You won’t find a lot of experienced gardeners—at least those who are honest with themselves—talking about “rules” in gardening. That’s because, strictly speaking, there are very few of them. There are certainly guidelines, which are created through a combination of experimentation, synthesis of results, lots of mistakes and corrections, and effective communication of principles. There’s also a lot of bad advice out there, which you can weed out in simple ways (try using “Extension” as part of your web searches) or by disregarding those helpful nuggets that use only anecdote or tradition as rationales. (“This happened to me once, so it must always be true!” “My grandmother always said…”) Personally, I think you can also ignore pundits who declare rules without exceptions. There are always exceptions.
Or maybe I’m saying that because I just broke a rule. It’s May, so time for hardening off seedlings. The guideline for hardening off is to introduce your young plants to the outdoors gradually. Carry your tray full of pots outside and put them in a sheltered spot (out of the wind and sun). Give them a few hours of outdoor conditions and then bring them inside again. Next day, lengthen the time outdoors. Over a week, expose the plants to more sun and some light breezes. Leave them outside overnight on the last few nights before you plant them in the garden. This way, they don’t get shocked by a sudden change in exposure, and they will settle into their new life more readily. Failure to make this gradual transition could result in a serious growth setback, or even in death. (Of the plant. You’ll be fine, I hope.)
Peas growing at the Derwood Demo Garden in 2015 in a very appropriate container! (We must have cut out the bottom, since you need a soil depth of more like 8-10 inches to grow peas.)
Spring is the time to plant peas! We are nearing the end of our pea-planting window, so if you want to grow them this year, get them in the ground soon. Sowing peas is very weather- and temperature-dependent. There’s a tradition of planting them on St. Patrick’s Day, which is not a bad guide, but obviously if there’s snow on the ground that day, or it’s pouring rain or freezing cold, you might want to hold off. Peas are very hardy, and since we’ve had a recent trend of warm late winters (followed by chilly springs), planting them as early as February might actually work, but be ready to throw a protective row cover over the plants when there’s a freeze. But early April is not too late, since it’s often on the cool side well into May. If the weather gets too warm, peas will not bear well, and the vines will dry up.
Soil temperature is also important. Peas can germinate at as low as 40°F, but warmer temperatures (up to 75°F) will aid germination. If the soil is both cold and muddy, pea seeds will likely rot before germinating. Peas grow easily in containers and raised beds, and using these will provide more drainage.
You can also pre-germinate pea seed (see instruction on the HGIC “Growing Peas” page). This pretty much guarantees that pea seeds will at least start growing, and once they get going they’ll likely mature. If you don’t have time for pre-germination, just soaking the seeds for a few hours in a container of water immediately before planting will help them get a good start.
Pea seeds soaking in water prior to planting
Pay attention to the “days to maturity” listed on the seed packet. You can find varieties of peas that mature in as little as 30 days, or as long as 80 days, but most of them will be in the 50-70 day range. Giving them a good head start with the techniques above will help you harvest a crop in time. Shelling peas, snap peas and snow peas can all be grown easily here in Maryland. Pick your favorite! You can also find types that emphasize the growth of tendrils, used most frequently in Asian cooking.
Peas should be planted thickly, 1 to 3 inches apart. The growing plants will tangle together and can support each other, but they’re helped out by using a trellis or fence to climb on. You can also create a trellis out of sticks—just take some small fallen branches and shove them into the ground, overlapping to make a rough structure. Be creative! Place your trellis when you plant your peas, not after they have sprouted, to prevent damage to roots. Read the variety description to find out how long the vines will grow; there are dwarf varieties that top out at less than two feet or long vines that can reach six feet.
Some notes on nomenclature:
The edible peas you grow in your garden are Pisum sativum. They are often called “sweet peas” because they are sweeter than field peas (see below).
“Sweet peas” are also a flowering vining plant you may grow as an ornamental, Lathyrus odoratus. Don’t confuse the two when you’re buying seeds! Sweet pea is a lovely plant but not edible, and the seeds may be toxic.
“Field pea” can refer to Lathyrus hirsutus, also known as Austrian winter pea, which you can buy as cover crop seed. Also not recommended as an edible crop.
“Field pea” can also refer to the plant known as cowpea, Southern pea, or black-eyed pea (though only some varieties are white with black spots). The scientific name for these is Vigna unguiculata subspecies unguiculata. (Subspecies sesquipedalis is known as yardlong bean or asparagus bean.) Cowpeas are grown more like beans than peas, in summer weather, and they are a great edible crop as well as a forage crop or cover crop.
So the moral of this is, as usual in gardening: know what you’re buying, and pay attention to scientific names. Also, if you want pretty flowers, Pisum sativum is not bad.
Flower colors vary, but purple is especially nice!
By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.
In today’s post, I am going to focus on how to embrace low-till gardening systems, but first a quick refresher on soil.
The importance of soil
Soil is a living and complex natural covering of the Earth.
Soil acts as a sponge to absorb water, nutrients, pollutants, and carbon.
Many aspects of soil cannot be changed, but properties can be managed to provide the elements needed to grow desired plants and it is the pillar of plant life in your landscape/ecosystem.
Chemical, physical, and biological components make up the living soil.
Soil scientists are only beginning to understand the complex biological systems and how important they are to overall soil health.
Topsoil is the usable portion for gardeners. Thus, all management techniques should aim to protect and enhance this valuable layer.
What you might see in a traditional in-ground garden with soil tilled in between the rows of desired plants. Image by Nadezhda56 from Pixabay
Pros and cons of tilling garden soil
In-ground gardening techniques have long been the method of vegetable gardening used in large-scale production. This system focuses on the mechanical tilling of a section of the earth. This soil is prepared and then seeds or transplants are placed in rows. In between these rows of plants is the walkway, which is either tilled at regular intervals or mulched to prevent weeds from growing. This technique works well but results in high levels of soil disturbance. Mechanical tillers require the use of a motor or a large amount of physical labor/exertion if done by hand. Once the soil is tilled, it is more likely to suffer from soil compaction.
100% no-till gardening options
For alternative gardening methods that are 100% no-till, learn more by visiting these links:
Although tilling is the easiest and fastest way to create new planting areas and is also used as a weed control option, mechanical tilling of the soil (especially multiple times throughout the season) breaks down its structure and can reduce soil quality.
Negative effects of repeated mechanical tillage
Repeated tillage:
Breaks down organic matter. The more often you are churning the soil the more the natural structure can be degraded and compacted. It disturbs natural pathways for water flow and for soil macro- and microorganisms.
Reduces soil stability by breaking apart aggregates.
Exposes rocks and deeper layers of soil that are less developed.
Exposes the seed bank of the soil to light and allows new weed seeds to germinate.
Differences between conventional and low-till systems
Low-till gardening systems often look different than traditional gardening systems. Low-till management techniques focus more on installing permanent pathways that are not disturbed yearly. These pathways may be outlined with stones or other permanent items. In the actual planting bed, low tilling is done with a handheld tool to create the planting space. Often these tilled areas would be smaller in size.
Implement these practices slowly and expand as you have success.
Use a broadfork to loosen the topsoil, but do not dig deeper than necessary. This allows the natural pathways made by micro- and macroorganisms (earthworm tunnels) and plant roots to stay intact.
Keep the soil covered. Use mulch to prevent erosion. Mulch sourced from your landscape such as pine needles, grass clippings, clean straw, newspaper, cardboard, etc. can be used.
Mother Nature always wants the soil to be covered. If you disturb the soil and do not cover it with mulch or other weed barrier, plants, or seeds, then weeds will grow. Wind and rain can quickly dissipate topsoil— replacing one inch of natural topsoil can take 500-1000 years! If the soil is covered it should not be as easy to wash or blow away.
Add organic matter– whatever you have readily available. Mushroom compost, bagged cow manure, homemade compost, leaves, grass clippings, kitchen waste, etc.
Plant crops (cover crops, green manure) that will be cut down and left to decompose naturally in the soil or lightly turned in with a broadfork.
Malabar spinach growing with corn. Example of companion planting in a no-till garden. Image by MAURÍCIO UCHÔA Bruttos from Pixabay
More on low-till gardens
Low-till is part of some permaculture practices. Permaculture practices have a goal of creating “permanent” growing spaces that utilize natural self-sustaining systems. Some of these permaculture practices can be adapted and used in our landscapes, especially those that include native plant areas, perennial fruits, and herbs. Other terms that incorporate these ideas and principles are food forests or forest gardening.
Tillage is a good tool, just remember to use it at the right time and for the right purpose to capture the benefits. Good soil management practices may be open to interpretation based on your personal goals for your garden space and remember that what makes sense in your landscape doesn’t always have to match what others are doing. If you are seeing positive results, then keep trying new techniques.
I hope that this Spring finds you dreaming and excited about the upcoming growing season and making a positive impact in adding diversity to your landscape.
2024 is Grow It Eat It’s Year of Heirloom Tomatoes! We’re going to have lots of resources available soon to help you celebrate these delicious and historic vegetables (botanically fruits), and we hope you’ll participate by planting a few in your garden. I thought, as an enthusiastic heirloom tomato gardener myself, I’d take a moment to make some introductions.
First of all, what is an heirloom tomato? Well, I think we know what a tomato is; what puts it in the same category as Grandma’s topaz necklace or Grandpa’s grandfather clock? They’re all handed down through the generations. “Heirloom” doesn’t have any single definition when it comes to vegetables. It can mean that the origin of a particular variety goes back more than 100 years, or 75 years, or that it was first grown before a certain date. Many people use World War II as a marker, because the growth of hybrid crops boomed in the subsequent decades, and a lot of older varieties disappeared from seed catalogs. Varieties grown in a particular community or culture, or through several generations in a particular family, are also considered heirlooms. Family names are often part of a variety name, which makes you feel like a cousin when you grow them!
It’s February, so really time to think about starting plants from seed, if not necessarily time to actually start them. (If you are itching to get going, I wrote a post a while back about which seeds to sow in February. Hint: not tomatoes.) Let’s continue with the guide, which I hope you’re finding a practical help to this complicated subject. (Parts One and Two also available.)
Choosing Seeds
If you have not already impulsively ordered a bunch of seeds without concern for whether they’re the easiest ones to grow (in which case you are a person after my own heart), now is a good time to go shopping. In most cases these days that means shopping online. You can certainly buy seeds at garden centers and even supermarkets, though they may not be on display this early, but you get a much better selection by visiting the full catalog of a seed company website.
I’ve written a post about choosing a seed catalog to order from, so won’t repeat that information here. If you are confused by the jargon used in seed catalogs, Jon Traunfeld explains it in this post.
But which plants are best for novice seed-starters to grow from seed? First of all, you shouldn’t always let ease dictate what you choose to grow. If you like a vegetable (or a flower) and want to grow it, you may be willing to take on the challenges involved. Some seeds are more cooperative than others, however. Of the many veggies that are best started indoors, here are a few I recommend for beginners:
Let’s talk more about seed-starting! Last month I posted about how to get your house ready for a seed-starting project: picking a space to use, deciding where to hang your lights, and choosing the lights. I also wrote a bit about what containers to use, but in this post I’ll give you more detail, and also talk about what “soil” (actually soilless mix or growing medium) to use.
Seedlings growing in recycled plastic egg cartons
Containers
There are basically two parts to a seed-starting apparatus: the tray, and the pot or cell. Here’s some information about each.
Trays
The purpose of a tray is to contain or capture water. You need a tray unless you want a big mess. It should not have holes in it.
Trays can be any size larger than a pot. Standard industry size is 10”x20”. You can also use takeout containers (or any food-grade plastic), old baking pans, or anything else that suits your needs.
Most trays are plastic (aside from the baking pans). Standard trays full of pots sometimes crack when lugged around and left outside, so consider doubling them up or buying the heavy-duty ones.
Pots
The purpose of a pot is to contain the medium in which a plant grows. Pots are separate entities, and cells are connected pots. You can buy cell sets that fit standard trays. You can also save the cells and pots that you bought plants in. Yogurt cups and the like are great to recycle into pots, or you can use plastic drinking cups. Plastic egg cartons can substitute for the smallest size of cell set.
Pots must have drainage. If water can’t drain out of a pot, plant roots can rot. Commercial pots will have holes already; if you use recycled items, punch holes with a nail or a knife or whatever you have (the shape doesn’t matter, but make several).
If you don’t want to buy plastic, you can spend more and get pots or cell sets made of silicone or ceramic. These should last many, many years and be easy to clean.
Any pot of the above types needs to be cleaned before each use. A 10% bleach solution is effective at killing pathogens that may lurk in bits of leftover soil. You can instead use dish soap if you’re pretty sure the pots haven’t been exposed to plant diseases.
The other type of pot/cell set on the market is the plantable kind. These are made of compressed peat, coir, or processed manure (they don’t smell!). They are filled with growing medium just like a plastic pot, but the whole thing can be put in the ground when the plant is ready.
Make very sure to keep plantable pots moist at all times, starting by soaking them before using and continuing until planting time. Remove any dry rims and some of the bottom before planting. Dryness can prevent proper plant growth.
Plantable pellets (made of peat or coir) expand when moistened and have a hole to put a seed into. They can also be planted whole, or transplanted into a bigger pot.
How big a pot to choose? It depends on how many times you want to “up-pot” or transplant into a larger container. If you start with small cells, the seedlings will have to be moved into larger pots, maybe more than once, but you are saving space, soil, and water in the early stages. (Just be sure you have room under lights for your expanded plant kingdom!) Planting directly into larger pots means you won’t have to up-pot, but you may waste time, space and materials if seeds don’t germinate, and it’s harder to keep the soil watered.
Plastic cell tray (black), silicone cell set (orange), peat pots (small), pots made of cow manure (large), compressed coir pot (single)
Growing Medium
It’s recommended to start seeds in a soilless mix consisting mostly of peat or some other organic material. There are lots of choices available on the market, and if you’re ambitious, you can mix your own. Read HGIC’s page on the topic and check out Jon Traunfeld’s post on peat-free mixes.
For smaller seeds, you want to find a finer-cut mix (lightweight and fluffy, not heavy like sand); larger seeds can tolerate a mix with larger particles. The name on the package may not mean much: “seed-starting mixes” can be quite rough in texture, and “potting mixes” vary a lot too. Look at the ingredients and try to avoid anything with “forest products,” which seems to mean little bits of wood.
Seeds themselves contain nutrients to get a baby plant started, so germination and early growth don’t require fertilizer in the growing medium. If you’re going to be growing the plant in that medium for more than a week or so, though, the mix should have fertilizer or compost in it. Alternatively, you can add fertilizer when you water. Or you can add your own compost to your growing mix, as long as it’s finished and screened, but don’t use garden soil, which may contain pathogens or weed seeds.
Next month I’ll take you through choosing what seeds to start, how to get them to germinate, and how to care for your young seedlings.
In the meanwhile, here are some more items you might consider acquiring into addition to the seeds themselves:
A seedling heat mat, especially if you are planning to start seeds for summer vegetables and flowers. Seeds need warmth to germinate, and sometimes a bit of extra heat helps.
A sprayer (for getting the soil surface wet without washing tiny seeds away) and a watering can with a narrow spout.
Clear plastic domes that fit over your trays. These help keep moisture in when seeds are germinating and plants getting started. You can buy them or improvise them out of recycled plastic clamshells (like for salad mixes).
Labels!!!
I’ll tell you more about all these helpful items next month.
By Erica Smith, Montgomery County Master Gardener. Read more posts by Erica.
Do you ever wonder where insects go during the winter? This year, as you snuggle up under a warm blanket to escape the winter cold, think about how you can help the beneficial insects in your garden do the same. The harsh conditions of the cold season can be challenging to deal with, but some insects can benefit from habitats that provide them with shelter not only during the winter but all year round. Ground beetles are a great example of insects that can be a tremendous help in the garden, but also appreciate a good nook or cranny to hide out in while the weather is less than ideal.
Ground beetles are one of the most diverse insect families in the world and can be found in many shapes and sizes across Maryland’s gardens, farms, and natural areas. Like butterflies and moths, ground beetles go through a complete metamorphosis, changing drastically in appearance throughout their life cycle. They begin their lives as larvae that resemble small, fast-moving, armor-plated caterpillars with giant mandibles – a little intimidating, but luckily, they’re on your side! Ground beetle larvae mostly feed on other small invertebrates, including a range of garden pests like aphids, grubs, and caterpillars. Ground beetles generally spend a few months as a larva and can live several more years as an adult.
Ground beetle larva with a potential snack. Photo: Benjamin Burgunder (CC-BY)
Adult ground beetles can be anywhere from ⅛ to 1 ½ inches long and oval-shaped with a plain dark coloration, but some may sport a green or bronze iridescence. They have long legs and thread-like antennae. Like other beetles, they have hard wing covers, usually with prominent ridges running across their length. These wing covers protect hind wings that may sometimes be used to fly, but many species have lost this ability. Even those that retain it are more likely to be found running across the ground or burrowing down just underneath the substrate.
Ground beetles have large, powerful mandibles that they use to capture and chew their food, which they’re not picky about. They are well-known for eating a wide variety of foods, but many species have a preference for one type over another. Some species, including Chlaenius aestivus, Scarites subterraneus, and Poecilus chalcites are famous predators of other invertebrates including aphids, caterpillars, and slugs, and can help keep pests at bay in your garden. Other species such as Amara aenea, Harpalus pensylvanicus, and Anisodactylus sanctaecrucis also feed on other invertebrates, but have additionally been studied for their useful tendency to eat the seeds of common weeds, helping to manage these weeds before they even start growing.
Some common ground beetle species in Maryland include insect pest predators Chlaenius aestivus (top left) and Scarites subterraneus (top right), as well as weed seed eaters Amara aenea (bottom left) and Harpalus pensylvanicus (bottom right). Photos: Zachary Dankowicz, Debbie Johnson, Martin Galli, Don Marsille (CC BY-NC)
While ground beetles do not damage garden plants, they may be considered a household pest if found wandering through homes. Most ground beetles are nocturnal and attracted to lights, so they may inadvertently enter houses and have trouble getting out. In this case, simply use a cup and a piece of paper or your hands to capture them. They do not pose any significant danger to you or your pets, but if handled roughly, their mandibles may deliver a small pinch. Relocate them outside where they can continue to serve you and your garden.
If you want to help support these useful critters, there are several actions you can take.
Avoid practices that disturb soil fauna such as frequent tillage, and don’t use broad-spectrum insecticides, i.e. those that harm a wide range of insects including beneficials.
Don’t leave the ground bare. Bare earth does not provide the best protection against the cold, so cutting back your plants before or during the winter to tidy up your garden actually may be harmful to resident ground beetles. Applying a straw mulch can help cover up bare earth and provide shelter for these overwintering insects. Planting perennials in or near your garden can also provide a lasting habitat for beneficial insects. Establishing stretches of perennial grasses called “beetle banks” is a common technique used to increase ground beetle numbers on farms in many places around the world.
Create sheltered spaces. Ground beetles will even hide out underneath large stones, logs, or brush piles. In addition to helping ground beetles, creating sheltered habitats and leaving ground cover over the soil can also help other beneficial insects, including pollinators and insects that are important food for birds (“leave the leaves!”).
Because they can live for several years, helping ground beetles for one year can result in much greater numbers during the following years as well. It’s an investment in your garden’s natural defenses against pests! Having these predators around can help keep you from needing to resort to using pesticides which may be harmful to your health and to the environment. Next time you’re making plans for your garden, consider helping out your garden’s natural protectors and enjoy as they return the favor.
References
Dennis, P., Thomas, M. B., & Sotherton, N. W. (1994). Structural Features of Field Boundaries Which Influence the Overwintering Densities of Beneficial Arthropod Predators. The Journal of Applied Ecology, 31(2), 361. https://doi.org/10.2307/2404550
Jordan, S. F., Hopwood, J., & Morris, S. (2020). Nesting & Overwintering Habitat for Pollinators & Other Beneficial Insects. The Xerces Society for Invertebrate Conservation.
MacLeod, A., Wratten, S. D., Sotherton, N. W., & Thomas, M. B. (2004). “Beetle banks” as refuges for beneficial arthropods in farmland: Long-term changes in predator communities and habitat. Agricultural and Forest Entomology, 6(2), 147–154. https://doi.org/10.1111/j.1461-9563.2004.00215.x
Philpott, S. M., Albuquerque, S., Bichier, P., Cohen, H., Egerer, M. H., Kirk, C., & Will, K. W. (2019). Local and Landscape Drivers of Carabid Activity, Species Richness, and Traits in Urban Gardens in Coastal California. Insects, 10(4), Article 4. https://doi.org/10.3390/insects10040112
Philpott, S. M., & Bichier, P. (2017). Local and landscape drivers of predation services in urban gardens. Ecological Applications, 27(3), 966–976. https://doi.org/10.1002/eap.1500
By Alireza Shokoohi, M.S. Student, Department of Entomology, University of Maryland, College Park.
