Have you ever had near-fatal sticker shock when browsing for low-growing plants at your local big-box store? Grab a spare pair of clean pants and check out this home improvement chain's catalog page for lobelia. Thirty-five bucks for a four-pack!
Now, go to the bathroom and change. We'll wait for you here. Just wash your hands, please.
OK, you're back. Four lobelia plants just isn't enough, and more than six bucks a plant is way too much. Especially when you can easily grow them at home with a surplus to gift to friends and neighbors, or to sell for a reasonable price at your local farmer's market.
Another benefit to growing your own lobelia is knowing that they've been properly cared for since the get-go. While they're not cantankerous, it's important that they never dry out...and we've seen some parched plants at some of these stores. Even if they're revived, they tend to do poorly when they're finally brought home.
But we hope we had you at "six bucks."
Native Range, History, and Medicinal Uses
Lobelia are members of the Lobelioideae sub-family of the larger Campanulaceae (bellflower) clan.
The genus Lobelia was named for the late 16th century Flemish botanist Matthias Lobel, who tended to King James I as his private physician. Plant nerds have classified more than 400 Lobelia species, with about 43 species being native to the United States, Canada, and Hawaii. The Lobelia genus' native roots also include Asia, Africa, and Europe. Cascade lobelia (L. erinus var. pendula) hails from South Africa, most likely the regions closer to the coastline.
Lobelia foliage contains the compounds lobelamine and lobeline. These compounds are similar to nicotine and can cause in humans cardiac problems, vomiting, tremors and paralysis if ingested. (Arizona State University)
Most references to medicinal lobelia don't apply to L. erinus subspecies, but just for fun, let's take a look at a North American native, L. inflata. It's commonly (and charmingly) known as Indian tobacco, pukeweed, gag-root, and asthma weed, and at one point Native Americans and early European settlers used it as a tobacco substitute, respiratory aid, and hangover cure.
As a young man, the 19th-century botanist, controversial herbalist, and prankster extraordinaire Samuel Thompson used to persuade boys to eat L. inflata. Hilarity would then ensue as the hapless kids would succumb to projectile vomiting. Thompson is widely credited for the species' medicinal use, though according to A Modern Herbal, New England settlers and Penobscot native culture used lobelia for a wide range of treatments long before he came along, only a few of which might have inspired this scene in the classic film, Stand By Me.
Another type of New World lobelia, L. siphilitica (and perhaps also L. cardinalis), had a reputation as a treatment for syphilis. In the earlier part of this century, researchers studied the plant's foremost medicinal compound lobeline as a potential aid to treating methamphetamine addicts. Gives a whole new meaning to party drug, doesn't it?
We haven't found reliable verification that lobelia species such as those we carry have any medicinal properties, but to be safe, don't smoke it, don't eat it, and don't feed it to neighborhood kids. If you need to ease the jones on your meth or nicotine habit, see your doctor. If you're hungover, well, congratulations! You're part of the Seed Needs Gardening and Social Club!
Lobelia in the Garden
Did you know that the most recognizable lobelia species are considered dwarfs? Lobelia are amazingly diverse, with some resembling upright weeds and others actually being trees or large shrubs. We're focusing on the smaller, most versatile types, which are popular for containers, edging, rock gardens and short-season "filler" ground covers. Lobelia is an annual in USDA Hardiness Zones 2 through 9, and it's considered winter-hardy in zones 10 and 11. In some areas with mild winters and hot summers, they're actually used as a winter annual as long as the temperatures don't drop below 40°F.
Lobelia will reseed themselves if you let them, but they're not invasive due to their demand for rich, loose, consistently moist soil. Prepare your lobelia beds by working aged compost into the top six inches of soil. For potted plants, add Perlite and peat moss to prevent soil compaction. Loose, well-drained soil is paramount to lobelia's root health.
It's a fantastic container plant, adding visual interest to multi-species living arrangements. Cascade lobelia, for example, trails over the sides of your containers, helping to break up the outline of pots and raised beds. When things heat up, you can move them into light shade. Be sure to never let your container-grown lobelia dry out. Bottom-watering is the theme for these plants, and it's a good idea to dunk hanging baskets or pots in a pan of water to ensure the roots can soak up the moisture. You can also gently water mature plants at surface level.
Flowers and foliage
Lobelia foliage ranges from bright to dark green, sometimes with a purple or bronze tinge on their tiny, half-inch lanceolate to oval leaves which alternate along the stems. The flowers emerge in clusters at the end of each branch; pinching young lobelia will encourage more branching, denser flowers, and less "leggy" plants.
Ever see those electric blue flowers in the groundcover section of your local nursery? Those are just one of several Lobelia erinus var. pendula colors, which include indigo, lilac, purple, red, and white. Often, the color bleeds to white and then yellow in the centers.
Someone who skipped over the history section might assume "lobelia" is a reference to the shape of the flower. Individual flowers appear to have three rounded petals above, and a deeply-lobed petal below so it's an honest mistake.
The basics of ornamental lobelia cultivation:
- Sunlight Preferences: Full sun to partial shade; the latter is preferred in the afternoon.
- pH Preferences: Lobelia prefers rich, well-drained soil with a pH between 5.5 and 6.2 (slightly acidic).
- Plant Height: 6" to 10" high.
- Plant Width: 10" to 12" wide, but can trail over raised garden edging or hanging containers by as much as 18".
- Growth Habit: Clumping, mounding, trailing, spreading.
- Bloom Period: Late spring through mid-summer; longer in cool, maritime climates.
- Days to Maturity: 14 to 16 weeks after germination.
Lobelia is deer-resistant, and not particularly prone to insect or invertebrate pests. Overly humid, wet conditions or poorly-drained soil can cause stem rot, root rot, and damping off. If the flowering begins to taper off, cut back lobelia to about one third its size. This will keep the plant tidy, and encourage regrowth and bloom when the weather begins to cool late summer or early fall.
Growing Lobelia from Seed
Given that lobelia prefers the coolness of spring and early summer, we encourage you to give them a head start indoors 6 to 8 weeks prior to your last frost. Lobelia plants are easy to start indoors, given that you provide them with appropriate heat, artificial light, and moisture. The starts also transplant well once they reach about three inches tall.
We recommend using nursery flats or cell trays filled with a sterile, loose seedling soil amended with peat moss. Be sure you have a grooved tray to go underneath, as we recommend watering them from below. If you do water on the surface, use a hand sprayer on a gentle mist setting. Watch out for fungus or green moss on the surface of the seedling mix.
Of course, you can direct-sow your lobelia seeds outside, though due to their nearly microscopic size, it's all too easy for them to get buried under the topsoil. Since they need loose, fluffy bedding, you'll need to plant twice as many seeds to ensure that plenty of them receive sufficient sunlight to germinate. Plant them outdoors as soon as your last spring frost has passed, and again after peak summer heat if you live in warm-winter climates and want year-round blooms.
- Seed Treatment: None required.
- Seed Depth: Surface sow only.
- Seed Spacing: Thin, plant, or transplant 6" to 8" apart.
- Days to Germination: 7 to 14 days at 65°F to 70°F.
- Transplanting Tips: Plant lobelia "plugs" in a checkerboard pattern for best bedding coverage.
Use a fine sand and seed mix in a shaker to distribute mass-planted outdoor seeds, and in any situation, gently press the seeds into the topsoil. An old-fashioned #10 pencil eraser will do nicely, but we've actually used the smooth bottom of casserole dishes to ensure the seeds have good soil contact. Just an idea; you might come up with your own. When growing lobelia from seed, keep your lobelias consistently moist throughout their life cycle.
Contact Seed Needs
We'll add to our lobelia collection, but for now, we're proud to offer our multi-colored Cascade mixture. We also take requests to keep the hits coming, and we're always here if you have any questions or need help troubleshooting an issue. In the meantime, bookmark our gardening blog to get some inspiration and tips for planning and growing your successful ornamental, herb, or veggie garden.
By the way, we only offer the freshest, highest-quality seeds available. This is especially important for tiny lobelia seeds. While GMO isn't an issue with ornamentals, our customers count on us to supply them with open-pollinated or traditionally-hybridized plant varieties. We also source our seeds from producers who follow environmentally and socially sound practices.
Your garden should make you feel good about the environment you create, and part of that satisfaction is knowing you're making ethical choices when you shop for your garden seeds. You're also supporting a small family business committed to customer support, and we promise you...for the most part, we don't keep our kids chained to packing tables. At least, not outside of the early Spring rush, so get your orders in early!