Perennials

Agapanthus: A Guide to Planting, Growing, and Care

Introduction

Agapanthus, a genus of six species of perennial plants, is native to South Africa. Known for their vibrant bell-shaped flowers, these plants add beauty and elegance to any garden. This comprehensive guide will provide you with all the essential information you need to successfully plant, grow, and care for agapanthus.

Botanical Characteristics

Agapanthus features striking flowers that bloom in shades of blue, pink, purple, and white, often with a darker center stripe on each petal. These flowers are borne on tall stalks, while the leaves spread out wide and long from the base. Depending on the variety, the leaves can be evergreen or deciduous, and they range in color from dark to light green, gray-green, or blue-green.

Planting

The ideal time to plant agapanthus depends on your location and the species or hybrid you have. In USDA hardiness zones 9 and 10, plant agapanthus in the ground in autumn. For zones 7 and lower, plant in spring when soil temperatures reach 50 degrees Fahrenheit.

When planting, place the rhizomes (underground stems) two inches deep and 12 to 18 inches apart. The pointed end of the rhizome should face upward. Add a heavy layer of mulch for protection from cold weather.

Growing Requirements

Light: Agapanthus thrives in full sun, requiring six to eight hours of sunlight daily. In hot climates, afternoon shade is beneficial.

Soil: These plants prefer fertile, light, sandy loam with good drainage. Agapanthus africanus prefers slightly acidic soil with a pH between 5.5 to 6.5, while other species grow well in a neutral soil pH of 7.0.

Water: Water regularly to provide 1 inch of water per week until plants are established. Reduce watering to 1/2 inch per week thereafter. Agapanthus are drought resistant but do not tolerate standing water.

Temperature: Ideal temperatures for agapanthus range from 50 to 60 degrees Fahrenheit. Some species can tolerate temperatures as low as 20 degrees Fahrenheit, but many evergreen types should be brought indoors when temperatures reach an average of 50 degrees.

Fertilizer: Fertilize once in spring and again two months later with a balanced fertilizer. Alternatively, use a fertilizer with a higher phosphorus content, such as a 5-10-10 ratio. Avoid over-fertilizing, as this can reduce blooms or cause flower stems to fail to reach their full height.

Types of Agapanthus

There are six main species of agapanthus, all of which hybridize easily. Here are a few popular and common types:

• Agapanthus africanus ‘Arctic Star’: A semi-evergreen early bloomer with large clusters of white flowers.
• Agapanthus africanus ‘Bressingham Blue’: A deciduous type with large flower clusters bearing amethyst blue flowers with a dark blue stripe.
• Agapanthus praecox ssp. orientalis ‘Queen Mum’: An evergreen cultivar with early to mid-summer blooms of white and violet-blue flowers.
• Agapanthus campanulatus var. patens F2 hybrid ‘Brilliant Blue’: A dwarf cultivar with rich blue flowers and a dark purple stripe.

Care

Pruning: Once flowers fade, remove the entire stem to promote repeat blooming. Remove dead or damaged foliage at any time, but avoid cutting back foliage from deciduous types after blooming.

Propagation: Agapanthus is easily propagated by division. Garden-grown plants should be divided every four to six years, while potted plants bloom better when root-bound and should be divided every four to five years.

Overwintering: Evergreen agapanthus should be heavily mulched or grown in pots and moved indoors for overwintering. Deciduous varieties can withstand occasional light frost, but frozen ground can damage the base of the plant. In colder zones, dig up the rhizomes of deciduous varieties in autumn and store them or plant them in pots for the spring.

Common Problems

• Yellowing Leaves: Evergreen varieties may experience yellowing leaves at the end of the growing season. This is a natural process, and the affected leaves can be removed.
• Reduced Blooms: Reduced blooms may indicate that the plants need to be divided. Replant the newest growth and discard older plants from the center of the clump.

Additional Information

How to Grow Agapanthus from Seed:

1. Collect seeds from dry brown pods that mature in late summer or early autumn.
2. Sow seeds immediately, as their viability is short-lived.
3. Fill seed trays with a moistened, well-draining seed starting medium.
4. Soak seeds for several hours before planting.
5. Place seeds on top of the medium and cover lightly.
6. Water lightly and place in a sunny location with temperatures between 68 and 86 degrees Fahrenheit.
7. Keep soil moist but not wet.
8. Transplant seedlings into 12-inch pots or plant out in the garden after the final frost.

How to Pot and Repot Agapanthus:

1. Use a container 12 inches wide with drainage holes.
2. Fill the container with a lightly moistened potting mix and sand or grit for drainage.
3. Plant rhizomes 1 inch deep with the pointed end up.
4. Water lightly and withhold water for several days.
5. Gradually move the plant into a sunnier location.

FAQs

• Is agapanthus a perennial or annual?

Agapanthus is a perennial plant that grows best in mild winters. In colder zones, deciduous varieties can be lifted and stored in autumn and replanted in spring.

• Should agapanthus be cut back?

Remove flower stems after they fade, but retain foliage until deciduous types die back naturally. Remove dead or damaged leaves at any time.

• How does agapanthus spread?

Spread occurs mainly through rhizomes, although it can also reseed.