant debris in certain areas of your landscape. Unless the plant debris comes from a diseased or pest infested plant, leaves, stems, sticks and more can be left, relocated, or reused as wildlife habitat. Your plant debris is some animal’s home! Preliminary data from a study conducted by Max Ferlauto, PhD student in the Burghardt lab, at the University of Maryland, Department of Entomology, shows the number of emerging moths and butterflies are reduced by approximately 67 percent in areas where leaves are removed. If you are removing any plant material, consider relocating the materials to an unmanaged, “habitat area”, or to a compost pile after late spring.

Help fight climate change’s impact on beneficial insects by providing shelter to help insects withstand adverse conditions. Consider leaving and/or adding one or more of the following sources of habitat in your green space this spring!

Leaves
Flower stalks/plant stems
Fallen/removed twigs
Wooden logs
Rocks/rock piles

From “messy” to sustainable

If you are worried about your space looking messy from less spring cleaning, there are ways to get creative to transform your and the public’s view of your conservation areas. An opportunity to personalize your green space with unique and practical “signs of care” (also known as “cues to care”).

Signage

A sign in your green space can not only enhance the look but also help educate others. Why are you leaving the leaves? Let others know by adding a sign about how leaves support native wildlife. Look to local artists and organizations to find a sign that works for your space and could convey a science-based message. You can earn a sign from our Bay-Wise Master Gardener program once your landscape is Bay-Wise certified. To learn more, check out our Bay-Wise program page.

Fencing or edging

Even a short fence or edging can make a space look purposeful and cared for. Edging can be made out of repurposed materials (pebbles, stones, sticks, even glass bottles) or can be purchased from most gardening centers or hardware stores. Think of it as putting a frame around the artwork and beauty that is your garden. For ideas check out, Edging Makes Landscape Beds Pretty, Easy to Keep or Landscape Edging Materials.

Tidy, accessible paths

Ensure any pathways, especially areas around public sidewalks, are clear so all can access and enjoy the space and surrounding area. Cut back overgrown plants that may be blocking or obstructing pathways. If you are working in a community garden, consider the accessibility of your landscape so we may create more inclusive green spaces for all. To learn more about accessible green spaces, check out these pages, Create an Accessible Garden for Those of all Physical Abilities and Gardens Are For Everyone: Ideas for Accessible Gardening.

Additional resources

By Madeline E. Potter, M.S.,Faculty Specialist for Entomology and Integrated Pest Management, University of Maryland Extension

Delicate Wildflowers Signal Spring

April 13, 2024April 12, 2024Maryland GrowsLeave a comment

Each spring I delight in my first glimpse of dainty spring wildflowers scattered along my hiking trails. Welcome, friends.

Called spring ephemerals, these native wildflowers emerge when the sunlight hits the woodland floor before the first tree leaves unfurl.

They are called ephemerals because their beauty is fleeting. They come and go in just a few short weeks, dissolving back into the ground in late spring or early summer.

Why? They must bloom, be pollinated and set seed before the tree canopies steal their sun. But oh what a show until then.

It starts with a dusting of tiny pink-striped spring beauties (Claytonia virginica). Time rolls back as I remember the lawn of my childhood home awash in pink. Even their pollen is pink.

a single blossom of spring beaty peeping through a leaf — Spring beauty *(Claytonia virginica).* Photo: R. Rhodes, University of Maryland Extension (UME)

Among the beauties, Dutchman’s breeches (Dicentra cucullaria) pop up here and there looking like someone left white pantaloons out to dry.

Intermingled are the nodding white bell-like blooms of cutleaf toothwort (Cardamine concatenata).

Boldly marching through the waves of more delicate wildflowers are the hefty trillium, named for their trio of pointed flowers and leaves.

I’m partial to the splotched leaves and red-brown flowers of toadshade (Trillium sessile) but there are lovely purple- and white-flowered forms.

I also am partial to these wildflowers’ poetic names: spring beauties, Dutchman’s breeches, toothwort, toadshade, and trillium.

In my own garden, I’ll smile over a sweep of bloodroot (Sanguinaria canadensis). Its white many-petaled blooms dance in the slightest breeze over large hand-like leaves.

a group of bloodroot flowers in bloom — Bloodroot *(Sanguinaria canadensis*). Photos: C. Carignan, UME

bloodroot flowers opening — Bloodroot *(Sanguinaria canadensis*). Photos: C. Carignan, UME

And don’t get me started on my mayapples (Podophyllum peltatum). Dangling a single lovely white flower, their splotched umbrella-like foliage hangs on until mid-summer.

mayapple flower — Mayapple *(Podophyllum peltatum)*. Photo: K. Baligush, UME

But wait. There’s more.

Virginia bluebells (Mertensia virginica) are just starting to edge the trails with a froth of blue and pink. My father’s favorite, they show pink in bud, then open fistfuls of sky blue bells.

close up of Virginia bluebell flowers — Virginia bluebells *(Mertensia virginica)* are lining many local woodland trails. Photo: Joan Willoughby

All spring ephemerals grow low. Since they must withstand early spring vagaries of weather, they must be tough. Growing low protects them from fierce winds.

I encourage you to bend low for a closer look. Most ephemerals have delightful details you don’t notice from on high such as pollen held at the bunched bottoms of Dutchman’s breeches.

How can these spring ephemerals look so good so early? Most have thick rhizomes (thickened underground stems) or bulbs that hold energy stockpiled from the previous year.

Ephemerals’ enduring qualities mirror their ecological benefit. As native plants, they naturally support a healthy ecosystem and provide vital pollen and nectar to early native beneficial insects.

I hope I’ve inspired you to look for wildflowers on your walks and consider adding some to your landscape. But please don’t harvest them from the wild. Look for them at native plant sales and in seed or plant form in catalogs.

Happy wildflower hunting.

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.

Q&A: What can I do about rust fungus on my juniper?

March 17, 2023March 16, 2023Maryland GrowsLeave a comment

A rust gall on juniper with spore “horns” just starting to emerge. As soon as it rains after this point, the “horns” turn gelatinous and bright orange. Photo: M. Talabac

Q: I heard rust fungus can infect junipers but they aren’t worth spraying to treat. Is there anything else I can do to reduce the fungal spread from them to my other trees?

A: If you see and can reach fungal galls on the branches, clip them off. Some rust fungi (though not all) create a gall on their juniper hosts. Plant galls are tumor-like in that they’re clusters of malformed tissue, often in response to a pest or (in this case) an infection. When the weather starts to be consistently mild in spring and we receive enough rainfall, the galls where the fungus is spending the winter will begin to exude their spores.

These rust spores blow on the wind or wind-driven rain to vulnerable host plants like various members of the rose family. In our gardens, this includes apples and pears, hawthorn, serviceberry, quince, and crabapple. Fungus spores are extremely tiny, so how will you know what to look for? If the gall is producing orange goo, you’re missing the window since spores are already being dispersed. Ideally, remove all visible galls before this point, while they’re still hard and dry. Now is an excellent time to inspect junipers on your property for galls. Trim them off with hand pruners and toss them in the trash (don’t compost).

This is not a foolproof method for eliminating the risk of rust infection on other plants this year, but it certainly could help reduce the disease pressure. Fortunately, infections like cedar-apple rust, while an aesthetic nuisance from time to time, generally don’t cause serious damage to all hosts, though they can be more serious for some, like apple.

Find photos and more information about Rust Diseases of Trees on the Home and Garden Information Center website.

By Miri Talabac, Horticulturist, University of Maryland Extension Home & Garden Information Center. Miri writes the Garden Q&A for The Baltimore Sun and Washington Gardener Magazine. Read more by Miri.

Have a plant or insect question? The University of Maryland Extension has answers! Send your questions and photos to Ask Extension. Our horticulturists are available to answer your questions online, year-round.

Early Spring Lawn Tips for Fertilizer and Pre-emergent Timing

March 13, 2023March 10, 2023Maryland Grows7 Comments

Speedwell is a winter annual weed. It will end its life cycle and die naturally once we have consistently warm temperatures. Photo: G. Rinehart

The warmer-than-normal weather during February had many people thinking about an early start to lawn and garden season. However, as temperatures have dropped and been below normal for much of March, it looks like we may have a couple more weeks before lawns really start growing. Lawn growth and crabgrass emergence are related to soil temperature, which is slower to change than the air temperature. While I have heard reports of soil temperatures topping out in the mid-50s for a day or two, it’s important to remember that in order to germinate crabgrass needs soil temperatures around 53-55⁰ F sustained for 5 days. These two things lead to a few questions, particularly pertinent this year when February felt like March and now March feels like late February.

Should I fertilize my lawn now?

While the legal window for applying fertilizer to lawns in Maryland began on March 1, that doesn’t necessarily mean you should fertilize your lawn just yet. Unless the grass is actively growing (which is dependent on warmer soil temperatures) it likely won’t take up and use the fertilizer—so you are better off waiting until the lawn is actively growing. Temperatures consistently around 60 and enough growth to warrant a second mowing are pretty good indicators of this. Keep in mind that if you fertilized your lawn in the fall you can probably wait until after the “flush of growth” in the spring (usually April/early May) and then schedule your spring fertilizer application for after that “flush” and leading into summer—usually around mid-late May. If you didn’t fertilize last fall it is tempting to try to “jump-start” the lawn in early spring with a fertilizer application, but hold off until the soil temperatures are consistently warmer and highs are around 58-60⁰ F on a regular basis.

Should I apply crabgrass pre-emergent now?

I would wait until soil temperatures are 53-55⁰ F sustained for 5 days. Keep in mind that your best defense against crabgrass is a dense turf that crowds out crabgrass seedlings. So, if you have good turf density and mow at 3” or higher, your overall crabgrass pressure should be lower anyway. The typical recommendation is to wait until the forsythia is “half green-half gold” (or even a little earlier), but with the warm February we had, that indicator may or may not be as accurate this year. You can check soil temperatures for your location at the following website: https://www.greencastonline.com/tools/soil-temperature.

Is there harm in applying crabgrass pre-emergent too early?

Probably not, unless it’s applied several weeks early and the product starts to break down before crabgrass even starts germinating. If you want to maximize the period of time your crabgrass application is effective, wait until when conditions are conducive to crabgrass germination and then apply it.

grassy lawn weed called roughstalk bluegrass — Roughstalk bluegrass *(Poa trivialis)* is a cool-season weed that shows up in early spring. If you only have a few patches, you can dig them out by hand (including the roots) and overseed to fill in the bare spots. Photo: G. Rinehart

On another note, this is now the time of year when many winter weeds become more noticeable as they are likely producing flowers and setting seeds. While you can apply selective products to control these weeds, remember that these winter annuals like chickweed, purple deadnettle, speedwell, henbit, etc. are almost at the end of their lives and will die naturally once we have consistently warm temperatures. Another weed often noticed this time of year is the grassy weed called roughstalk bluegrass (Poa trivialis). Seeds of this grass are often a contaminant in turfgrass seed mixes (the cheaper the seed, the more likely you will have weed seeds) and this grass starts growing much earlier than tall fescue. As the temperatures warm, it is not as aggressive and noticeable. There are few selective control products that are labeled for roughstalk bluegrass and they tend to be restricted to professional sites and/or are expensive. If you only have a few patches in your lawn, digging these out (including the roots) and then re-seeding the spot with a soil-tall fescue mix is the best control approach for most homeowners.

By Geoffrey Rinehart, Lecturer, Turfgrass Management, Institute of Applied Agriculture, University of Maryland. Read more articles by Geoff.

The value of a pile of sticks in your yard or garden

March 10, 2023March 13, 2023Maryland Grows18 Comments

With spring coming up, many of us are already starting to get our yards and gardens ready for the growing season. Among the activities we may take on, there can be the managing of branches, sticks, and wood that may have been trimmed from trees and shrubs in the fall, over the winter, or just recently. In today’s post, I want to talk about how to integrate these resources into our green spaces, to support wildlife and the natural services they provide.

a pile of stick in a yard — Wood and stick piles can provide welcoming habitat to beneficial organisms. Photo: A. Espíndola

Increasing the diversity of our green spaces

In several of the posts that we publish on this blog, we recommend different actions that can be taken to increase biodiversity in our green spaces (see local ecotype plants, helping pollinators in small green spaces, and conserving parasitoids for some ideas). We know that increasing biodiversity improves the ability to control and restrain pests, increases wild and crop plant pollination, and in many cases leads to better soil quality. Among these practices, there is one that increases the physical complexity of our green spaces, providing nesting, shelter, and food resources to beneficial organisms. The practice I’m talking about consists of building wood and stick piles that can be established in our green spaces. The idea behind this practice is to create a space where birds, small mammals, insects, and even pest predators can find their preferred resources, and thus be attracted and present in our environments (learn more about the landscaping rationale for using dead wood).

What organisms are attracted by these piles?

Depending on the size of the pile and its composition (e.g., large logs, smaller sticks, a mix of them), different organisms will be attracted and may establish themselves in our green spaces. The presence of a mix of logs and sticks usually attracts birds, which may nest within the pile or may just spend time within the pile searching for food or finding shelter at different points during the day. These birds will certainly contribute to increasing the diversity of animals present in our green spaces and can also in some cases participate in the control of insect pests that we may not want in our gardens and yards.

Carolina wren bird with a caterpillar in its mouth — Carolina wrens are very attracted to shrubby habitats, meaning that piles of wood and brush represent a great way to provide resources to these little cute birds who in turn can help us keep herbivore populations in line. Photo: Shenandoah NP.

Other animals we can observe in these piles are a variety of insects then may be associated with the decomposition of wood or that may use wood as a nesting or overwintering resource (e.g., bees, solitary wasps). While the former can help recycle the wood material and reintegrate it into the habitat, the latter may participate in the pollination of plants and crops that we may grow in that area or predate on unwanted pests.

Similarly, ground-dwelling invertebrates like millipedes and ground beetles can also find shelter under these piles, while the brush can also contribute to the nesting of pollinators such as (ground-nesting) bees, the overwintering of some butterflies and moths, and help improve the quality of the soil in that part of our yard.

Larger organisms may also be attracted to these piles, such as small mammals, amphibians, and even reptiles. Although we may tend to dislike these groups of animals, many of them feed on unwanted soil organisms and may help with soil quality, while others can actually control vermin through their predatory abilities. This is particularly the case of snakes that may find shelter in these spaces, which, while harmless to humans (the vast majority of snakes in Maryland are non-venomous, readily feed on rats and mice that may be present around the house.

a pile of wood branches and sticks in a yard makes a habitat for beneficial organisms — A mix of thick and thin pieces of wood can provide a diverse habitat to many different organisms. Photo: A. Espíndola.

How to build these piles?

These piles can take many different shapes and sizes, which depend in part on the materials and space available. When very large spaces are available (e.g., in the woods), it is recommended for these piles to be relatively large – at least 10 to 20 feet in length, and up to 8 feet in height (read more about these larger brush piles). In smaller spaces such as in urban or suburban gardens, these piles can be much smaller, occupying areas that may not be regularly used for other purposes. In all cases, it is ideal to build these piles using a combination of different types of materials, such as twigs and branches of different thicknesses, some logs, and even some branches that may still have dead leaves attached to them…always using healthy materials.

An important consideration when putting together these piles is that they should not be built leaning on or very close to wood-based structures or the foundations of our buildings. This is because of the potential risk of termite infestations of buildings if the piles are not physically separated from them. However, it is important to stress that establishing these piles has not been shown to be associated with higher termite infestations if the pile is not in contact or very close to the built structure. (You can read a very good discussion about mulch and termites from Iowa State Extension).

So, as you work on your spring garden, I encourage you to think about plant stems, logs, and branches not as waste that needs to be cleaned up, but as beneficial resources that you can incorporate into your available space.

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

Anahí also writes an Extension Blog in Spanish! Check it out here, extensionesp.umd.edu, and please share and spread the word to your Spanish-speaking friends and colleagues in Maryland. ¡Bienvenidos a Extensión en Español!

Container Gardening with Ashley Bachtel-Bodkins – The Garden Thyme Podcast

May 16, 2022May 16, 2022Maryland GrowsLeave a comment

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In this month’s episode, we are talking about container gardening with Ashley Bachtel-Bodkins, Senior Agent Associate and Master Gardener Coordinator for the University of Maryland Extension in Garrett County. If you are limited on space and time, a container garden may be a perfect way to add in the garden you’ve always wanted. We talk about picking the correct size container for your plant needs, drainage tips, and growing media.

We also have our:

Native Plant of the Month (Sweet Bay Magnolia, Magnolia virginiana ) at 26:00
Bug of the Month (Spongy moth, Lymantria dispar) at 30:45
Garden Tips of the Month at 38:45.

If you have any garden-related questions please email us at UMEGardenPodcast@gmail.com or look us up on Facebook.

The Garden Thyme Podcast is brought to you by the University of Maryland Extension. Hosts are Mikaela Boley, Senior Agent Associate (Talbot County) for Horticulture; Rachel Rhodes, Agent Associate for Horticulture (Queen Anne’s County); and Emily Zobel, Senior Agent Associate for Agriculture (Dorchester County).

Theme Song: By Jason Inc

Spring Ephemerals – The Garden Thyme Podcast

April 18, 2022April 15, 2022Maryland GrowsLeave a comment

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April is National Garden Month! So Happy National Garden Month everyone. One of the clearest signals of spring is the emergence of spring ephemerals — daffodils, crocus, tulips… these bulbs are some classic examples — but we have so many more to enjoy! Our woodland wildflowers may be more subtle, but are no less impressive and are even more rewarding. This month we take a break from our garden and all the spring chores to talk about some of our favorite woodland spring ephemerals.

Ephemerals covered in this episode include Dutchman’s breeches, Virginia bluebells, mayapples, bellworts, spring beauty, Jack-in-the-pulpit, and pink lady slipper.

We also have our:

Native Plant of the Month (Sessile trillium) at 22:15
Bug of the Month (Termites) at 25:35
Garden Tips of the Month at (36:55)

If you have any garden-related questions please email us at UMEGardenPodcast@gmail.com or look us up on Facebook.

Theme Song: By Jason Inc