Lobelia is an easy to grow annual that is also used as a medicinal herb. The leaves are long, slim and grass-like. It is a low growing flowering plant and most types mature to be about three to five inches tall. The flower typically has about three large petals extending from the lower front and two smaller petals at the top. Blue is the most commonly sold color of lobelia flower but pink, white and purple are also available. Lobelia can grow well in window boxes or hanging baskets and at the fronts of flowerbeds. It has also been used through history to heal various ailments.
Lobelia as a Medicinal Herb
The lobelia plant is sometimes known as Indian tobacco. Native Americans used to smoke it because they believed it eased respiratory ailments like asthma. Europeans also cultivated lobelia for medicine. During the 1800s doctors used it to induce vomiting. Now, the lobelia plant is used in alternative medicine for the same ailments, which is why it is sometimes known as asthma weed. Lobelia must be used in small doses or it can cause side effects such as vomiting or dry mouth. Only use lobelia under the direction of a health care professional.
Types of Lobelia Flower for the Home Garden
While lobelia may be useful in medicine, it is most commonly used as a bedding plant in flower gardens. Lobelia works best as a border or in a rock garden. There are hundreds of different varieties of lobelia. Some types mound, others trail. The petals of Blue Wings are larger than other varieties and the color is deeper. Sapphire is a beautiful trailing plant. Crystal Palace is very compact in habit and commonly sold in garden centers as transplants.
How to Grow Lobelia Flowers from Seed
Lobelia plants are grown from very small seeds. They should be started indoors about ten to twelve weeks before the last frost date in order to ensure blooms for most of the summer. Some gardeners have better germination results if they chill them beforehand. Called stratification this gives the lobelia seeds a cold period that mimics winter dormancy. To do this, add sterile potting soil or soiless mix to a small plastic bag, such as a sandwich bag. Add the seeds to the bag. Place the bag in the refrigerator for about three months.
When it comes time to plant just spread the soil in the bag over the soil in the planting area. If not doing stratification, just lightly scatter the seeds over the top of the soil. Do not cover. Lobelia seedlings need light to germinate and this can take up to two or three weeks. Young lobelia plants are prone to damping off disease if the conditions are too wet. Water the plants from the bottom by adding water to the saucer or tray under the pot or seed tray. This will prevent the seeds from washing away or from getting too much water and rotting.
Though some may enjoy the challenge of starting seeds indoors lobelia is best grown from purchased transplants. When buying the lobelia transplants make sure they are healthy looking. They should be stocky and not wilted or leggy. Plant them outside in the garden after the last frost date. Space them about four to six inches apart.
How to Care for the Lobelia Plant
Lobelia does best in cooler temperatures and moist rich soil. They can grow in either full or part sun. Part shade in the afternoon will help them. Cut them back in midsummer when they stop blooming in the heat. To do this, just cut off the tops of the plants and they will be stimulated to re-bloom once the weather cools down. Generally lobelia does not have many problems with pests and diseases.