Platycodon grandiflorus, commonly called Balloon flowers, are herbaceous perennials that grow in a wide range of climates. The beautifully hued flower buds resemble a balloon just before they burst open in late spring. The flowers last for weeks during the early summer. These medium-sized plants can be used as facer plants in front of taller shrubs and perennials or as edging plants to define a mixed garden border.
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Balloon flowers grow well in average garden soil with a neutral pH. Short periods of drought are no challenge for well-established plants, although consistent watering will support large flowers and healthy foliage. An annual top-dressing with organic compost or a slow-release fertilizer is all this easy-going ornamental needs to maintain its vigor from year to year.
Balloon flowers come in a wide range of blue shades, saturated and deep to a pale, almost white perfect for combining with other pastel shades in a garden border or kitchen garden full of raised beds. Balloon flowers have a large tap root, making them difficult to divide and transplant, although Platycodon does readily self-seed and the small seedlings can be moved to other areas before they are established.
Shrubs To Plant With Balloon Flowers
Medium-height balloon flowers make for a nice facer plant to taller shrubs with bare lower stems, including rose of Sharon, viburnum, ninebark, hydrangea, or snowberry. Any shrub that grows well in full to partial sun could be considered a good companion. Other good deciduous shrubs to consider are the early blooming lilac, mock orange, privet, spirea, and deutzia. The blue and purple shades of balloon flowers provide ongoing color long after the spring-blooming shrubs have become a solid green backdrop to the garden border.
Photo by K M, unmodified, Flickr, copyright CC BY 2.0 DEED
Perennials To Plant With Balloon Flowers
Perennials are fun to combine for lots of color and texture from early spring to late fall. Use balloon flowers either to contrast hot summer perennials or to blend in with relaxing and sedate shadier plantings of hostas, ferns, brunnera, and hellebores. For sunny borders, plant balloon flowers with coneflowers, veronica, and lamb’s ear for late-season color, or grow them in partial sun with Japanese forest grass and coral bells. Several groundcovers including sweet woodruff, wild ginger, bugleweed, and creeping Jenny are vigorous enough to compete with the self-seeding of balloon flowers while adding texture and colorful contrast.
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Annuals To Plant With Balloon Flowers
Balloon flowers attract native and non-native pollinators, benefiting veggie and kitchen gardens. Growing these perennials near squashes, cucumbers, beans, peas, tomatoes, and peppers will help to improve crop yields while adding lovely form and color to the space. Other kitchen garden annuals like calendula, marigolds, cosmos, zinnia, and dahlias demand the same growing conditions as balloon flowers and make wonderful cut flowers for arranging and drying.
Best Companion Plants For Balloon Flowers in Containers
Plant up containers of balloon flowers to decorate sunny or partially shaded areas on a deck or patio. Combine balloon flowers with other long-blooming annuals in pastel shades to create a calm and relaxed atmosphere. The cool blues and purples of balloon flowers also make for a lovely contrast to hot and primary flower hues.
Pair balloon flowers with classic spillers such as petunias, pansies, calibrachoa, trailing verbena, and sweet potato vine. Choose filler plants with frothy bunches of flowers, like sweet alyssum, lobelia, coral bells, or angelonia, which contrast the strong shape of the balloon flowers. Regular watering is a must to keep all the plants flowering continuously throughout the summer and early fall.
Plants Not To Grow With Balloon Flowers
Balloon flowers are extremely versatile and can be grown alongside any perennial or annual that requires moderate moisture levels and partial to full sun. Balloon flowers also require good drainage, even in the winter when the plant is dormant. Seasonal flooding and boggy garden soil can cause root rot, making balloon flowers incompatible with pond and waterside plants such as cattails, reed grass, or flag iris.
Best Plants To Grow With Balloon Flowers
Balloon flowers grow best in gardens with full-to-part sun exposure, well-draining soil, and medium moisture levels. They have a taproot, which does not like being disturbed by repeated planting and transplanting. Balloon flowers combine easily with other herbaceous perennials to create a long season of continuous blooming and easy maintenance. Grow them with coneflowers, veronica, and lamb’s ear, and use ninebark and viburnum as a contrasting foliage backdrop.
Sources: “Platycodon grandiflorus.” North Carolina Extension Gardener Plant Toolbox. plants.ces.ncsu.edu