How to Plant and Grow Blue Lobelia

There are few blues more intense and gorgeous than those found on annual lobelia. The mounding type, called edging lobelia, is beautiful for planting in rows in the front of beds and borders. The cascading type is stunning, like a sapphire waterfall, spilling from window boxes or pots. Annual lobelia is in its glory during the cool weather of spring and fall. Except for cool-summer areas, such as the Pacific Northwest or higher altitudes, lobelia stops flowering during the heat of summer. Shear the plant back when this happens, and it will likely rebloom come fall.

Varieties of Blue Lobelia

'Blue Wings' Lobelia

Lobelia tenuior 'Blue Wings' bears large blue flowers on a mounding plant perfect for hanging baskets. It grows 10 inches tall.

'Lucia Dark Blue' Lobelia

Lobelia erinus 'Lucia Dark Blue' offers gorgeous true-blue flowers on a trailing plant that's more heat tolerant than many older varieties. It trails to 24 inches.

'Magadi Blue' Lobelia

Lobelia erinus 'Magadi Blue' offers better heat tolerance than most lobelias. It offers soft-blue flowers and grows 10 inches tall.

'Magadi Blue With White Eye' Lobelia

Lobelia erinus 'Magadi Blue with White Eye' is a sister to 'Magadi Blue' and also has great heat tolerance. It offers soft-blue flowers marked with a white throat. It grows 10 inches tall.

'Riviera Midnight Blue' Lobelia

Lobelia erinus 'Riviera Midnight Blue' bears dark blue flowers and bronze-tinged flowers on vigorous, mounding plants.

'Riviera White' Lobelia

Lobelia erinus 'Riviera White' bears pure-white flowers on vigorous, mounding plants.

'Regatta Rose' Lobelia

Lobelia erinus 'Regatta Rose' bears brilliant carmine-rose flowers with a white center on trailing plants.

'Regatta Sapphire' Blue Lobelia

Lobelia erinus 'Regatta Sapphire' bears clear blue flowers with a white center on trailing plants.

Blue Lobelia Companion Plants

Loosestrife

These vigorous growers are beautiful additions to the garden. They vary from tall, stately plants suitable for borders to others that can be planted as creeping groundcovers. Flowers, too, vary from tight spikes of 1/2 inch to 1-inch cups carried alone or in whorls. Humus-rich, moisture-retentive soil is recommended; some varieties enjoy wet soil and ample water. Several sorts may become invasive and need to be corralled.Note: These are not the invasive purple loosestrife, which has been banned in many parts of the United States.

Firewitch Cheddar Pinks

The quintessential cottage flower, pinks are treasured for their grasslike blue-green foliage and abundant starry flowers, which are often spicily fragrant. Depending on the type of pink, flowers appear in spring or summer and tend to be pink, red, white, rose, or lavender, but come in nearly all shades except true blue. Plants range from tiny creeping groundcovers to 30-inch-tall cut flowers, which are a favorite with florists. Foliage is blue-green.

Pansy

From tiny, cheerful Johnny jump-ups to the stunning 3-inch blooms of Majestic Giant pansies, the genus Viola has a spectacular array of delightful plants for the spring garden. They're must-haves to celebrate the first days of spring since they don't mind cold weather and can even take a little snow and ice! They're pretty planted in masses in the ground, but also cherished for the early color they bring to pots, window boxes, and other containers. By summer, pansies bloom less and their foliage starts to brown. It's at this time that you'll have to be tough and tear them out and replant with warm-season annuals, such as marigolds or petunias. But that's part of their charm—they are an ephemeral celebration of spring!

Garden Plan for Blue Lobelia

Summer Cottage Garden Plan

Stately delphiniums are the backbone of this colorful cottage garden plan.

Click here to get this free garden plan!