Soil – Page 3 – Maryland Grows

Planning and budgeting for a new raised bed garden

February 24, 2021October 26, 2022Maryland Grows14 Comments

Even though it is snowing again today, I am dreaming of gardening season and I am working on a budget for a new raised bed garden that will be 8’ x 4’ x 12”. I have always grown vegetables in a traditional in-ground garden, which only requires some tools for preparing the soil, soil amendments, and a suitable location (full sun with good soil). However, I want the advantages of a raised bed:

earlier soil warming;
more focused usage of growing space (through succession planting and square foot gardening techniques);
less body bending to plant, maintain, and harvest; and
getting to plant cole crops sooner (with my in-ground garden, I have to wait until late May for the ground to be unfrozen and dry enough to run the the tractor tiller).

garden with a fence — Raised bed made from grapevines and a plastic liner.

A lot of inspiration can be found on the internet for building materials, but think about materials that you may already have on hand or something you can find freely or cheaply. More information on raised beds can be found on the University of Maryland Extension website.

Some things to keep in mind:

Natural materials (stones, logs, untreated lumber, cement blocks, sawmill slabs, bricks, etc.) are safe, affordable, and often can be scavenged/repurposed if you aren’t afraid to ask or do some physical labor.
What is your skill set? Maybe you can work out a trade with someone who can help you build the raised bed.
Any time you can buy items in bulk, you will save money.

After doing some research, I plan to purchase new pine lumber from a local box store (easy to find and within my budget). Pine or softwood lumber should last anywhere from 3-5 years. Using commonly available sizes/dimensions, I will be spending approximately $80 (if it lasts 3 years, that’s $27 a year). Cedar boards would cost double the money but they could last closer to 15 years (cedar was out of stock in a lot of locations I checked).

Most stores that sell lumber will cut the lumber for no extra fee. It is sometimes cheaper to buy a longer board and have it cut into smaller pieces for transport. Be sure to plan ahead.

The most expensive part of creating this garden will be the topsoil, since I don’t have any extra in my landscape to use. The soil is an investment and will be a resource that I can use for many years to come to produce nutritious fruits and vegetables.

I used a free cubic feet calculator to figure out an estimate of how much soil I will have to purchase for my 8’ x 4’ x 12” garden. See the calculations below.

Soil is expensive and hard to transport and handle. I am prepared to do this step over the course of several days or have some people help me. Bagged topsoil usually isn’t the best quality and can add a lot of expense, but the source can be traced if any issue should arise, and also gives anyone with access to any vehicle type/transportation the ability to create a garden. Bulk topsoil and compost is usually sold by the ton or cubic yard, so the free calculators are helpful for figuring out amounts needed. Soil testing is recommended for raised bed gardens.

Soil Type	Price
Bagged Topsoil (43 bags of 0.75 cu foot)	$110
2/3 bagged topsoil, 1/3 bagged compost (45 bags)	$145
Bulk topsoil/compost	$65

The bottom line is that the raised bed could cost up to $225 depending on which option I use for soil. Using bagged soil/compost mixed ($145 + $80 lumber) is going to cost the most $225. If I use the bulk topsoil/compost option and use my own farm truck to haul it, it’s only $145. I’ve also budgeted an additional $40 for a 7ft deer fence and landscape fabric. For my family of 4, I am willing to count this raised bed garden as a worthwhile investment of time and money.

Have you used any interesting materials to create a raised bed garden? Do you have questions about a material that you can use to create a garden this season? Ask your gardening questions here or share your story in the comments.

By Ashley Bodkins, Senior Agent Associate and Master Gardener Coordinator, Garrett County, Maryland, edited by Christa Carignan, Coordinator, Home & Garden Information Center, University of Maryland Extension. See more posts by Ashley and Christa.

Blueberry success is all in the soil

February 19, 2021June 8, 2022Maryland Grows4 Comments

Farmers and gardeners learn much by daily tending soils and plants. But the winter “off-season” affords us time to dig deeper into topics of interest and learn from co-cultivators and experts in the field. I spent some time in a variety of grower meetings, conferences, and webinars in January and February where research findings were shared. Many gardeners are interested in growing blueberry so in this article I’ll share tips for success including some insights I picked up from presentations by Oregon blueberry researchers David Bryla, Ph.D. (USDA) and Bernadine Strik, Ph.D. (Oregon State U.)

Blueberry background

Highbush blueberry plants evolved to grow in low pH, high organic matter sandy soils with high water tables. These soils contain more ammonium nitrogen than nitrate nitrogen, hence blueberry’s preference for the ammonium form of plant-available nitrogen. The shallow, fibrous root system grows almost entirely in the top 12 inches of soil. Most of the roots are very fine, the width of a human hair, and can’t penetrate or thrive in clayey, compacted soils. The key to success is create garden conditions that mimic those in blueberry’s natural environment.

Blueberry thrives in well-drained, porous soils, high in organic matter (4% – 20%). The soil pH should be in the 4.5-5.5 range.

Soil preparation starts in fall

Begin by testing the soil in the late summer or fall prior to spring planting. For gardeners, soil testing labs provide the most accurate pH measurement of your soil, as well as baseline information on organic matter and nutrient levels. pH probes sold to gardeners are generally inaccurate and pH color kits using litmus paper are only accurate to ½ of a pH unit (5.5, 6.0, 6.5, 7.0, etc.

Add organic matter

The top 12 inches of soil should be one-third to one-half organic matter by volume. Peat moss (3.0-4.5 pH), plant-based compost (7.0-7.5 pH), and lightweight potting soil, a.k.a. soilless growing media (5.5-6.5 pH) are the materials most often mixed into the soil. Research has shown that adding compost (especially animal manure compost) can increase soil pH.
Some Oregon growers incorporate 2-3 inches of aged softwood sawdust into topsoil prior to planting. The benefit is that sawdust has a low pH, decomposes slowly, and increases organic matter levels. For Maryland gardeners, large amounts of sawdust are difficult to come by, but bark fines are readily available. You would need to apply 1.0 lb. of additional ammonium sulfate (21-0-0) per 100 sq. ft. nitrogen for the soil microbes that slowly decompose the bark fines.

Lower soil pH

Elemental sulfur is applied (based on soil test results) in the fall prior to spring planting, and incorporated to a 6-8 inch depth.
Pelletized and prilled forms of sulfur are easier to apply than powdered sulfur but take longer to lower soil pH.
An oxidation process, driven by special soil bacteria, converts the sulfur to sulfuric acid, releasing hydrogen ions that lower soil pH. The bacteria are most active in warm, moist soils. The process takes 6-12 months. Iron sulfate can also be used to lower soil pH but 6 times as much is required, increasing the cost.
Re-test soil pH to monitor pH levels and apply sulfur as needed to maintain the 4.5-5.5 range.
For container blueberry plants, mix 3 TBS. of sulfur into the top few inches of growing media, for a 15-gallon container, to reduce the pH by one unit (e.g. from 7.0 to 6.0).

Bag of sulfur — Elemental sulfur is available in powdered and pelleted forms

Fertilizing

Ammonium sulfate fertilizer is recommended because it supplies nitrogen in the ammonium form and helps acidify the soil.
Fertilize at full bloom and again three weeks later.
Urea is another good nitrogen source, recommended when soil pH is below 5.0 because it is only one-half as acidifying as ammonium sulfate. The nitrogen in urea is converted to ammonia and then to ammonium.
Oregon research studies show that feathermeal (12-1-0.5) and soluble fish fertilizers (4-1-5) work well in organic blueberry production. Organic growers prefer to inject fertilizers into irrigation water, known as “fertigation.” Another interesting finding was that there were no significant yield differences between the lowest (20 lbs./acre) and highest (240 lbs./acre) nitrogen fertilization rates.
Organic matter and organic fertilizers release ammonium ions with relatively little oxidized to the nitrate form as long as soil pH is in the 4.5-5.5 range. When soil pH is >6.0 most of the nitrogen from decomposing organic matter will be converted to the nitrate form with negative effects on plant growth.
Oregon research indicates that organic acids (humic and fulvic) applied in liquid form, increase blueberry root growth while lowering soil pH.

Developing blueberries — Blueberry fruits developing

Watering

Blueberry root systems need to be kept moist. Plants can tolerate hot weather but not drought. Water your blueberry bed thoroughly and consistently when rainfall is lacking. Soaker hoses and drip irrigation work well.
Blueberry grows and produces best when the pH of irrigation water is <7.0. Commercial growers often acidify irrigation water to maintain low soil pH. The pH of municipal water in our region is typically 7.5-7.8 and has a high salts and bicarbonate content. Just be aware that your irrigation water can drive up soil pH.

Mulching

Blueberry roots cannot compete very well with weeds for nutrients and water. Mulch is essential to keep soil cool, improve water infiltration, conserve soil moisture, reduce weeds, and increase organic matter.
Use aged wood chips (never fresh), shredded bark, pine needles, or sawdust as a mulch. These materials are low in pH (4.5-5.2) and salts, and decompose slowly.
Interestingly, a recommended growing system in Oregon uses strips of heavy-duty weed barrier to cover beds after they have been mulched to further reduce weed growth and moisture loss.

A well-planned and maintained blueberry bed can produce well for 20+ years. Start yours in 2021!

Resources:

Lowering Soil pH for Horticulture Crops. Purdue Extension

Organic Blueberry Research– eorganic.org

Author: Jon Traunfeld, Extension Specialist

Garden cleanup and soil improvement

October 16, 2020May 11, 2023Maryland Grows2 Comments

Food gardens are in transition in October. Cool-season crops hit their stride and cover crops replace tired warm-season crops. Rather than put the entire garden to bed we may decide to coax more food from the ground with row covers, cold frames, and over-wintering crops. Either way, fall cleanup (“garden sanitation”) and soil protection and improvement this fall help ensure a healthy and productive garden next year.

Cleanup Tips:

Remove stakes, trellises, hoses, temporary fences, plant labels, and other gardening materials.

Clean up and remove all above-ground plant residues. Many diseases can survive over the winter on small pieces of leaves and stems. Some pest insects will hunker down under protective layers of dead weeds and crop debris. Either bag up and dispose of these plant wastes or compost them. All parts of the bin or pile must heat up to >140⁰ F. to kill plant pathogens and weed seeds. (Japanese stiltgrass should be bagged up with regular trash for landfill disposal.)

Empty the growing media from container gardens and store it in a trash can or heavy-duty trash bags. Soil-less growing media and compost lose nutrients and break down physically over time. Mix last year’s growing media 50:50 with fresh growing media and/or compost next year.

Soil Protection and Improvement Tips:

Instead of pulling plants out of the ground, cut them off at ground level leaving the root system intact. This reduces soil disturbance while adding organic matter.

Don’t leave the soil bare. Cover it with shredded leaves or some other type of mulch to prevent erosion. Rake leaves into a loose pile and mow over them with a lawnmower to cut them up. They will be much less likely to blow away if they are broken up. The leaves will reduce weed growth and can be retained as mulch next spring.

It’s getting late for planting cover crops. If you have seed, you can take a chance on sowing before the end of October. The soil temperature should be at least 45⁰ F. to 50⁰ F. for germination of cover crop seed. You can enter your zip code to learn the approximate temperature of soil in your area.

Bury plant-based food scraps in garden soil. This keeps them out of the landfill and recycles plant nutrients in the root zone. Unfenced gardens may attract wildlife.
As much as possible, use organic matter generated from your yard and household. Organic matter brought in from outside sources carries potential risks. Manure, straw, and hay may be contaminated with long-residual phenoxy herbicides or troublesome weed species.

Invasive jumping worms have been appearing more frequently in gardens and landscapes. They are spread by the movement of soil and organic matter like mulches.

Asian jumping worm — Invasive jumping worm removed from a deep layer of garden leaf mulch.

Test your soil. For $15-$20 you can have an accredited lab test your soil. You’ll get some important baseline information on soil pH, nutrient levels, and organic matter. Lead testing is included with some basic soil tests (e.g., University of Delaware). Most vegetable and fruit crops grow best in 6.0 to 6.8 pH soils. If your pH is too high or too low some nutrients may become unavailable to plants, causing deficiency symptoms, or overly abundant, causing toxicity symptoms. If recommended by the lab, you can apply lime or sulfur to your soil this fall so they can start changing soil pH.

By Jon Traunfeld, Extension Specialist. Read more posts by Jon.

Serpentine Soils Are Anything But Barren: They Support a Unique Grassland Habitat

December 30, 2019April 19, 2024Maryland Grows3 Comments

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.

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 myriad birds species (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.

*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.

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

Improve Your Soil by Growing Soil Microbes

March 15, 2019June 29, 2022Maryland Grows3 Comments

As a non-soil scientist who loves to explore and learn about soil, I was quite shocked to read last year that humus, as it’s commonly understood, does not exist in nature.

What, no humus? How can that be? What is it then that makes up the bulk of soil organic matter? This fascinating story unfolded for me through an excellent 4-part soils podcast (“Priming for Production”) produced by Natalie Lounsbury in November 2017. The podcast can be found on Natalie’s notillveggies.org website which was funded with a Northeast SARE grant. (Hey, Master Gardeners, these podcasts count for Master Gardener continuing education hours!)

At the beginning of Episode 3 of the podcast (What is soil organic matter, really?) Natalie states “Our understanding of soil organic matter is undergoing something of a revolution right now.” I was about to have my mind blown. Continue reading →

Q&A: What kind of soil should I use in raised beds?

February 8, 2019February 6, 2019Maryland Grows2 Comments

raised bed garden — *Raised bed garden. Photo: Pixabay*

Q: I plan to build four raised beds for vegetable gardens in the spring. I need to purchase garden soil to fill these beds. What kind of soil should I use in raised beds? What do I look for when shopping for garden soil?

A: Try to locate a landscaping business or garden nursery that sells a compost-topsoil mixture. If you purchase topsoil with no added compost, plan on working in at least two inches of compost.

Maryland does not have regulations that set standards for topsoil sales. Go to a reputable nursery or topsoil dealer. Ask questions about where the soil comes from, what kind of soiling testing is performed, what the pH is, and whether anything has been added to it. Examine the soil before purchasing it.

Topsoil should be dark and crumbly with an earthy smell. Do not purchase soil that is foul smelling, mottled gray, or chalky in texture. Examine the soil again before it is unloaded at your home.

Learn more about soils and compost on the Home and Garden Information Center website.

By Ellen Nibali, Horticulturist, University of Maryland Extension Home and Garden Information Center. Ellen writes the Garden Q&A for The Baltimore Sun.

Naked garden soil is not cool: Keep it covered this winter

October 19, 2018September 16, 2022Maryland Grows5 Comments

Plant and animal existence depends on healthy, functioning soils but humans too often treat it like dirt. We can improve soil health in gardens and on farms by:

limiting soil disturbance (tillage)
planting a diversity of plant species
keeping soil covered throughout the year

These practices reduce erosion and nutrient run-off, build organic matter, and increase carbon storage in soils which helps mitigate the effects of climate change.

Leaf Cover

A thick layer of leaves (preferably run over with a mulching mower) is a terrific winter cover for small vegetable and flower beds. Bags of leaves from your yard or from neighbors’ yards are plentiful this time of year and allow us to sustainably recycle nutrients.

Whole leaves protecting soil and garlic plants. — Whole leaves protect soil and garlic plants.

Try a Living Cover This Fall

We’ve had a number of relatively warm falls in recent years and can expect a continuing lengthening of the growing season as a result of global warming. We are past the recommended best date for sowing winter cover crops in Maryland. However, if you live in Central or Southern Maryland or on the Eastern Shore I think you can risk sowing winter rye or winter wheat with a legume, either crimson clover or hairy vetch, through the end of October. The soil and air temperatures should remain sufficiently high for germination and root establishment. Continue reading →