Maximizing garden space often means cultivating the right selection of plants based on the unique physical conditions of each tillable area. One of the biggest challenges to healthy plant growth is maintaining the perfect amount of moisture in the soil. Some gardens naturally have great drainage, whereas others tend to accumulate water. The great news is there are many beneficial plants with a penchant for having “wet feet.”
While many gardeners opt to grow trees and hardy shrubs in permanently waterlogged zones of the garden, the list of water-loving plants is not limited to woody species. Many herbs, including edible greens and fruiting plants, can grow beautifully in consistently moist to wet soil. These plants have adaptations that protect their root and shoot cells from prolonged exposure to moisture.
If you’ve been wanting to grow a vegetable garden but have been hesitant to start due to poor soil conditions, look into the species listed below. These greens should easily take root and become well-established in moist, soggy, or permanently wet conditions. While producing edible plant material for your kitchen, they should also aid in improving the aeration and stability of problematic substrates!
1) Water spinach (Ipomoea aquatica)
This water-loving vegetable is commonly known as kang kong, river spinach, and water morning glory. It favors moderately mild to warm climates with temperatures that rarely dip to below 20˚C (68˚F). As hinted by its common name, it thrives best in fully waterlogged soils and can easily survive in a few inches of standing water. It is thus commercially cultivated in wetland systems and with irrigation ditches.
Because this species grows in moist locations, particularly those where other herbs may struggle to become established, it does have the tendency to become a noxious weed. If you intend to grow water spinach in your rain garden or around water features, restrict its growth to within a limited area. Note that if wild animals regularly move through your property, they may disperse the seeds of this plant.
Despite its capacity to be invasive, this vegetable continues to be cultivated across warm regions of the globe because of its culinary uses and medicinal value. Its tender shoots and leaves are rich in essential nutrients, vitamins, minerals, and dietary fibers. Moreover, its roots can aid in wastewater filtration and help reduce erosion rates along the banks of ponds, streams, and lakes.
2) Water mint (Mentha aquatica)
Often used as a wild vegetable, water mint is a fantastic herb to grow around water features and in permanently moist parts of the garden. In the wild, its stands thrive along the banks of streams and on the shorelines of ponds. A flowering perennial, it can tolerate mild floods and persist in a few inches of water as an emergent plant.
Water mint favors mildly acidic and peaty substrates, through which they naturally spread via rhizomatous growth. In favorable conditions, they can quickly produce well-rooted colonies with fibrous root systems. These aid in improving the stability of shorelines and increasing oxygen flow into the soil. Arising from the roots are purplish green shoots that can grow as tall as 35 inches (90 cm).
As a member of the mint family (Lamiaceae), this species is, of course, known for its minty smell and taste. Apart from having culinary and medicinal uses, its fragrant oils can aid in keeping pests and grazers away from vulnerable parts of the garden. Its blooms attract many pollinators and beneficial insects.
3) Asparagus (Asparagus officinalis)
Known for the palatability and strong flavor of its young shoots, asparagus is a perennial herb. When its stems are left to grow into their mature forms, it is distinguished by needle-like cladodes (specialized stem segments). As they age, the shoots can become increasingly woody and have ornamental appeal. Once established, they produce harvestable spears each spring.
A robust and hardy plant, asparagus can be cultivated in cool regions experiencing lengthy winters. Its roots are adventitious and tend to grow in a bundled manner. Collectively, its root system is referred to as the “crown” of the plant. When exposed to optimal conditions, beds with mature crowns may be productive for decades.
Asparagus can be cultivated in a wide range of soil types. Compared to most tender vegetables, its roots have a higher tolerance for wet and acidic substrates. It is unlikely to survive in permanently wet conditions, but its mature crowns can easily tolerate temporary exposure to excess moisture. While this may not be the most ideal vegetable for the pond margin, it may be suitable for the borders of your rain garden.
4) Cabbage (Brassica oleracea var. capitata)
Cabbage is widely cultivated for its highly nutritious and leafy heads. To produce these within just a few months of growth, it requires adequate levels of nitrogen, phosphorus, and potassium in regularly moistened soil. A lack of nutrients and moisture may cause the leaves to develop abnormally and increase their susceptibility to pests.
This vegetable’s tolerance for occasionally wet soil makes it a good option for lowland gardens that are located in riverine areas. It can also be cultivated close to water features or wherever the soil becomes naturally moist for some time. Best growth, however, is observed in substrates with proper drainage. While constant moisture is a must all throughout the growth season, stagnant conditions can lead to root and leaf damage.
Cabbage comes in many attractive cultivars, with some being more demanding of water and nutrients than others. This species also comes in ornamental varieties (i.e. flowering cabbage) that produce smaller whorls of colorful leaves instead of spherical heads. In areas that are prone to collecting moisture, full sun exposure and ventilation should help prevent damage to the leaves.
5) Taro (Colocasia esculenta)
Now naturalized in many tropical to subtropical parts of the world, taro is popular as an ornamental plant and as a source of edible corms. Largely cultivated as a root crop, it has been commercially grown for centuries. Its heavy water requirements make it suitable for growth in periodically flooded areas. In areas where rainfall levels or general water abundance is low, frequent irrigation is necessary for good growth.
Taro corms grow quickly in swampy and nutrient-rich substrates. In as little as a few months, healthy specimens may be ready for harvest. Usually grown in paddies, taro tends to be most productive when its crown is kept submerged in steadily circulating and moderately cool water. Fully stagnant and markedly warm water conditions may cause the corms to rot.
Taro fields may look quite impressive due to their lengthy petioles and enormous foliage. As this species is a member of the Araceae family, its leaves sprout directly from underground rhizomes. Thus, the only visible parts of the plant throughout the growth period are its lengthy petioles, leaves, and specialized inflorescence structures (i.e. a spadix protected by a spathe).
6) Arugula (Eruca vesicaria)
An extremely popular addition to leafy salads, arugula is an annual herb with highly nutritious foliage. Its multi-lobed leaves, which are known for their strong smell and pleasantly bitter taste, are packed with vitamins and minerals. Its flowers, seed pods, and seeds are edible and rich in nutrients as well. Compared to other leafy greens, mature specimens of this species are more likely to tolerate excess moisture in well-draining substrates.
Arugula generally favors moist environments. It can thrive in dry substrates but will require daily irrigation to produce favorably-sized leaves. Specimens planted in porous pots with drainage holes may need to be watered every morning. Those rooted directly into the ground will benefit from a steady supply of clean and fresh water.
As this species has a shallow root system, it prefers frequent irrigation instead of permanently soggy substrates. Ideally, its soil should be watered as soon as the top layer is dry. Apart from causing stunted growth, an inadequate water supply can damage the flavor of the leaves. Note that even short periods of drought will cause arugula roots to die back.
7) Celery (Apium graveolens)
Commercially cultivated for its crunchy and thick stalks, celery typically grows as a marshland plant. Its roots can tolerate wet and slightly salty substrates, particularly those which are rich in nutrients. This species naturally grows close to clean bodies of moving water. Without the constant supply of moisture, its stalks are prone to becoming hollow, tough, stringy, or small and stunted.
Due to its heavy water and nutrient requirements, celery can be quite challenging for beginner gardeners to cultivate. While it does require a degree of soil drainage, the key to its healthy growth is ample moisture retention and full sun exposure. As the root system of this species tends to be quite shallow, fertilizer applied directly onto the soil’s surface should aid in hastening growth rates.
Usually grown as an annual, celery may take as much as 4 – 5 months to reach favorable sizes. It is considered a long-season crop, with seeds that must be started and transplanted about 10 – 12 weeks before the first spring or fall frosts. If you’re determined to maximize your naturally moist garden, this is one vegetable that’s definitely worth the time and patience!
8) Watercress (Nasturtium officinale)
Farmed as far back as ancient times, watercress is a semi-aquatic vegetable that can be planted along the shallow margins of both slow and fast-moving freshwater systems. It may naturally grow as a wild herb or weed in streams and other types of running waterways, where its presence may denote pristine conditions.
This perennial has adaptations made for thriving in water. Its stems, which are hollow, naturally float and help the plant retain an upright orientation. Though its leaves can survive when they are fully submerged, its stems tend to become more elongated as the plant attempts to access more sunlight in deeper areas. In gardens, a moving water feature with shallow margins is thus the best site for watercress cultivation.
For easy maintenance and rapid harvesting, it would be best to restrict the growth of watercress to submerged pots or buckets. This should likewise help simulate conditions in streams, where water naturally flows around the shoots.
If you intend to grow this plant outside of a water feature, make sure to keep its roots submerged under at least 2 – 3 inches (5 – 7.6 cm) of water throughout the growth period. Any standing water must be switched out about 3 times per week.
9) Cauliflower (Brassica oleracea var. botrytis)
For a vegetable with such widespread demand, cauliflower was domesticated fairly recently. Like broccoli, only its curd-like heads have commercial value. The heads are actually a juvenile form of the cauliflower’s inflorescence. They tend to remain white as a set of outer leaves shield them from the sun and hinder the production of chlorophyll.
Cauliflower favors moist and well-draining substrates with a rich nutrient profile. The highest productivity rates usually occur in locations with full sun exposure and ample ventilation. This annual crop favors alkaline and cool soil. The frequent provision of moisture and supplementary mulch may be necessary to prevent its roots from becoming stressed and dying back.
Due to its sensitivity to changes in temperature and moisture levels, cauliflower can be quite challenging to cultivate. If you intend to grow this vegetable close to water features, make sure that the substrate around each head receives an even supply of moisture. Consider using a drip irrigation system if the soil drains too quickly. Keep in mind that, while this plant does like consistent moisture, its substrate bed should not be waterlogged.
10) Common garden pea (Pisum sativum var. sativum)
The plant that revealed some of the most important facts on heredity and genetics, the garden pea is surprisingly straightforward to cultivate. Known best for its shelled peas or seeds, this species is grown for its pod-shaped vegetables. Depending on the cultivar, its seed capsules can be consumed whole or must be split open to reveal their edible green to yellow peas. Capsules of the sativum variety are fibrous and cannot be eaten.
A hardy annual plant that grows to about 1.5 feet (46 cm) tall, the common garden pea thrives best in rich, moisture-retentive substrates. Provide young plants with a trellis or a stake to aid in their upright and uniform growth. Healthy seeds may germinate in waterlogged substrates with neutral conditions, but a fair percentage may also be lost to rot (especially in cool temperatures).
In optimal conditions, the common garden pea may produce harvestable pods in as little as 50 – 70 days. The best growth rates are usually observed in spring or fall, when temperatures are mild. To encourage the production of more flowers and pods, make use of a fertilizer that is low in nitrogen but high in potassium and phosphorus. If the soil is kept moist, you should have plump peas for your kitchen in no time!
