Food Gardening

Making Plans for Spring Seed-Starting

Maryland Grows5 Comments

Do you want to learn how to start your own seeds for garden transplants? Did you just look at the title of this post and say, wait, it’s December, why would I be thinking about this now? If your answers are ‘yes,’ then read on.

Pepper and tomato seedlings growing under LED lights, in plastic pots set respectively in a heavy-duty seed tray and an old baking pan

You begin to think about seed-starting in December rather than in March because it’s always better to hit the ground running. This is especially true if you’re new to the process. If you wait until it’s seed-starting time to start gathering your equipment and figuring out how to make it all work—and you’re also trying to prep a garden for growing—you are going to be stressed out. Spend a little time this month considering your upcoming needs (maybe even put a few items on a gift list?) and then you’ll have plenty of time to get organized.

We have a great guide to seed-starting on the HGIC website. But no guide can cover everything, and I generally find they don’t start with the absolute basics. The first question to ask isn’t “What kind of lights should I use?” or “What seeds should I start and when?” The first question is “How do I make this work in my own home?”

Location, Location, Location

Where should you set up your lights, and how much space do you need? I bet if you asked a bunch of gardeners (and their patient spouses) where seed-starting belongs, about 90% of them would say “the basement.” But of course some of us don’t have basements, and some basements are cold and damp, or are full of stuff, or are just not a place we like going. If you have a pleasant finished basement, with heating, that is not constantly occupied by teens playing video games, it may be the ideal space. But don’t begin with that assumption.

Here are some needs of a seed-starting spot to consider:

  • Comfortable temperature. Whatever level of heat you prefer to live in is probably fine for young plants, but you really don’t want to force them to grow in the cold. There are ways to warm them up, but why not give them what they need to begin with? Chilly basements are for storing root vegetables and wine, not for persuading tomatoes to germinate.
  • Access to electrical outlets. Gotta plug in those lights. Make sure you’re not going to trip a circuit breaker. Or trip over too many extension cords.
  • Access to water. It’s good to have a sink nearby so you don’t have to carry water too far. Also handy for washing pots and seed flats.
  • In sight, in mind. The more often you look at your plants, the more likely you are to catch small problems before they become large ones. Don’t hide them away in the most inaccessible corner.
  • Enough space. I advise beginning seed-starters to start small, but of course you’re not going to take that advice. (I mean, I didn’t.) Read the sections about lights and furniture below while you’re considering, and try not to plan for more plants than you can fit in your garden. But do remember that plants seeded into small cells may need to be transplanted into larger pots before going into the ground. Better to grab all the space you can for this project even if you don’t think you’ll use it all. You will never have enough, mwhahaha.
  • Protection from small friends. Make sure your seedlings aren’t going to be uprooted by curious toddlers, or chewed on by pets (you should see the elaborate fence I use to keep my cat from eating my pepper plants), or chewed on by animals that are not pets.
  • Protection from annoyed spouses or others who share your home. The lights will be on for at least 16 hours a day. This may or may not coincide with everyone’s sleep schedule.

There. Whatever room you are now picturing, that is the room you are going to use. Think outside the basement. You can make it work.

Plants Are Furniture

Seed-starting trays do not float in mid-air, so you’ll need something to support them. In the basement, this might be an ugly utility shelf; in the living room, you’ll want something a little more attractive. There are about a million ways to set up your growing space, and if you want to spend money, there are plenty of companies ready to sell you an entire growing system. But you can assemble the components yourself for much less. I recommend a wire shelving unit in a color that works with your décor. Or maybe you already have shelves or counters that will be perfect. Just remember three things:

  1. You need to be able to hang (or otherwise install) lights above the plants, and they need to hang from somewhere (this is why wire shelves are great).
  2. The distance between a light and the top of a plant should be approximately two inches. Plants will start tiny and may reach a foot tall before you scurry in a panic to find another place to put them until it’s warm enough to plant them outside. This means that either the lights need to be adjustable or the plants need to be raised up by sitting on something when they’re small. It also means the shelves need to be an appropriate distance apart (but not necessarily all the same distance; remember you can shift trays around depending on stage of growth).
  3. Everything must be waterproof. I probably should have put this into the location section, but I didn’t want to scare you. You can put down very tasteful plastic sheeting.

Let There Be Light

HGIC also has a page on lights for seed-starting. Here’s my additional advice:

  • Get the best lights you can afford. If you decide to give up seed-starting later on (but give it at least two years!), you can always sell them. I have switched to T5s for half of my seed-starting arrangements, and they make a huge difference in size and growth rate of seedlings.
  • LEDs are another possibility that is growing in popularity and availability. You don’t need the fancy blue and red ones for starting seedlings (those are for growing pot plants that need to flower); you can get white LED shoplights, which are slim and nice-looking and will do fine in the living room. They are pretty bright, so add “where they won’t shine in my eyes” to the location criteria. This is the best explanation I could find of why and how to choose LEDs.
  • One of the reasons I bought my LED shoplights is that they are three feet long and thus fit my three-foot wire shelving unit. Trying to make four-foot lights fit a three-foot shelf is a geometric challenge. Same with two-foot lights, which I also acquired some of along the way.
  • Buy a timer (the kind you use with lamps to fool burglars into thinking you’re not on vacation) and figure out how it works before you need it. Sixteen hours a day is minimum for healthy seedlings.
  • Other items for your list: a power strip, and hooks and chains to hang the lights as needed.
  • If you want even more detailed information about growing under lights, this podcast episode is useful.
Wire shelving unit with hanging lights. This was in the geometric challenge days, fitting four-foot and two-foot lights into a three-foot shelf.

Buy More Takeout

You will need to start your plants in something. More on that in a later post, but for now you might want to be saving your plastic takeout containers (rectangular is more efficient than round), yogurt pots, and salad clamshells. Or you can browse some good garden supply catalogs and websites to see what’s available. It may be possible to get away from plastic altogether (I’m trying) but not in a cheap or practical way yet, so focus on reuse and/or durability. Hint: if you feel you might be committed to this hobby, and you want standard-size seed-starting trays (usually 10”x20”), find the heavy-duty plastic ones that will last decades with care, rather than the cheap kind that crack after a couple of years of use. I asked for the former as a Christmas gift a few years ago (much better than perfume!). But I also know exactly how many pots of all the different volumes fit into a black rectangle that once held moo shu pork. Mini-trays like that also arrange themselves more flexibly under lights than large trays.

Seedling pots nestled into plastic takeout containers and styrofoam mushroom containers

Let’s pick this discussion up in January! Meanwhile, start browsing those seed catalogs.

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

Cleaning up the vegetable garden in fall

Maryland Grows2 Comments

With the first frost of autumn hitting many areas of Maryland, this is a good time to think about cleaning up your vegetable garden, if you haven’t already done so! Below are some hints to getting this job done efficiently and well, and some distinctions between the vegetable garden and the rest of your yard to keep in mind.

First, maybe you still have seasonally-appropriate plants growing – in which case, congratulations! Whether they are cover crops or cool-season vegetables, keep them watered as needed and remove weeds. We’re past the point where you have to worry about most insect pests, so the lightweight summer row covers can come off the brassicas, but you may want to replace them with heavier row covers to keep the plants a bit warmer and protect them from wind. You’ll have less frost damage that way, and can keep your veggies alive longer into the winter.

Summer vegetables, however, are toast. In some recent years we haven’t had frost until later in November, and I’ve seen lots of gardeners keep tomatoes and peppers growing up to Thanksgiving. My attitude is, why bother? You may still get some produce, but the quality and flavor will not be great, and then you’ll have to do cleanup when it’s really cold. Just pull the plug. Of course I have a small garden, and if I want to plant any fall veggies, the summer ones must vacate as soon as they start to go downhill. Your mileage may vary. But it doesn’t seem worthwhile to keep a sorry plant alive for just a couple of cherry tomatoes or a wizened paprika.

So, the first step is getting old plant material out. But wait, you say – didn’t I hear that we should leave plants in the ground until spring for overwintering insects? Sure, but not in the vegetable garden. Here are two good reasons why. First, when you leave perennial plants standing in your landscape so insects can find shelter inside their stems, you commit to waiting until the weather warms in late spring to remove the dead material. That’s going to be too late for vegetable planting in many cases, especially if you rotate crops and are planning to put a spring crop where your summer veggies grew this year. There’s a big difference between a landscape of perennial flowers and an ever-changing garden of annual vegetables.

Secondly, many vegetable plants are great disease hosts. Think about it – if tomatoes and squash didn’t produce delicious food, we’d probably banish them because of how awful they end up looking and how many fungi, bacteria and viruses they spread. The longer that diseased plant material stays in the soil, the more parts drop off and bury themselves, and in some cases that disease lives on until the next year, ready to infect a new host. Ideally you should remove sick plants, or at least the affected parts, as soon as they show disease. This is really hard to do in the middle of the growing and harvesting season, but if you haven’t caught up, at least do it now.

In general, diseased plant material shouldn’t go into home compost. Some fungal diseases will be killed by thorough hot composting, so if you’re rigorous you can take the chance, or else put it on the curb and let your municipal composting do the job. Consult our vegetable diseases pages for information about each type of infection – in some cases, you should just put the plant material in the trash. If you don’t know what infected your plant, it may be best to throw it out. If the plants have been healthy, you can shred and compost them, but remember to not add mature seeds to your compost. We’ve all had pumpkin vines and tomato plants emerge from our pile, and while it’s fun to have volunteers, remember that they may be cross-pollinated and unpredictable in what they’ll produce. Also, don’t add weeds that have gone to seed, or ones that have big roots.

Rake up the surface of your beds; get all that plant debris out. Then, the final step to putting the garden to sleep is covering the soil. If you haven’t planted cover crops, use some kind of organic material to keep the soil from erosion and sprouting weeds. You’ll be surprised how many weeds will cover those beds by spring! Many “winter weeds” have thousands of seeds to spread after they go to flower, so while the bees may appreciate the early snack they provide, you will not. Covering soil also helps to protect the beneficial microorganisms and other critters that inhabit it.

Fall is a great time to add compost to your garden beds, and if the compost is really finished its breaking-down process, it can be used by itself as a mulch. However, it’s probably better to protect it and limit its potential as a weed bed by covering it with other organic materials. Leaves, shredded or un-, are a great option, if you have them around. It’s less important to shred leaves for vegetable garden mulch than for perennial beds; it doesn’t matter that whole leaves mat down and stop young plants from getting through, because you’re going to remove them before planting anyway. Sometimes whole leaves blow away, though, so it’s your choice. Straw is another great option, either from a bale (make sure it’s straw and not hay, to limit the number of grass seeds that will sprout), or in a product often known as “sticky straw” which stays in place better (the “tack” will go away in time and the straw will decay nicely). Don’t make the mistake I did and buy the straw rolls that are held together with netting! Those are meant as a temporary cover for new grass seed. I guess I’ll pull mine up in the spring and maybe I can use the netting to keep the rabbits out of my lettuce bed.

You can also cover beds with a few layers of newspaper and then put leaves or straw on top, if you’re particularly worried about weeds popping up. Whatever lightweight organic material you have will be great, or you can also use black plastic or a roll of weed barrier as a temporary cover if you have nothing else. Plastic keeps the rain away from your soil, however, and it wants the moisture. And when the mosquitoes emerge again, they will breed in the puddles where the plastic isn’t flat.

Finally, fall is a good time to repair fences and fix or add other permanent garden structures. Do it now and you won’t have to do a rush job in the spring.

Then have a nice cup of tea or cocoa and put your feet up!

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

Grow It Eat It 2023

Maryland Grows1 Comment

This is a follow-up to my May article, Grow It Eat It Celebrates 15 Years of Teaching and Promoting Food Gardening! I visited a number of amazing Grow It Eat It (GIEI) projects and activities in 2023 that demonstrate its essential role in helping Maryland residents and communities become more food secure. 

So far in 2023, University of Maryland Extension (UME) Master Gardener Volunteers from 18 counties and Baltimore City worked 7,544 hours on GIEI projects, educating 10,125 residents! Here are some snapshots from the growing season.

Teaching the Public

List of Grow It Eat It classes offered in spring 2023

Master Gardener (MG) Volunteers and field faculty teach lots of classes and workshops each year. Carroll County has a popular series of in-person classes that are taught each spring.

Master Gardener teaching how to test soil texture.

Esther Iglich, UME Master Gardener, Carroll County, teaches students how to perform the “ribbon test” to estimate soil texture.

Teaching Master Gardeners

Master Gardener teaching a class about drip irrigation

Robert Cook, UME Master Gardener, Baltimore City, leads a hands-on drip irrigation continuing education event at the Maryland State Fairgrounds.

Master Gardeners went into the MG Learning Garden to use what they learned to help re-install the drip system.

gardeners on tour of the raised bed garden set up on University of Maryland campus

Meg Smolinski, Coordinator for the UMD Arboretum, leads a Master Gardener tour of the Community Learning Garden in front of the School of Public Health. 

gardeners taking a tour of container gardens

Deb Mayfield, UME Master Gardener, St. Mary’s Co., leads a learning tour of the GIEI container garden at their Fairgrounds.

vegetables growing in containers

The container garden is a popular stop during the county fair, demonstrating low-cost methods, like using repurposed containers for growing food in small spaces.

Community Gardens

people holding up a sign that says Farm Unity at a community garden

UME MGs and field faculty provided technical assistance to the new Farm Unity Community Garden at the Crofton Public Library. This is a communal garden with the harvest distributed to people in need of food. The garden was initiated by Jitendra Rathod (second from left).

three gardeners at an information table for the Prince George's County Community Garden Summit

Esther Mitchell, UME Master Gardener Coordinator, with MG Volunteers Linda Campbell, and Betty Gittings at the Prince George’s County Community Garden Summit. Master Gardeners have helped start five community gardens in the county!

Demonstration Gardens

insect netting placed over a row of kale

GIEI demonstration plots and gardens allow for hands-on learning about new sustainable techniques. MG Volunteers in Montgomery County used “micro-mesh” insect netting to exclude insect pests, making insecticides (synthetic or organic) unnecessary.

potted plants and flowers in a demonstration garden

Visitors and classes also learned how to use drip irrigation with a simple timer to water container plants automatically.

a sign that says Building Your Raised Bed

Signage at the Master Gardener Learning Garden at the State Fair helps new and experienced gardeners make informed decisions. MGs from Baltimore City and 12 counties had 3,617 direct educational contacts during the State Fair.

sweet potato plants growing in a container

2023 is the Year of the Sweet Potato for GIEI. Master Gardener Volunteers demonstrated how to grow sweet potato plants on a trellis and in containers in the MG Learning Garden.

Home, school, and community gardens are essential parts of local food systems. Food gardeners collectively produce enormous amounts of produce, much of which is shared and donated. GIEI projects, classes, and demo gardens teach science-based information and practices, help connect gardeners to resources, and facilitate a shared, respectful learning environment. 

I have no doubt that more great work will be happening in 2024!

By Jon Traunfeld, Extension Specialist, University of Maryland Extension, Home & Garden Information Center. Read more posts by Jon.

Composting and Climate Change

Maryland Grows3 Comments

Composting is probably seen by most people as good for gardens and the environment. After all, compost helps make our soils and plants healthier and keeps green waste from our yards and kitchens out of landfills.

But is composting good in the context of our climate crisis? Doesn’t the composting process generate lots of carbon dioxide (CO2), the principal greenhouse gas (GHG) that traps heat in Earth’s atmosphere? Can composting also mitigate climate change and make our yards and landscapes more climate-resilient? The answer to both questions is YES. This article will show that composting, at the home, community, and municipal/commercial level, is an important global warming mitigation and adaptation tool. As we’ll see, the ways that humans manage this natural process and use the compost can affect the climate benefits.

Composting basics

We don’t make compost! Huge populations of microorganisms do most of the work and we humans manage the process for our benefit. It’s nature’s way of recycling anything that lives and dies, like plants, animals, and microbes.

The decomposition process produces lots of carbon dioxide (CO2), part of the world’s carbon cycling system shown in this graphic:

illustration of the carbon cycle - plants use carbon dioxide from the air and water from the soil to build carbohydrates
Plants exude carbohydrates through their roots to feed soil organisms. Those organisms release carbon dioxide through respiration. Illustration by Jocelyn Lavallee, Ph.D., Soil Scientist

This CO2 release is considered biogenic (happens through natural biological systems), not anthropogenic (people-made), and is not included in the calculations of greenhouse gas (GHG) emissions that drive global warming and climate change.

The three primary GHGs are:

  • Carbon dioxide (CO2) — 300-1,000 year atmospheric lifetime; 86% of total GHG emissions
  • Methane (CH4) — 84X the global warming potential of CO2; 12 year atmospheric lifetime; 7% of total GHG emissions
  • Nitrous oxide (NO2) — 265X the global warming potential of CO2; 100 year atmospheric lifetime; 6% of total GHG emissions

There are many factors that determine the potential for composting to generate methane and nitrous oxide, like the mix of materials being composted, temperature, moisture, pile size and configuration, and aeration. Compost piles and windrows that are waterlogged and low in oxygen (anaerobic) are more likely to generate these GHGs. Composting is “climate-friendly” when it’s done in the presence of air (aerobic). Home and community composters turn piles by hand to keep them aerated and large-scale composting facilities use mechanical turners and force air into windrows with blowers. Well-managed composting at any scale releases very little methane or nitrous oxide into the atmosphere. 

Direct climate benefits of composting

  • Dumping food wastes and grass clippings in landfills generates large amounts of methane because the decomposition process is anaerobic. Landfills release about 17% of total U.S. anthropogenic methane emissions and food waste makes up 24% of landfill space. Burning organic wastes releases GHGs and toxins. Composting these organic wastes using best practices greatly reduces emissions.
  • Carbon sequestration: Compost continues to degrade after soil incorporation. Some of the carbon cycles through soil microorganisms and some is held tightly to clay particles, protected against decomposition, and becomes part of the long-term reserve of stored carbon.

Indirect climate benefits of composting

The mid-Atlantic climate is becoming wetter and warmer overall, punctuated by localized extreme weather events, like record-breaking rainfall and extreme drought and heat. Intense storms can cause soils and nutrients to wash away and warmer temperatures cause more rapid organic matter decomposition and turnover, especially if soils are tilled and uncovered.

Adding compost to soils makes them more resilient by:

  • Holding more water in the soil during periods of drought and extreme heat
  • Reducing erosion (washing away of soil during extreme rainfall) and nutrient run-off) due to improved soil structure (larger, more stable aggregates or crumbs)
  • Improving plant growth, by slow release of plant-available nutrients
  • Reducing the need for synthetic nitrogen fertilizers which require natural gas for their production
  • Reducing the need for potassium and phosphorous fertilizers (derived from mined mineral deposits that are dwindling worldwide)
  • Binding and degrading toxic metals and pollutants
  • Substituting compost for peat products can help reduce the release of CO2 from commercial peat extraction from wetlands 
illustration of how compost combats climate change - increases water holding capacity - sequesters carbon in soil
Poster by the Institute for Local Self-Reliance

Home composting

Managing and recycling as much yard waste as possible on-site is often the most climate-friendly approach because it reduces GHG emissions from transporting and processing or landfilling organic waste. You can do this by recycling grass clipping (“mow ‘em high and let ‘em lie”), mulch-mowing tree leaves and leaving them in place, or using them as mulch, composting yard and garden waste, and burying kitchen scraps. These practices help to recycle nutrients on-site and increase soil organic matter. Selecting or building a non-plastic composter can also help reduce GHG emissions.

Municipal/commercial composting

This is the next best option for organic wastes that cannot be managed on-site. Commercial and municipal composting operations do create GHG emissions from the trucks and equipment, powered by fossil fuels, that are used to collect, transport, and process organic waste and compost. The closer the source of organic waste to the facility the lower the emissions and the greater the benefits. On balance, composting on a large scale can also help mitigate climate change.

illustration showing that the carbon sequestration benefits of municipal composting outweigh the greenhouse gases generated by transportation, storage, and processing compost

To summarize: aerobic composting reduces GHG emissions compared to the landfilling and incineration of organic wastes. The resulting compost sequesters carbon when mixed into soils and improves soil health and resiliency. Composting at home and in your community is the most climate-friendly approach but commercial and municipal composting is another important tool that helps mitigate climate change.

References

By Jon Traunfeld, Extension Specialist, University of Maryland Extension, Home & Garden Information Center. Read more posts by Jon.

Pepper Report

Maryland Grows3 Comments

Just a quick note from me (Erica) this month to report on some new pepper cultivars I’m growing. These include ‘Lesya’ sweet pepper, ‘Tam’ jalapeño, and ‘Escamillo’ frying pepper.

First, ‘Lesya.’ Wow, I’m in love with this one.

It’s a heart-shaped red pepper, about 3-4 inches long, thick-walled and super-sweet. Those thick walls make it great for roasting, but it can also be eaten raw or cooked other ways. It also just looks terrific growing on strong plants that don’t get leggy and seem pretty disease-resistant.

I bought seed for ‘Tam’ jalapeño because it’s supposed to be on the milder side, but with some spice to it, unlike the ‘Nadapeño’ heatless type I grew last year (which was kind of boring). The first thing I did with the fruits was to make them into refrigerator pickles (sliced), and those turned out pretty hot. So I thought I’d do a taste test comparing ‘Tam’ to other jalapeños. Please note, this was not a scientifically valid comparison; that would involve a lot more testers (instead of just me and my son), a lot more peppers, and many tests over time. Peppers can be more or less hot depending on the weather, the soil the plants are grown in, the genetics of particular plants, and probably lots of other factors.

Anyway, I picked a couple of peppers from the Derwood Demo Garden, and a ‘Tam’ from my own garden.

L to R: ‘Tam,’ ‘Lemon Spice,’ and ‘Jalafuego’ jalapeños

I’ll also note that picking the ‘Lemon Spice’ fully ripe made the comparison even less valid (but it’s so pretty!), and that I should have found a larger and more mature ‘Jalafuego.’ But onwards. Of the three, ‘Lemon Spice’ was definitely the hottest, nice and eye-watering. ‘Tam’ had practically no heat on first bite, and then it crept up on me, but it was definitely milder. ‘Jalafuego’ was weirdly mild as well; I suspect another fruit on another day would have knocked my socks off. So, nothing definitive, but I think if you want a milder jalapeño ‘Tam’ is worth trying.

Apparently this year some people, in some places, bought ‘Tam’ plants that turned out to be sweet banana peppers – all part of the great pepper seed mixup that you can read about on this Garden Professors blog post – but my seed (purchased from Sow True Seed, for the record) turned out to be the real thing.

Finally, this is my second year growing ‘Escamillo’ frying pepper, and I’m very satisfied.

It’s a nice meaty yellow pepper that can easily reach 6 inches or more, ripens up fast, has thick walls for good roasting, and is also great for frying or eating raw.

And that’s the pepper report!

By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.

Vinegar Acidity for Home Canning: Preserve Your Garden Produce Safely

Maryland GrowsLeave a comment

The National Center for Home Food Preservation, which is out of the University of Georgia Extension, has been fielding questions about using 4% acidity white distilled vinegar that is available for home cooks on grocery store shelves. People will often use 4% acidic vinegar to help make salad dressings and sauces. However, it is recommended for safety when canning to use 5% acidic white distilled and cider kinds of vinegar. We ask home canners to read the label of the vinegar they intend to buy at the store closely to look for the acid percentage before purchasing and using it for canning purposes.

Vinegar-acidity-level-for-home-canning-1Download

Further questions? Email Shauna C. Henley, PhD at shenley@umd.edu.

Shauna is the Family & Consumer Sciences Senior Agent at the University of Maryland Extension, Baltimore County

Insects: Our Most Under-Appreciated Neighbors

Maryland Grows3 Comments

Why should I want bugs, insects, and creepy crawlies in my yard or green space?

Insects are an incredibly diverse group of organisms, with 91,000 described species in the United States and likely an equal number yet to be described by scientists. Only an exceedingly small fraction of these species ever have negative impacts on humans as “pests” (<1% of species). Often the overabundance of pest species is due to human agricultural and landscape practice choices. The vast majority of insects in shared spaces with humans like yards and parks are going about their own lives. In addition to being fascinating creatures deserving of habitat in their own right, they also often contribute to unnoticed but very important tasks that help humans, termed “ecosystem services.” The next time you see one of these critters in your yard, consider thanking them rather than smashing them.

What are ecosystem services?

Ecosystem services are benefits that humans gain from the environment. Examples of ecosystem services include water filtration, raw material production, erosion control, and pollination. Some ecosystem services, like the maintenance of atmospheric gasses (e.g. plants remove carbon dioxide and produce oxygen that humans breathe), are noticeable and directly impact our everyday lives. On the other hand, services like decomposition may go unnoticed because they indirectly affect us.  

Insects (and their arthropod relatives like spiders and earthworms) play vital roles in many ecosystem services. This is often due to insects interacting with plants in some way, though insects also provide food for many other animals. Below are some examples of the ecosystem services that insects contribute to.

Water filtration

Filter-feeding insects positively affect water quality because they remove particles of dead organic material. Insects retain many of the nutrients they filter out of the water, thus reducing the likelihood of algal blooms, their associated toxins, and dissolved oxygen “dead zones.” This is crucial because clean water provides habitat for other plants and animals like fish and amphibians. It also means less effort is required to purify water for human use. 

Types of insects that improve water quality:

  • Blackflies, mayflies, stoneflies, and caddisflies (Note: the underlined insect groups are not “true” flies in the taxonomic Order Diptera; they are part of other orders.) 

Other types of organisms that improve water quality:

  • Mussels, crayfish, snails

More information: Why Care About Aquatic Insects

an illustration of the diversity of insects in an aquatic environment
Source: https://www.nsf.gov/news/mmg/mmg_disp.jsp?med_id=66886&from=Many types of insects live in or near water. Caddisfly larvae, pictured bottom center, filter debris out of the water as they feed. Credit: National Science Foundation

Biocontrol

Biocontrol is when natural enemies are used to suppress pests and reduce the amount of damage they cause. Natural enemies are insects that are antagonistic to pest insects. There are three types of natural enemies: predators, parasitoids, and pathogens. Preserving natural enemy populations is crucial to reducing our reliance on pesticides because when natural enemies are active, pest outbreaks are less likely to occur in the first place. Predators need food all year, so they also need alternate prey available in order to prevent pest outbreaks. Pesticides eliminate beneficial insects in addition to pests, so they should be used only as a last resort.

Fun fact: Fireflies spend much of the year as larval predators belowground, feeding on pests like grubs in turfgrass yards. If no prey is available in yards, then there will be no display of adult fireflies in the summer.

Types of insects used for biocontrol:

Other types of organisms used for biocontrol:

  • Fungi, birds, amphibians, reptiles, and mammals

More information: Approaches to the Biological Control of Insect Pests.

small wasp parasitizes eggs of a pest insect
An adult samurai wasp lays eggs in a mass of brown marmorated stink bug eggs. Credit: Chris Hedstrom, CC BY-SA 2.0 DEED

Seed dispersal

Seed dispersal is when seeds are moved away from the parent plant. Seeds are moved when insects knock them off while feeding or when insects collect and then move seeds to a new location. Seed dispersal is important because it reduces resource competition between the parent plant and offspring plants. It also makes germination and seedling survival more likely, especially in arid climates. 

Types of insect seed dispersers:

  • Ants (most effective), beetles, wasps, thrips, and some moths

Other types of seed dispersers:

  • Fruit-eating animals (frugivores), such as some monkeys, lizards, and bats
  • Unwitting animal dispersers of sticky seeds like this

More information:

Seed Dispersal – The Australian Museum

The Conservation Physiology of Seed Dispersal

two ants carrying a seed
Two ants carrying a plant seed. Credit: Mark Chinnick, CC BY-NC-ND 2.0 DEED

Decomposition & nutrient cycling

Nutrient cycling and decomposition are two important processes that rely on one another. Nutrient cycling is when soil nutrients are taken up by plants, insects eat plants, and then those nutrients are reintroduced into the soil when dead insects and droppings are broken back down into nutrients via decomposition. Decomposer insects help clear dead animals and plants off the ground which would otherwise accumulate everywhere. They also help create soil texture and circulate nutrients back into the soil, which plant populations and productivity depend on.

Types of insect decomposers:

  • Many beetles, springtails, termites, wood cockroaches, and some fly larvae (maggots)

Other types of decomposers:

More information: Decomposers

a black shiny beetle on a log
An adult bess beetle crawls across a log. Bess beetles are important decomposers and return nutrients to the soil. Credit: Kelsey McGurrin, used with permission

Supporting food webs

Insects are a main source of protein and nutrition for many animals (and even some plants). They play a crucial role in transferring energy from plants to larger animals that eat insects like spiders, birds, frogs, fish, bats, foxes, opossums, and bears. This wide food base that they provide allows for functioning, stable ecosystems that are resilient to disruptions.

Fun fact: By weight, there are roughly 300 times more insects than humans on Earth.
There are so many animals that eat insects, but here are just a few examples:

  • Terrestrial bird species, in particular, feed their babies almost exclusively with insects, and if there are fewer insects, baby birds are less successful at fledging from nests.
  • Popular fish like salmon, bass, and trout eat insects, especially when they’re young.
  • Grizzly bears will eat tens of thousands of moths a day to prepare for hibernation.
two mockingbirds eating a praying matis
Northern Mockingbird adult feeding a praying mantis to a young bird. Credit: Becky Matsubara, CC BY 4.0 DEED

Pollination

Pollination is the transfer of pollen between flowers, resulting in flower fertilization and seed/fruit production. It is an unintentional consequence of pollinators going from flower to flower to feed themselves. Pollination is crucial for human survival, as 80% of plant-based foods and products rely on animal pollination. According to the USDA, pollinated crops are worth $18 billion in the US alone. Foods requiring pollination include apples, blueberries, chocolate, coffee, grapefruit, peaches, peppermint, sugarcane, tequila, and vanilla. 

Fun fact: beetles were likely the first insect pollinators– starting 200 million years ago!
Types of insect pollinators:

  • Bees, wasps, beetles, flies, ants, butterflies, and moths

Other types of pollinators:

  • Birds and bats

More information:

Pollination Basics

What is Pollination?

Why is Pollination Important?

Pollinated Foods

Blueberry Digger Bee pollinating blueberry flowers. Credit: Judy Gallagher, CC BY 2.0 DEED

By Yasmine Helbling, Kelsey McGurrin, and Karin Twardosz Burghardt, from the University of Maryland Department of Entomology, Burghardt Lab