9 Best Annual Plants for Moist Soil

For eye-popping color from spring to fall, annuals can’t be beat. But soggy soil can make it tough to keep annuals alive and thriving, especially those prone to root rot and fungus. We’ve compiled a list of the best annuals for moist to wet soil.

If you live in a swampy area, have a ditch in your yard where water pools, or want to build a rain garden, these annuals are the antidote. Most of them naturally grow around rivers, lakes, and bogs, which means they’re well-adapted to waterlogged soil. 

1. Annual forget-me-not (Myosotis sylvatica)

Charming periwinkle flowers with yellow and white centers sure make annual forget-me-nots hard to forget. These lovely low-growing flowers have oblong, bright green leaves and clusters of spring-blooming flowers that attract butterflies, bees, and birds. 

Forget-me-nots are ideal for rain gardens and water gardens, and they grow beautifully around garden borders and as a ground cover. Just be sure to deadhead them (cut fading blooms) to promote new blossoms and prevent excessive self-seeding. Otherwise, you could end up with an army of weedy forget-me-nots next year!

• Plant type: Flowering annual
• Hardiness zones: 3-8
• Sun exposure: Full sun, partial shade
• Mature size: 6-12 inches tall; 6-12 inches wide
• Special features: Pollinator-friendly, deer-resistant, rabbit-resistant

How to plant annual forget-me-not

Start seeds indoors eight to 10 weeks before the final frost date of spring or directly sow seeds outdoors a few weeks before the final frost date. If you live in a warmer climate, spread seeds outdoors in early fall for spring blossoms. 

Forget-me-nots are excellent self-seeders, so you can hold off on reseeding plants for the next year. They also can overwinter as biennials in warmer areas. 

2. Impatiens (Impatiens walleriana)

“Popular” doesn’t begin to describe impatiens. These mounding multicolored beauties are the superstars of cottage gardens, container gardens, hanging baskets, and deeply shaded areas where other plants refuse to grow. Attracting butterflies and hummingbirds galore, impatiens blossom in spring and don’t stop until the first frost of fall. 

Impatiens boast deep green, succulent leaves and orange, red, white, purple, or pink flowers, depending on the cultivar. A special bonus? Impatiens are self-cleaning (they naturally shed spent flowers), which means you won’t have to do any deadheading.

Caution: Impatiens walleriana (AKA busy Lizzie) is highly susceptible to downy mildew, a water mold that causes leaf spots and can lead to defoliation and death. If you’re planting impatiens in a wet area, consider the disease-resistant “Imara” or “Beacon” cultivars.

• Plant type: Flowering annual
• Hardiness zones: 2-11 (grows as a tender perennial that is not winter hardy in zones 10 and 11)
• Sun exposure: Partial shade, full shade
• Mature size: 8-24 inches tall; 10-12 inches wide
• Special features: Pollinator-friendly, long blooming season

How to plant impatiens

Start seeds indoors nine weeks before the last frost date of spring, or directly sow seeds outdoors after all danger of frost has passed. Choose a shaded location protected from the wind. 

3. Fiber optic grass (Isolepis cernua)

Fiber optic grass looks like the bright green head of a mop, and it behaves like one, too! This stunning sedge soaks up standing water and thrives on the shores of rivers, streams, and marshes. Unlike most of the annuals on this list, fiber optic grass isn’t famous for its flowers. Instead, it’s prized for its glossy, hair-like leaves that droop gracefully as it matures. 

You can grow fiber optic grass in the ground, as a houseplant, or in a pond, water garden, or rain garden. If you plant fiber optic grass in the ground, do not let the soil dry out, as this will cause the foliage to turn a sickly shade of brown. 

Caution: Fiber optic grass is toxic to dogs and humans if ingested, so plant it in a location where pups and young kids won’t take a bite of it. 

• Plant type: Grassy sedge
• Hardiness zones: Tender perennial in zones 8-11; annual in zones north of zone 8
• Sun exposure: Prefers full sun, but can tolerate partial shade
• Mature size: 10-12 inches tall; up to 20 inches wide
• Special features: Deer-resistant

How to plant fiber optic grass

Sow fiber optic grass directly into the ground in spring after the danger of frost has passed, raking a light layer of soil over the seeds. If growing fiber optic grass as a container plant, start seeds in a mix of potting soil and peat moss. 

Bring potted plants indoors before the first frost of fall to keep them alive for the next growing season. 

4. Five spot (Nemophila maculata)

Every petal of the five spot is a work of art. These graceful trailing wildflowers boast delicate, bell-shaped white flowers with purple-blue spots at the tip of each petal that resemble a painter’s brushstroke. Five spots are native to California and thrive in cooler climates, blooming all spring long before self-seeding in fall. 

Five spot is a stunning accent for rock gardens, cottage gardens, and container gardens, and around pathways and patios. Plant it in your wildflower meadow to attract bees and butterflies and provide a habitat for native wildlife. 

• Plant type: Flowering annual
• Hardiness zones: 3-10
• Sun exposure: Prefers partial shade, can tolerate full sun
• Mature size: 6-12 inches tall; 8-12 inches wide
• Special features: Pollinator-friendly, long blooming season

How to plant five spot

Directly sow seeds into the soil in early spring when soil temperatures reach 55-65 degrees Fahrenheit. Do not start seeds indoors, as five spots do not transplant well.

Sprinkle seeds over the ground and then rake lightly to mix seeds into the soil. In climates with warmer winters, sow seeds in fall for spring blooms. For best results, plant five spots in an area that gets afternoon shade. 

5. Flower-of-an-hour (Hibiscus trionum)

Flower-of-an-hour gets its name from the creamy hibiscus-like flowers that bloom for only one day each. But don’t fret about losing flowers: Flower-of-an-hour blooms profusely, so you’ll see plenty of beautiful big blossoms from midsummer into early fall. 

This tall, rapid grower forms compact mounds with dark green, lobed leaves. Flower petals are white or yellow with a hint of purple, with deep magenta centers. Flowers bloom on sunny days and stay closed during cloudy weather. Along with its magical flowers, flower-of-an-hour produces unique, inflated seed pods that resemble Chinese paper lanterns.

• Plant type: Flowering annual
• Hardiness zones: 2-11; grows as a tender perennial in zones 10 and 11
• Sun exposure: Full sun
• Mature size: 1-3 feet tall; 1-3 feet wide
• Special features: Pollinator-friendly

How to plant flower-of-an-hour

Sow seeds indoors four to six weeks before the final frost date of spring or outside after the danger of frost has passed.

6. Jewelweed (Impatiens capensis)

Jewelweed will be the shining jewel in your soggy, shady landscape. In fact, it got its name because it appears to sparkle like a gemstone when wet. Also known as the spotted touch-me-not, jewelweed is a self-seeding native plant with bright orange, pouch-like flowers with striking flecks of red inside the throat of the flower. 

Hummingbirds, bumblebees, and butterflies can’t get enough of jewelweed blossoms. Flowers begin blooming in midsummer and continue until the fall frost. For a fun late summer activity, gently touch the seed pods: They’ll dramatically pop open at the slightest touch (hence the name “touch-me-not”).

Fun fact: If you’re feeling itchy, use the sap of the jewelweed to soothe irritated skin, hives, sores, and poison ivy rash. Jewelweed has long been a part of Native American medicine. 

• Plant type: Flowering annual
• Hardiness zones: 2-11 
• Sun exposure: Full sun, partial shade
• Mature size: 2-5 feet tall; 1.5-2.5 feet wide
• Special features: Pollinator-friendly

How to plant jewelweed

Cold stratify jewelweed seeds by sealing dry seeds in a bag and storing the bag in the refrigerator for two to three months before planting. Sow jewelweed seeds outdoors in early spring, or start seeds indoors and transplant them once the threat of frost has passed. 

7. Meadowfoam (Limnanthes douglasii)

With cheerful yellow and white flowers that resemble a poached egg, meadowfoam is a beautiful breakfast for bees. It grows rapidly to form a bushy carpet of yellow-green, fern-like foliage, making it the perfect contrast to dark green, larger-leafed shrubs and perennials. 

Native to California and Oregon, meadowfoam is an excellent self-seeder and resists most diseases and pests. Plus, it attracts hoverflies that prey on pesky aphids, so you can hold off on the pesticide. 

• Plant type: Flowering annual
• Hardiness zones: 2-11
• Sun exposure: Full sun
• Mature size: 6-12 inches tall; 6-12 inches wide
• Special features: Pollinator-friendly

How to plant meadowfoam

For winter and early spring blooms, sow seeds directly into the ground in fall after soil temperatures are below 60 degrees Fahrenheit. If you have harsh, cold winters, plant seeds in early spring for summer blossoms.

8. Monkey flower (Mimulus x hybridus)

With funnel-shaped multicolored flowers and deep green succulent leaves, monkey flowers will transform that bare shady spot beneath your trees or porch from an eyesore to the crown jewel of your yard. These lovely low-growers spread rapidly and are excellent in annual garden beds, hanging baskets, and container gardens, and as border plants for footpaths and patios.

Monkey flowers range in color from white to light pink, orange, and yellow, boasting distinctive crimson spots and patterns. They bloom from late spring or early summer to the fall frost. 

• Plant type: Flowering annual
• Hardiness zones: 3-10; grows as a tender perennial in zones 6-9
• Sun exposure: Full sun, partial shade
• Mature size: 6-12 inches tall; 6-12 inches wide
• Special features: Hummingbird-friendly, edible leaves

How to plant monkey flower

Start seeds indoors 10 weeks before the final frost date of spring, chilling seeds in the refrigerator for 10 to 21 days before taking them out and moving them to a warm location (70 to 75 degrees Fahrenheit). Alternatively, you can spread seeds outdoors in early spring. 

9. Taro (Colocasia esculenta)

If you’ve ever had bubble tea, you’ve probably seen taro on the menu. Also known as elephant’s ear, taro is an eye-catching plant known for its enormous, distinctive leaves that come in a variety of colors and ornate patterns. 

Native to southeastern Asia, taro is technically a tender perennial but is generally grown as an annual in the U.S. It grows exceptionally well in rain gardens and water gardens, around ponds, and as a houseplant.

Caution: All parts of the taro plant are toxic to humans and pets unless cooked first. 

• Plant type: Broadleaf herb
• Hardiness zones: Perennial in 8-11, annual north of zone 8
• Sun exposure: Full sun, partial shade
• Mature size: 3-6 feet tall; 3-6 feet wide
• Special features: Cooked roots are edible and high in vitamins A and C

How to plant taro

Start tubers indoors six to eight weeks before the last frost date of spring. Plant the bulbs outside after the danger of frost has passed, once daytime temperatures are consistently above 70 degrees. Turn the soil to a depth of 8 inches and level it with a rake, removing stones and twigs. Mix compost into the soil at least two weeks before planting. 

Dig holes so that the top of the bulb is 4 inches below the soil line, and fill in the 4-inch hole with soil. Plant bulbs 2 to 4 feet apart.

How to care for your annuals

Here is a general guide to caring for annuals throughout the growing season. Plant needs vary by species and climate, so be sure to check the instructions on your seed packet or planting container, or ask a friendly employee at your local garden center.

• Keep the soil moist for seven to 10 days after planting to promote strong germination.
• Water your annuals daily or every other day, so that the soil doesn’t dry out. Don’t wait to water until plants are wilting. 
• “Harden off” indoor-grown seedlings before planting them outdoors by slowly increasing the amount of time they spend outdoors over a two-week period. 
• Fertilize annuals with a slow-release granular fertilizer or organic fertilizer at the time of planting. Apply a second round of this fertilizer in late June or early July to encourage annuals to keep blooming. 
• Fertilize annuals with a fast-release liquid fertilizer once a week or once every two weeks.
• Trim annuals to prevent legginess and encourage a dense, bushy shape.
• Deadhead annuals daily or every other day during the blooming period unless they are a self-cleaning species.

FAQ about annual plants for moist soil

Add annuals to soggy spots

Whether you’re building a rain garden or water garden, or just have a soggy spot of your yard that can’t easily be fixed, these annuals will stand up to swampy soil and thrive in poorly drained areas. 

While picking out pretty annuals in spring can be one of the best parts of yard care, other lawn chores aren’t always a walk in the park – they can be more like a slog in the mud. Call a local lawn care pro to mow, weed, fertilize, and clean up, so you can relax once your annuals are in the ground. 

Main Photo Credit: Tony Alter | Flickr | CC BY 2.0