How to Grow the Most Nutrient-Dense Vegetables

The immediate problem isn’t too much water, but rather too little air – the water has displaced the air. When you maintain or improve the structure of your soil by adding organic matter, not working wet soil, and avoiding compaction caused by excessive foot or vehicle traffic and tillage, you’ll also preserve the framework of pores throughout the soil web that deliver water and air to plants.

The Soil Web

Members of the soil web need air, too! Within a plant’s rhizosphere (the soil closest to the roots) are fungi, bacteria, and other microbes. Through symbiotic relationships, plants offer their photosynthetically produced sugars as root exudates to these microbes, which in turn make minerals and moisture more available to plants through their “enormous” surface areas and also encourage the growth of plant root hairs.

Establishing this biological system within your soil can, for example, involve inoculations with compost tea, mycorrhizal fungi, indigenous microorganisms, “effective” microbes, or sea minerals. But, perhaps more importantly, you must support the biological system’s healthy persistence. Protect the soil from weathering and temperature extremes by adding mulch and planting soil-improving crops.

Mineral Musts

The communication that exists between plants and the soil web allows microbes to do a precise job in delivering to plants the minerals they need. But these minerals still need to be in the soil first to be made available and to eventually arrive in your food. Plants require macronutrients (nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur) and various micronutrients or trace elements, including boron, manganese, copper, zinc, and selenium.

A mineral’s designation as a macronutrient or a micronutrient refers to the quantity of it required rather than its importance, as each mineral serves a particular function. For example, both potassium and copper are needed for structural plant development. These minerals have a common purpose, but one won’t perform the exact function of the other; a shortage of any particular mineral will become a limiting factor to optimum growth. Though there are specific soil amendments for each nutrient, you can add granitic and basaltic rock minerals for broad-spectrum re-mineralization at an economical price. Healthy soils develop from the slow weathering of rocks. Adding crushed rock to your garden speeds up that process and brings soils to a healthier state. Sea minerals are another option.

Highly Cultured

Many practices result in more nutritionally dense food from the garden, several of which we’ve already touched on. Mulches prevent moisture evaporation and foster a healthy soil web. Green manures and cover crops add organic matter and root exudates to the soil, and some will specifically sequester nitrogen from the atmosphere and mine minerals from lower soil levels. Minimizing tillage helps to preserve soil structure and foster microbial colonies.

There are other steps to take. Depending on the specifics, companion plants can be used to obtain minerals, sequester carbon, and improve soil tilth (the soil’s physical condition and structure), among other benefits, enhancing both the soil and subsequent crops. Additionally, managing sunlight exposure is important. In extreme conditions, plants may need protection from the sun to avoid fainting and sunburn. However, sunlight not only fuels the production of photosynthates (the plant sugars produced by photosynthesis) but also of phytonutrients that are protective to plants and nutritious to you. Avoid overprotection from the sun, or you’ll sacrifice nutrition.

Grow This, Not That

If nutrition is your aim, some crops certainly deserve more emphasis in the garden. The onion family is a nutritious one, so scallions, shallots, chives, leeks, garlic, and globe onions should all be given their place. Raise your own greens, such as spinach, Swiss chard, radicchio, kale, and mustard greens, to name a few. Small fruits, such as strawberries, raspberries, and blueberries, deserve space when possible, as do winter squash, sweet potatoes, tomatoes, peppers, beets, and carrots. Conversely, cucumbers, summer squash and zucchini, green beans, peas, and melons have comparatively little nutrition. Though they’ll have some nutrition (essentially all fresh produce has some degree of vitamin C, for example) and fiber, these plants just don’t accumulate nutrition to the levels that the crops mentioned earlier do – it’s just not their way!

Superior Sorts

Focus your gardening efforts not only on specific crops but also on particular varieties. Those more nutritious than their counterparts will be more colorful and smaller and have an open structure. Darker colors indicate the presence of bionutrients, such as anthocyanins, carotenes, and lycopene. In general, purples and reds will have more bionutrients than greens and oranges, which are more nutritious than yellows and whites (though with any color, the darker the better). This is true of tomatoes, potatoes, bell peppers, sweet potatoes, globe onions, cabbage, carrots, lettuce, you name it. As with any rule, there are exceptions to it, though, such as globe artichokes, white peaches, and white nectarines.

Since sunlight triggers phytochemical production, which means better nutrition, opt for loose-leaf or leaf lettuce as opposed to tight-headed varieties, for example. Additionally, the skins of produce have higher concentrations of fiber than their softer interiors. For both these reasons, small-fruited tomatoes, peppers, and eggplants are all preferable to their larger counterparts.

Note: You may see specific cultivars described as having extraordinary nutrition, such as ‘Jersey Knight’ asparagus and ‘Packman’ broccoli. This is the inherent genetic potential of the cultivar. By providing the best growing conditions, you’ll allow produce to fully achieve its genetic potential.

Handle with Care

Not only are many fruits and vegetables at peak flavor when fully ripe, but peak nutrition as well. So, pick “fruiting” produce, such as strawberries, blackberries, peppers, tomatoes, winter squash, and melons, when it’s as ripe as possible.

Post-harvest handling is just as important as timely harvesting. Don’t leave harvested vegetables sitting in the sun; the heat will deteriorate their quality. Additionally, the leafy tops on beets, carrots, and radishes accelerate the breakdown of root nutrition and structure when left on. Remove them and store the ones desired for eating separately in a perforated plastic, wax, or linen bag in the fridge.

Storage conditions that maintain produce appearance often maintain nutrition as well. When those are cool conditions (as with lettuce, cucumbers, asparagus, leeks, and radishes), cool your produce as soon as possible, even to the point of picking it early in the morning while it’s still chilled from nighttime temperatures. Clean and thoroughly dry tender produce before storage, especially for extended periods, since moisture is almost as detrimental to good storage as dirt. Still, washing produce can accelerate the cooling-off process; just dry thoroughly before storage.

Timelines

Some vegetables were designed for storage. These are chiefly roots, including beets, carrots, radishes, rutabagas, turnips, potatoes, and sweet potatoes, but cabbages, cauliflower, and winter squash also store well and maintain their nutrition while doing so. However, other vegetables, including asparagus, broccoli, Brussels sprouts, and spinach, lose a great deal of their nutrition in storage. These vegetables are most nutritious when fresh, so keep them on an accelerated path from field to fork.

When fruits and vegetables are intended for canning and freezing, process them after harvest as rapidly as possible, so they better retain their nutrients.

Food Fixing

The final step of bringing nutrition to your plate is food preparation, for which there are a number of points to bear in mind. Consume the nutrient-dense skin of produce whenever possible – from apples to potatoes to tomatoes to the edible skin of winter squash. Some foods offer their top nutrition when consumed raw, such as arugula. However, many benefit from light cooking, as heat makes certain nutrients, such as lycopene and carotenoids, more bioavailable (accessible for absorption in your body). Boiling is a notoriously poor method of cooking vegetables, and it’s especially detrimental to asparagus, beets, and carrots. Avoid it whenever possible. Lastly, include a touch of fat with your vegetables when it’s the fat-soluble vitamins (A, D, E, and K) that you most hope to gain from them.

Leah Smith is a freelance writer and home and market gardener. She works on her family’s mid-Michigan farm, called Nodding Thistle Farm (Certified Organic 1984 to 2009, principally by Organic Growers of Michigan). A graduate of Michigan State University, she can be reached at NoddingThistle@Gmail.com.

Originally published in the June/July 2025 issue of MOTHER EARTH NEWS and regularly vetted for accuracy.