soil testing

How to grow a healthy garden

March 24, 2023July 17, 2023Maryland GrowsLeave a comment

It’s easy to get overwhelmed by the sheer volume of gardening advice in books and websites. So I thought I’d simplify things by sharing my top 10 tips for keeping a garden healthy.

Start with your soil. Healthy soil grows healthy plants. So get a soil test to know what you have and need.

Add compost or other organic matter regularly to enliven the soil and keep the soil community happy. This intricate web of beneficial microbes, fungi, bacteria, worms, and more is crucial to healthy plants.

Well-adapted native plants such as this white penstemon naturally resist pests and disease. Photo: Kathy Vesely

Minimize soil disturbance. Every time you turn the soil, you bring up weed seeds and wreak havoc on the soil community. So dig and till minimally.

Keep the soil covered with plants, an organic mulch, or cover crops. Bare soil invites weeds, encourages soil-borne disease, and promotes erosion.

Put the right plant in the right place. Choose plants that suit the site whether it’s sunny or shady, wet or dry. This matchmaking helps plants not only survive but thrive.

Use native plants. These tough, well-adapted plants need less water and fertilizer. Since they co-evolved with native wildlife, they support pollinators and other native species best.

Encourage beneficial insects. These are the good bugs that help control bad bugs. Nine out of ten insects are beneficial, naturally controlling the few true pests. Put them to work for you.

How? Reduce or eliminate chemical pesticides which kill both good and bad bugs. Use organic products instead and try other controls like hand-picking or floating row covers.

Further, encourage beneficial insects by planting a wide variety of plants to provide food and shelter. Add a rock to a birdbath so insects can sip.

Wait to cut back perennials and grasses until spring to give beneficial insects a safe place to overwinter. Many tuck into hollow stems or leaf litter.

Check your plants often. When you’re strolling, be patrolling. Look for spots, yellowing, or other changes that might be clues to a problem. Early detection makes fixes easier.

If you live in Washington County, Maryland, e-mail or call me if you need help identifying an insect or disease. Just send me a photo or bring me a sample. If you live in another area of Maryland, contact your county or city Extension office, or send your questions to Ask Extension.

Many problems are preventable. Honest. About 80% have cultural or environmental causes and aren’t due to pests or diseases. So there’s much we can do to prevent problems.

Water wisely. Water in the morning and avoid overhead watering. Leaves that are wet overnight tend to have fungal problems.

Removed diseased plants. Add compost which naturally suppresses some diseases. Space plants so air circulates. Cover bare soil so rain doesn’t splash fungal spores up onto plants.

At the end of the growing season, thoroughly clean up vegetable plant debris which can harbor harmful overwintering insects and disease.

There you have it, my top 10 tips for a healthy garden. When you work with nature, not against it, you naturally limit pests and diseases, grow more resilient plants, and build a healthier garden and community.

That’s a very good feeling indeed.

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.

How to soil test and actually utilize the results – a challenging task

June 27, 2022July 13, 2022Maryland Grows2 Comments

As a newer gardener, I have not previously gotten around to using soil test information. I’ve been planning an ornamental overhaul in a small area of my yard and wanted to soil test to make sure the plants added to the area had the best chance of success. The HGIC website has a lot of soil test information, but I’ve never looked at it closely myself until now. Even though our content is well-written and organized, the subject is intimidating with many choices to make, multiple steps, math homework to figure out how much fertilizer to use in your space, and as I learned, many caveats or roadblocks. I can see plenty of people just giving up and not adding any soil amendments, or just going to the hardware store and buying a bag of fertilizer and applying without thinking too much about it.

Even after reading our material thoroughly, I still needed several questions answered from our experts. I’ve got a handle on it now, for the most part. With this post, I hope to detail how I figured out what fertilizers I needed, how to apply it, and then the most important things I learned that I didn’t feel are made clear.

The goal

I’ve got this space in my backyard that wasn’t being used for much. In the summer of 2020, mid-pandemic, pre-offspring, I decided to revisit a teenage hobby of mine – remote control cars. I took a shovel and cleared out an area and built ramps and hills out of dirt, for my very-own mini-dirt track. 2 years later, my wife asks me “are you going to keep the track? It’s ugly.” So, my task is to beautify it with improved landscaping and added vegetation. We also have a bunch of hostas in our front yard garden that keep getting eaten by deer. Our backyard is smaller and enclosed, so we hope the hostas will avoid attack in their new backyard, trackside location. We are also adding other plants good for shade conditions.

The location is on a bit of an incline, with the higher elevation area being more sandy and rocky, and the bottom softer and wetter. There is an “infield” of the track that is often stood on that is grass, but has been overtaken with weeds. I am planting nice plants and shrubs around the outside, and re-seeding the infield with grass. Since I know from a lot of digging to make the track that the soil is quite different in different areas, I wanted to soil test so that I could find out what exactly I might need to do to make sure the plants have the soil they need in their different locations.

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What is soil pH and does it really matter to plants?

May 25, 2022August 11, 2023Maryland Grows3 Comments

Well, the short answer from a soil nerd (please note soil nerd is not the same as a soil scientist or soil chemist) is that yes it really does matter! Have you ever done the experiment with boiling red cabbage leaves and used that as a pH indicator? It’s a fun science experiment but probably wouldn’t work for determining an accurate soil pH.

People do not always see the benefit of getting their soil tested; however, if you take a good comprehensive soil sample, the information that you get from the analysis is invaluable. Not only will the results keep you from over-applying nutrients, which has economic and environmental benefits, but also it will ensure that your plants have all that they need right at their root tips.

In my opinion, the most helpful piece of information gained from conducting a soil analysis is the soil pH. PH is a measure of hydrogen ion concentration and tells you how acidic or basic/alkaline the soil is. Most vegetable garden plants prefer a pH between 6-7; therefore, acidic soils need to be amended with calcium carbonate (limestone). Acidic soils are indicated with numbers below 6 on the pH scale which ranges from 0 to 14. Soils in the Eastern US are often acidic, but the natural pH will depend on parent material and other soil factors, such as how the soil has been managed, what plants are growing there, etc.

It should be noted that some plants actually prefer acidic soils, such as rhododendron, azaleas, and blueberries. Also, some plant diseases, such as scab in potatoes, are worse at a higher pH. Lowering soil pH (often done by adding sulfur) can take several months and may need to be a multi-step process. It is a great idea to test garden soils in the fall, so pH-altering amendments have time to do their job. Here is a great cheat sheet to help you understand what your soil analysis results mean.

tomato plant with yellowing leaves on the bottom portion — Blueberry. Photo: C. Carignan

Another reason that pH is important is that it helps determine the availability of soil nutrients. Soil pH is linked to Cation Exchange Capacity (CEC), which is influenced by soil particle size and the type of parent material (rock). Clay soils will have a higher CEC (sites to hold onto nutrient ions) than sandy soils. CEC will be reported on most soil analyses. If the pH is not in the correct range, then many nutrients are not available to plants, even if you have applied ample nutrients. Thus, in order for the nutrients to support plant growth, it’s important to get that pH correct! This will provide both economic and environmental savings. Check out this link for a neat chart showing nutrients available and pH.

The third reason that it is important to check pH is because it can affect soil microorganisms, which are going to thrive at a near-neutral level. If the pH is too high or too low you will see a decrease in the number and activity of good soil bacteria, fungus, and more that help to break down organic matter and do amazing other things in the soil profile. (For more details on this topic, download PDF – Soil Acidity Impacts Beneficial Soil Microorganisms, from Washington State University Extension.)

Common questions about soil pH

Can pH change from year to year?

Some forms of nutrients —commercial fertilizers, compost, composted animal waste (cow, horse, pig, chicken manure), organic matter, the weathering of rocks, and even rainfall can alter pH. Fertilizers, depending on the type used, will alter soil pH at different rates. Refer to this PDF – Fertilizers and Soil pH from the University of California.

Can I use a home soil Testing kit?

I normally steer people away from these types of kits, just because there are so many inaccuracies, especially, if the kits were not stored at the proper temperature and the directions are not followed correctly, then the results may not be 100% accurate.

What about electronic soil testing probes?

I don’t have first-hand experience with these probes. I am sure that they do have a level of accuracy; however, I cannot justify the upfront cost. For most gardeners, soil testing every 3 years is sufficient, so in my opinion, it is easier to just collect the sample and send it to a laboratory.

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.

This year, the University of Maryland Extension Master Gardener Grow It Eat It Program celebrates the resource that supports all life on earth – soil! Look for soil education programs offered by your local Master Gardener program, and visit the Home & Garden Information Center website for more information about soil health.

Are you looking at my soil?

April 27, 2022May 11, 2022Maryland Grows1 Comment

As a first-year college student studying horticulture (and later agronomy) I had no idea what I was in for when I signed up for that first Introduction to Soil Science course. Growing up, gardening and working on my family’s dairy farm, soil was something that we often talked about, mainly if it was wet or dry, rocky or smooth, and of course to stay out of the garden when it was wet; however, I really didn’t understand how important managing it was or how many different parts could be studied!

The technical definition of soil is the natural body composed of solids, liquids, gasses, and living matter that is capable of supporting plant life and has properties resulting from the five factors of soil formation. Wow! A mouthful of words, but a key point from this definition is the word NATURAL— soil is what covers the earth naturally and helps to absorb and disperse solar radiation and precipitation. It also provides an anchor for plant life. With harsh treatment, this living portion can be damaged and thus can take many years to build back. It is important to know too that healthy soils help to mitigate climate change as they store a huge amount of carbon in the form of carbon dioxide (CO2) and organic matter.

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Seed starting and soil testing: a Master Gardener outlines his spring gardening progress

March 1, 2021July 29, 2022Maryland Grows5 Comments

In mid-February, I started my Gypsy, Monty, and Green Magic broccoli, Snow Crown cauliflower, Lacinato kale, several types of lettuce, and some Big Blue salvia.

Italian flat-leaf parsley was started in mid-January. Most of these transplants will be planted in the garden or containers in the first week of April after hardening off for at least a week in my cold frame. My pre-sprouted snap peas will be planted in late March. Planting dates for central Maryland can be found here on the Home and Garden Information Center website.

In early March, I will be making a trip into Baltimore to get some other seeds for Sugar Ann snap peas, Jade string beans, and a couple of other things. In late March, I will be planting some seed potatoes in containers, just to see what the yield is. On March 27^th, seven to eight weeks before the spring plant out date of mid-May, I will be planting Galine eggplant and several different types of peppers.

In previous years, I’ve planted tomatoes six weeks prior to my plant out date, but they have been leggy. This year, I’m planting them on April 10 for planting in the garden and containers on May 15.

My latest soil test, done in May of 2019, says to incorporate one pound of nitrogen (N) per 1,000 square feet. Only N is required since the beds contain the optimum amount of phosphorus (P) and potassium (K) and are at the correct pH.

To determine what fertilizer needs to be added to my beds which are 32 or 40 square feet, I will have to convert this recommendation to determine the amount of urea (46-0-0) to apply to my beds. This is fairly simple to do, using the following equation. Amount of N/.46 (% of N in urea) x beds size/1000 square feet. This yields the following: 2.17 pounds of urea x 0.032 for a 32 square foot bed equals .069 pounds of urea or 1.1 ounces. I guess I’ll have to get out my kitchen scale.

Alternatively, the University of Delaware suggested 2.5 pounds per 1000 square feet or 2.5 x .032 = 1.28 ounces of urea. This calculation works for almost all recommendations from soil test labs. However, if in doubt, you can always Ask a Gardening Expert at HGIC.

By Kent Phillips, University of Maryland Extension, Howard County Master Gardener

Building healthy soil is the key to healthy plants

February 26, 2021February 16, 2021Maryland GrowsLeave a comment

Healthy soil grows healthy plants. If you want a vigorous, productive garden, protect and improve your soil.

Soil is made up of minerals, air, water, and organic matter. This skin of the Earth anchors and grows our food, filters our water, and recycles vital nutrients like carbon.

How do you build healthier soil? You feed it.

Compost, chipped leaves, untreated grass clippings, and other organic amendments can be turned in or used as mulch. Cover crops can be planted in the fall and turned into the soil in spring.

This organic matter lightens heavy clay soils. It improves soil structure. It helps the soil hold water and nutrients. It helps to suppress disease and feeds beneficial soil organisms.

Yes, soil is alive. An intricate community of microbes, fungi, beneficial insects, worms and more lives beneath your feet. Keeping this gang happy helps your plants growing their best.

That’s why we discourage tilling. When you till, you disturb the soil community, literally turning their world upside down. You also damage soil structure and bring weed seeds to the surface.

So till less or not at all. Instead, use a garden fork or broadfork to gently loosen soil, if needed. Broadforks are simply wide forks you rock to aerate soil.

How else can you improve your soil? Get a soil test. For $10 to $15 you can find out just what fertilizer your soil needs – and doesn’t need.

Soil tests can save you time and money and keep excess fertilizers out of our waterways.

Getting a soil test is easy. Download everything you need at the Home & Garden Information Center website.

Next, go deep. Scoop a few soil samples in your garden, going at least 6 inches down. Mix the sample and let it dry. Scoop a cup or two into the bag, box it up, and mail it to a lab.

You’ll have your results in a week or two. The test will tell you your soil’s pH, nutrient levels, and percent of organic matter. You’ll also get specific fertilizer recommendations for what you’re growing.

You can also help keep soil healthy by not walking on it, especially when it’s wet. That causes compaction. Air, water, nutrients, and roots have a tough time moving through dense soil.

Instead, create paths or strategically place stepping stones so you can walk between rows of plants.

I know you’re eager to garden, but don’t work wet soil. This also causes compaction.

To test if your soil is dry enough to work, grab a handful of and squeeze it into a ball. Now, bounce it gently. If it stays intact, your soil is too wet to work. If it crumbles it’s ready.

And never, ever till wet soil. That wrecks its structure and the soil community. Think Armageddon.

Great gardens grow from the bottom up. Protect and improve your soil to ensure it rewards you with year after year of productive plantings.

Maryland Grows

UMD Extension Home and Garden Information Center Blog