Definition and Key Characteristics

Herbaceous plants are characterized by their soft and flexible green stems, which contain little to no woody material. These plants typically die back to the ground in the fall, but their underground plant parts, such as fleshy roots, tubers, rhizomes, bulbs, or corms, survive the winter and store food reserves.

Types of Herbaceous Plants

Herbaceous plants can be classified into three main types:

• Annuals: Non-woody plants that complete their life cycle, from germination to seed production and death, within a single growing season.

• Biennials: Non-woody plants that complete their life cycle over two growing seasons. In the first year, they produce vegetative growth, and in the second year, they flower and produce seeds before dying.

• Perennials: Non-woody plants that live for more than two years, often indefinitely. They typically feature flowers and have either woody or non-woody stems. Some herbaceous plants, such as peonies and banana plants, are considered perennials.

Function and Importance

Herbaceous plants play a vital role in ecosystems by:

• Providing food and shelter for wildlife
• Supporting pollinators
• Improving water quality
• Adding visual interest to landscapes with their flowers and foliage

Common Herbaceous Flowers for Landscaping

Many herbaceous plants are popular choices for landscaping due to their attractive flowers and ease of care. Some common examples include:

• Common sneezeweed (Helenium autumnale)
• Daylily (Hemerocallis)
• Starflower (Lysimachia latifolia)
• Hosta (Hosta spp.)
• Catmint (Nepeta)
• Yarrow (Achillea millefolium)
• Peony (Paeonia officinalis)
• Beebalm (Monarda spp.)
• Coral bells (Heuchera spp.)
• Astilbe (Astilbe spp.)
• Russian sage (Salvia yangii)
• Acanthus (Anisacanthus quadrifidus var. wrightii)
• Geranium (Pelargonium spp.)
• Blanket flower (Gaillardia x Grandiflora)
• Coreopsis (Coreopsis spp.)

Sub-Classes of Herbaceous Perennials

Herbaceous perennials can be further classified into sub-classes based on how they store nutrients underground during the winter:

• Bulbs: Underground structures that store nutrients, such as in daffodil flowers (Narcissus).
• Tubers: Swollen underground stems that store nutrients, such as in dahlia flowers.
• Corms: Swollen underground stems with a papery outer covering, such as in the snake lily (Amorphophallus konjac).
• Rhizomes: Underground stems that grow horizontally and store nutrients, such as in the Japanese knotweed (Polygonum cuspidatum).

Other smaller sub-categories of herbaceous plants without flowers include ferns, grasses, sedges, rushes, mosses, and even some carnivorous plants.

Herbaceous Plant Care in Northern Climates

Herbaceous perennials may die back to ground level in the fall, but they often return the next year. Some plants’ above-ground growth remains attractive, despite being dead. If the plants are healthy, you can refrain from cutting them down until spring. Leaving the above-ground vegetation may even provide insulation to help the plant survive winter.

Examples of herbaceous perennials that can be left standing in the winter include:

• Joe-Pye weed (Eupatorium)
• Coneflowers (Echinacea)
• Maiden grass (Miscanthus)

To supplement herbaceous plants in your winter landscape design, consider adding evergreen trees and shrubs, which offer more winter interest.

Frequently Asked Questions

What does herbaceous mean in landscaping?

Herbaceous plants are non-woody plants that die back in the fall but typically return the next year. They add visual interest and sustain themselves during the winter using their underground food storage systems.

What are the characteristics of an herbaceous plant?

Herbaceous plants have soft and green stems that usually die down to the ground every year.

What is the difference between a perennial and a herbaceous plant?

A perennial plant continues to grow for more than two years, while a herbaceous plant has non-woody stems. Some herbaceous plants can be perennials. Essentially, herbaceous refers to the plant’s stem structure, while perennial refers to its lifespan.

Plant Overview

Diascia, also known as twinspur, is a delicate and charming plant native to South Africa. It is a popular choice for containers and hanging baskets due to its compact size and attractive blooms. Diascia is a versatile plant that can be grown as an annual or a short-lived perennial in warmer climates.

Varieties and Characteristics

The genus Diascia comprises approximately 70 species, ranging in size from 6 to 12 inches tall and 18 inches wide. Some popular varieties include:

• Diascia barberae ‘Blackthorn Apricot’: Soft pink flowers
• Diascia ‘Picadilly’: Large white flowers
• Diascia ‘Flirtation Orange’: Soft orange flowers
• Diascia integerrima ‘Coral Canyon’: Salmon-pink flowers
• Diascia personata: A species with pink flowers that can reach up to 4 feet tall

Growing Conditions

Light: Diascia prefers full sun but can tolerate partial shade, especially in hot climates.

Soil: The plant thrives in well-drained, slightly acidic soil with a pH between 6.0 and 6.5.

Water: Diascia requires regular watering, but it is important to avoid overwatering. Allow the top inch of soil to dry out before watering again.

Temperature and Humidity: Diascia prefers cooler temperatures and blooms best in the spring and fall. It is somewhat frost-tolerant and can survive light frosts.

Fertilizer: A slow-release fertilizer applied once a month during the growing season will help promote healthy growth and abundant blooms.

Care and Maintenance

Pruning: Diascia does not require deadheading, but it can be pruned back by half if it becomes leggy or spent. This will encourage new growth and blooming.

Propagating: Diascia can be propagated from cuttings taken in the spring or fall.

Growing from Seed: Diascia seeds are rarely available, but they can be sown indoors 6-8 weeks before the last frost.

Potting and Repotting: Diascia is well-suited for containers. Use a well-draining potting mix and ensure the container has adequate drainage holes. Repotting is generally not necessary.

Overwintering

In USDA zones 9 through 11, diascia can survive the winter as a short-lived perennial. In colder climates, it is grown as an annual and cannot be overwintered.

Common Pests and Diseases

Diascia is generally disease-resistant, but it can be susceptible to pests such as snails and slugs. These pests can be controlled by lifting the plants off the ground or using snail and slug bait.

Troubleshooting Common Problems

• Lack of Blooms: Insufficient sunlight or fertilizer can inhibit blooming. Apply a phosphorus-rich fertilizer to encourage flowering.
• Leggy Growth: Over-fertilizing or insufficient light can lead to leggy plants. Reduce fertilizer frequency and ensure the plant is receiving adequate sunlight.
• Yellowing Leaves: Overwatering or poor drainage can cause yellowing leaves. Allow the soil to dry out before watering again and improve drainage if necessary.

Additional Tips

• Companion Planting: Diascia pairs well with other plants that prefer similar growing conditions, such as lobelia, alyssum, and verbena.
• Attracting Butterflies: Diascia flowers are a magnet for butterflies, making it a great choice for attracting these pollinators to your garden.
• Using as a Spiller: Diascia’s trailing habit makes it an ideal choice for use as a spiller in mixed containers or hanging baskets.

Expertise and Experience

Mary Marlowe Leverette is a highly experienced Master Gardener and orchard owner with both home gardening and commercial farming expertise. She has been a Master Gardener for over 30 years, and has over 50 years of experience in commercial and home gardening. Leverette is also a former Clemson University Extension Agent and has been a member of The Spruce Gardening and Plant Care Review Board since 2021.

As an extension agent with Clemson University, Leverette played a key role in promoting the first Master Gardener programs offered in South Carolina in 1981. She also collaborated with horticulturists in the development of Riverbanks Botanical Garden, which opened in 1995.

Along with her brother, Leverette owns Marlowe Farms Apple Orchards, where she has gained extensive experience in growing vegetables, annuals, and perennials in both home and commercial settings.

Education and Expertise

Leverette holds a Bachelor of Science degree from Mars Hill University and a Master’s degree from the University of South Carolina. She received her Master Gardener training from Clemson University.

Leverette’s expertise encompasses a wide range of gardening topics, including:

• Orchards
• Perennials
• Annuals
• Vegetables
• Commercial crops

The Spruce: A Trusted Resource for Home and Garden Enthusiasts

The Spruce, a Dotdash Meredith brand, is a leading home website that provides practical, real-life tips and inspiration to help people create their best homes. The Spruce reaches over 32 million people each month and is committed to providing trustworthy advice from certified experts for home and garden improvement.

Master Gardener Programs

Master Gardener programs are designed to train volunteers in the science and art of horticulture. Master Gardeners provide research-based information to the public on a wide range of gardening topics. Leverette has been involved in the development and promotion of Master Gardener programs throughout her career.

Riverbanks Botanical Garden

Riverbanks Botanical Garden is a 70-acre botanical garden located in Columbia, South Carolina. The garden features a variety of plant collections, including a rose garden, a Japanese garden, and a children’s garden. Leverette played a key role in the development of the garden and continues to be involved in its educational programs.

Marlowe Farms Apple Orchards

Marlowe Farms Apple Orchards is a family-owned and operated apple orchard located in Columbia, South Carolina. The orchard grows a variety of apple varieties, as well as peaches, plums, and other fruits. Leverette and her brother have over 50 years of experience in commercial fruit production.

Conclusion

Mary Marlowe Leverette is a highly respected and experienced Master Gardener with a wealth of knowledge in both home and commercial gardening. Her expertise and dedication to horticulture have made her a valuable resource for gardeners of all levels.