Understanding Nutrients in the Garden
Healthy plants need more than sunlight and water. They also rely on essential nutrients to grow, produce flowers and fruit, and withstand environmental stress. Most nutrients are absorbed through the roots from the soil, while carbon, hydrogen, and oxygen come primarily from air and water.
What Are Plant Nutrients?
Plants require 17 essential elements to complete their life cycles. These nutrients are often grouped by the amounts plants need—not by how important they are.
Primary nutrients
- Nitrogen (N) supports leafy growth and is part of chlorophyll, the pigment plants use to capture light.
- Phosphorus (P) plays a role in energy transfer, root development, and seed formation.
- Potassium (K) helps regulate water movement and supports many processes involved in plant health.
These are called primary nutrients because plants generally use them in relatively large amounts. They are the three numbers shown on a fertilizer label, such as 10-10-10.
Secondary nutrients and micronutrients
Plants also need calcium, magnesium, and sulfur in moderate amounts. Micronutrients—including iron, manganese, zinc, copper, boron, molybdenum, chlorine, and nickel—are needed in smaller quantities. “Micronutrient” does not mean unimportant: a shortage or excess of even a small amount can affect plant growth.
How Soil Provides Nutrients
Soil supplies nutrients as minerals and organic matter break down. Soil organisms help recycle nutrients, while organic matter can improve soil structure and its ability to hold water and nutrients. Nutrient availability also depends on soil conditions. For example, soil pH affects how readily plants can access certain elements.
Plants may show signs of nutrient stress, such as slow growth, yellowing leaves, or poor flowering. These symptoms are not always caused by a nutrient shortage. Overwatering, drought, pests, disease, compacted soil, and unsuitable pH can create similar problems.
Start with a Soil Test
A soil test is a practical way to learn what your garden needs. Testing can identify soil pH and levels of selected nutrients, helping gardeners avoid unnecessary fertilizer applications. In New Jersey, residents can contact Rutgers Cooperative Extension for information about soil testing and sample submission.
Follow the testing instructions carefully and collect soil from several spots in the area being tested. Different parts of a property may have different soil conditions, so vegetable beds, lawns, and ornamental gardens may need separate samples.
Using Fertilizer Wisely
Fertilizer can supply nutrients, but more is not necessarily better. Applying too much can damage plants, disrupt soil conditions, and allow nutrients to wash into storm drains and waterways. Use fertilizer only when there is a demonstrated need, and follow the product label for the correct amount, timing, and application method.
Compost and other organic materials can contribute nutrients and improve soil. Their nutrient content varies, however, so they should not be treated as an exact substitute for a soil test or a carefully selected fertilizer when specific nutrients are needed.
A Balanced Approach to Plant Nutrition
Good plant nutrition begins with suitable plants, healthy soil, and appropriate watering. Choose plants adapted to your site, add organic matter when needed, protect soil from erosion, and test before making major nutrient changes. These steps support vigorous plants while helping protect the wider environment.
6 Simple Tips for a Nutrient-Rich Diet
- Eat a variety of colorful fruits and vegetables.
- Choose whole grains for fiber and key nutrients.
- Include protein-rich foods at each meal.
- Get calcium from dairy or fortified alternatives.
- Choose healthy fats from nuts, seeds, and fish.
- Drink water and limit sugary beverages.
Eat a variety of colorful fruits and vegetables.
Eat a variety of colorful fruits and vegetables to get a broad mix of nutrients. Different colors often signal different vitamins, minerals, and beneficial plant compounds, so include a range of options—such as leafy greens, red berries, orange carrots, and purple cabbage—in your meals. Fresh, frozen, and canned produce can all be nutritious choices; when selecting canned options, look for products with little or no added salt or sugar.
Choose whole grains for fiber and key nutrients.
Choose whole grains such as oats, brown rice, whole-wheat bread, and quinoa to add fiber and important nutrients to your meals. Fiber supports healthy digestion and can help you feel full, while whole grains also provide vitamins, minerals, and other beneficial compounds. Check ingredient lists for “whole grain” or “whole wheat” as the first ingredient, and try swapping refined grains for whole-grain options in familiar dishes.
Include protein-rich foods at each meal.
Include protein-rich foods at each meal to help support muscle health and keep you feeling satisfied. Choose options such as eggs, beans, lentils, fish, poultry, tofu, yogurt, nuts, or seeds, and vary your choices throughout the week.
Get calcium from dairy or fortified alternatives.
Get calcium from dairy foods such as milk, yogurt, and cheese, or choose fortified alternatives like plant-based milk and yogurt. Check nutrition labels, since calcium levels vary by product, and include calcium-rich foods regularly as part of a balanced diet.
Choose healthy fats from nuts, seeds, and fish.
Choose healthy fats from foods such as nuts, seeds, and fish. These fats provide energy and help your body absorb certain vitamins. Add a small handful of nuts or seeds to a meal, or enjoy fish as part of a balanced eating pattern.
Drink water and limit sugary beverages.
Drink water throughout the day to help your body stay hydrated, and choose it instead of sugary beverages like soda, sweetened tea, and energy drinks. These drinks can add a lot of sugar without providing the same hydration benefits as water. For more flavor, try adding slices of fruit, cucumber, or fresh herbs to your water.