Building Your Garden from the Ground Up: Basic Tips for Improving Garden Soil Quality
You’re dreaming of spring, eager to grow a gorgeous garden filled with fresh food and beautiful blooms. But before you sow your first seed or order perennials from your favorite nursery, take the time to dig deep into your soil. Understanding your soil’s fertility and improving its quality is the first step in creating a thriving, vibrant, and productive garden. Learning the ins and outs of soil prep may not seem as sexy as filling beds with fabulous flowers or delicious veggies, but understanding your soil—and its hidden secrets—will help you create a spectacular garden.
Are you ready to learn soil basics? Let’s dig in!
What’s So Exciting About Soil?
The health of your garden’s soil directly impacts the health of your plants. Think of it this way: we feed children with nutritious food so they’ll grow healthy and strong, right? It’s important to feed our green babies well, too—and soil provides the nutrients they need to bloom beautifully, fight disease, and produce abundant harvests. If we give plants a depleted diet without access to key nutrients, they can’t live up to their potential—and you risk a disappointing gardening season.
Here’s the great news: creating excellent soil is easier than you think! All you need is a little information and a bit of time and effort to uncover the mysteries of your garden’s soil. Once you know what you’re working with, it’s like solving a riddle: you’ll have the answers you need to create the best soil for your garden.
Soil Basics 101: Know Your Soil
Do you really know your soil? Is it clay, loamy, or sandy? Is it acidic or alkaline? Does it contain the nutrients your plants need to thrive? Whew—getting to know your soil sounds daunting, but don’t worry! It’s easy to become well-acquainted with your soil, discovering its great qualities and correcting its less-pleasing traits.
“Know your soil,” says Jessie Keith, Horticulturist and Communications Specialist of Black Gold, a leading North American supplier of growing mixes. “Find out its pH. Look at its tilth and aeration. Understanding your soil is so important to gardening success.”
One of the first steps is to look at the soil’s structure. Dig up a handful of soil and examine its texture. All soil is a mixture of mineral particles—clay, sand, and silt—that affects drainage, density, and the ability to hold nutrients. Each type of soil interacts differently with plants. How do you know what soil fills your garden beds? It’s time to get your hands dirty! Rub the soil between your fingers. What does it feel like?
Tips to Determine Soil Type:
Feels: Hard when dry; sticky when wet
Pro: Tiny, dense particles hold large reserves of moisture and nutrients
Con: Drains slowly and can become compacted when dry
Feels: Gritty to the touch
Pro: Large particles allow water to flow through easily
Con: Nutrients also flow through the particles, but too quickly
Feels: Slippery when wet; like talcum powder when dry
Pro: Fine particles packed tightly together hold nutrients
Con: May inhibit drainage and air circulation
Garden Goal: Loam Soil
Loam is the gold standard for soil! A combination of clay, sand and silt particles in relatively equal amounts, garden beds rich in loamy soil provide the perfect start for your plants.
Loam is ideal for most plants because it holds plenty of moisture but also drains well, allowing sufficient air to reach plants’ roots. It’s rich in humus (what’s left after organic matter decomposes), making a perfect environment for microorganisms that help plants thrive.
Take a Test
Once you know what type of soil fills your garden beds, it’s time to test your soil. For about the price of a cappuccino, you’ll receive a detailed analysis of your soil: its pH, the nutrients, and even what amendments you may need to add to grow the specific plants you desire. Many university extension services provide soil tests*. Simply dig a bit of soil from several areas in your garden, mix it together, and send the sample to the university for analysis. Check with your local university’s extension service to see if they offer soil testing.
*In the United States. In Canada and elsewhere, you should consult your local garden center.
DIY soil test kits are also available online or in stores, offering a quick way to learn your soil pH.
Sometimes, general soil pH—acidic or alkaline–is apparent by what’s currently growing in your garden. “Look at plant material,” says Keith. “Often, when you see what grows well in your soil, like native rhododendrons, for instance, it’s an indication of what plants in the same family or with the same soil needs will grow well, like azaleas and blueberries.”
Why Does Soil pH Matter?
Soil pH is one of the most important factors to determine soil fertility. Ranging from 0 to 14, 7 is considered neutral, under 7 acidic, and above 7 alkaline. Most plants grow well in a slightly acidic soil pH of 6-7, and many plants tolerate a wide range. Knowing the soil pH determines which nutrients are available to plants. Nitrogen, phosphorus, potassium, calcium, and magnesium—all important nutrients for plant growth and health—dissolve well and are easily accessible to plants in slightly acidic soil. If the pH is too acidic or too alkaline, plants may get an overabundance of some nutrients and not enough of others.
Some plants, like azaleas and blueberries, for example, need acidic soil to thrive. Make sure to look up the pH needs for the plants you want to grow in your garden. You may need to amend the soil pH significantly for them to grow well.
Soil Basics: If your soil pH is too low (acidic), add garden lime to the bed. If the soil pH is too high (alkaline), add powdered sulfur to the soil.
Improve Soil Structure
Depending on what type of soil you’ve identified in your garden, you may need to amend its composition. Clay soil, for instance, needs organic matter added to it to improve drainage and aeration. Adding organic matter to existing clay soil helps loosen the structure, releasing minerals that become sticky when the clay is wet or hard when dry. Likewise, organic matter improves the water-holding capacity of sandy soil, helping it retain nutrients, too. Plants need access to these nutrients to grow.
Organic matter, such as compost, rotted manure, or fallen leaves, not only improves the structure of the soil, but it also provides a rich supply of slow-release nutrients for plants. Additionally, organic matter supplies food for beneficial soil organisms. Amend poor soil with organic matter, and let nature feed your garden. The materials break down and feed the soil, which in turn feeds your plants, reducing the need for commercial fertilizers.
Work organic matter into the soil using a garden fork, mixing it 4 to 6 inches (1deep into existing soil. Vegetable gardens benefit from the addition of organic matter each season, as many veggie plants feed heavily to produce their crops. Perennial beds are a little trickier: after all, you don’t want to damage plant roots by digging in soil amendments. Instead, side-dress perennials with finished compost, or add organic matter into the soil when you divide perennials. They’ll appreciate the natural nutrient boost.
To till or not to till? If you’re starting a garden bed from scratch, you may need to use a tiller to break up compacted soil and add organic matter. However, tilling can encourage the growth of dormant weed seeds brought to the soil’s surface, exposing them to light. Tilling also disturbs earthworms, who aerate the soil naturally and interferes with microorganisms. If it’s a relatively small space, opt for a good workout with a garden fork or spade instead!
Feed the Organisms that Feed Your Soil
Soil teems with life that benefits your garden. Earthworms, insects, fungi, and beneficial bacteria all convert organic matter, like dead leaves and plant debris, into nutrients for plants. They also help aerate the soil and convert organic matter into humus. When you amend the soil with organic matter, you’re actually feeding a whole ecosystem that ultimately provides the nutrients needed by your plants.
Along with adding organic matter to your soil, keep the soil evenly moist and well-aerated to provide the most hospitable environment for microorganisms. A soil basics tip: Avoid using harsh pesticides on your plants, because of the chemicals runoff into the soil and harm beneficial insects and microorganisms.
Protect Your Soil
You’ve done all the beginning soil basics like added organic matter, checked your pH, and your garden is ready to plant. Make sure to protect your hard work by caring for your soil!
Create beds that you can easily reach into without stepping on the soil. Walking on garden soil can compact it: exactly what you corrected by adding organic material! Instead, create pathways through the garden, where you can easily reach into beds to plant, weed, and harvest, without stepping on the soil. A four-foot-wide (1.2 m) garden bed allows you to reach the center of the bed from either side—without walking on the soil.
After planting, mulch garden beds to retain soil moisture and prevent weeds. Mulch also adds organic matter to the soil without disturbing the plants’ roots as it breaks down over the season. Spread mulch over the soil, around the plants’ stems, and let it decompose and feed your soil naturally. Mulch also helps keep garden soil cooler during the summer months and protects roots during freezing winter days.
When the growing season ends, consider adding green manure to vegetable garden beds. This living “mulch” protects the soil’s surface, prevents erosion, increases organic matter and nutrients, and maintains or improves the soil structure. Green manures include legumes, grasses, other cover crops, which are then cut and mixed into the soil to add organic matter and nutrients for a new garden season.
Rise Above Bad Soil with Raised Beds
Improving garden soil isn’t an overnight process. It may take several seasons of amendments until you enjoy the soil of your dreams. If, after testing your soil and checking its structure, you feel frustrated, don’t worry: rise above your bad soil! Raised beds offer every gardener the chance to start from scratch with perfect soil. Simple raised beds provide a frame to grow whatever you like—and the ability to control the contents of your soil. Whether you choose to create your own mix of topsoil, compost, and peat moss or purchase commercially-prepared raised bed mix, like Black Gold’s Natural and Organic Raised Bed and Potting Mix, raised beds provide nearly instant gratification for an eager-to-plant gardener.
With raised beds, you can start growing ingredients for your favorite summer bruschetta or garden-to-vase bouquets instantly, while still amending your existing garden with these soil basics tips. Just think of how many gorgeous plants you’ll grow next year with your superbly amended soil!
Give these soil basics a try and your garden will be amazing this year!
This post on Victory 2.0 Soil Basics is provided as an educational/inspirational service of the National Garden Bureau and its members.