Updated at: 15-05-2022 - By: Sienna Lewis

How To Keep Lobelia Blooming All Summer: Beginner’s Guide

Pruning lobelia

Keeping your lobelia plants blooming all summer long requires only one practice, as previously said. In addition to improving the health and look of your plants, pruning lobelia is a good idea. In addition to promoting blooming, this approach also serves to lengthen this period.

Pruning lobelias is a broad phrase that encompasses a variety of techniques. Among these techniques are pinching, trimming, and snipping. You’ll use these strategies at different times, and you’ll have a specific goal in mind when you do so. You can trim your lobelia plants at any time of the year to extend the blooming season or stimulate a second bloom.

How to Grow and Care for Lobelia - BBC Gardeners World Magazine

When the blooming period is complete, some gardeners will even cut the plant by half an inch to encourage another round of blooms and keep the overall appearance in check. Deadheading may be necessary depending on the type of lobelia plant you have. It’s important to keep in mind that some lobelias clean themselves, so you don’t have to remove the faded blossoms.

Caring For Lobelia To Help With Blooming

While pruning the plants is the simplest way to keep lobelia blooming throughout summer, the plant’s general care will ensure that the flowering season will be extended. Remember that no matter what kind of plant you have, proper care and maintenance can have a big impact on its blooming. If the weather in your region is unpredictable, you may want to consider using a greenhouse to cultivate your plants.

Ideal environment

If your lobelias are annual or perennial, the best place to plant them will be different. While annual lobelias flourish best in zones 1 to 10, they can also grow in zones 2 to 10. There are certain lobelias that thrive in full sun or partial shade, while others like a dappled light.

For the most part, lobelias prefer a temperature of roughly 70 degrees Fahrenheit. A greenhouse can be used to customize the atmosphere for your plants and aid in blossoming. Also, don’t forget that lobelias’ health and flowering are influenced by how they are maintained.

Watering and fertilizing

For example, the dry and heat circumstances of summer will necessitate more frequent watering of lobelias. Keep an eye on the medium they employ, especially if it’s in a container. Feeding annual lobelias will help them bloom throughout the season.

Every two to three weeks during the growing season, gardeners recommend applying a 12-4-8 liquid fertilizer. By doing this, you’re ensuring that your plants have the energy they need to develop healthy blooms. As part of routine maintenance, some people apply a general-purpose fertilizer every four weeks or once a month.

Problems to look out for

Preparation and prevention are surefire ways to ensure a season’s worth of blooming goes off without a hitch. One of the most prevalent causes of lobelias not blooming in the summer is dryness. To avoid this, make sure to give them enough of water and cover the soil with a thick layer of mulch.

You should also keep an eye out for pests like spider mites, which thrive in high humidity during the summer months. Neem oil and cold water can be used to prevent mite infection. If there are any evidence of infestation, remove the affected plants as soon as possible.

Planting Lobelias

By planning ahead, you can have your lobelias bloom in time for summer. In the greenhouse, after the last frost in May or the beginning of June, you can plant bedding lobelias. Early summer is a good time to transplant them after they’ve established themselves.

How To Keep Lobelia Blooming All Summer Long - GFL Outdoors

Even in the fall and early spring, you can plant perennial lobelias in the ground that hasn’t yet froze. If you have access to a greenhouse, you can also plant them at any time of the year.

For best results, place your lant in direct sunlight or partial shade. Locate lobelia in a location with at least five hours of direct sunlight per day. Plants thrive in partial shade. Lobelia prefers morning sun with afternoon shade for the finest part-sun conditions.

Make certain that there is adequate drainage. Lobelia, like many other plants, does not thrive in soil that is too wet. Make sure the planting area has good drainage before you begin planting. Drainage can be improved by adding homemade or bagged compost to the area. Planting in pots and using organic potting soil will help you avoid drainage problems.

Maintain a regular watering schedule. Lobelia requires a steady supply of water in order to thrive. In the absence of rain, water the plants frequently enough to keep the soil moist but not saturated. A 2-inch coating of ground bark or leaf mold can help keep the soil around lobelia continuously moist.

Prune every now and then. Keep lobelia bushy to ensure that it continues to bloom, and this can be done by pinching or pruning it back. After the flowers have faded, cut them back and fresh buds will spring up in their place.

Get it done every month. Feed your lobelia on a regular basis with a blooming plant organic fertilizer. Apply once a month during the spring and early fall months.

Master gardener and garden writer Julie Bawden-Davis has been writing professionally since 1985. Her work has appeared in journals like The American Gardener, Organic Gardening, Wildflower, Better Homes & Gardens, and The Los Angeles Times. The Strawberry Story and Indoor Gardening the Organic Way are among her seven publications. She is also the founder of the website HealthyHouseplants.com.

Should I Prune My Lobelia?

Yes. Plants look and feel better when they are pruned. Flowers are encouraged to bloom for longer periods of time because of this. Lobelia plants benefit from three methods of pruning: removing wasted flowers, pinching, and chopping down.

When to Trim Lobelia

The type of pruning dictates when and how much to prune. In the spring, pinching is a common practice. When new stems are about six inches (15 cm) long, pinch them back. When the lobelia has recovered from transplanting, pinch it. You can prune the plant at any time of the year. After the plants have finished blooming, do the bulk of the pruning or cutting back.

Pruning Edging and Trailing Lobelia

The height of these two small plants is around 6 inches (15 cm). Plant hardiness zones 10 and 11 allow them to survive the winter, although they are typically cultivated as spring annuals because they fade in the summer sun.

How to Grow: Lobelia- Grow Lobelia Flowers and its Care

Early summer, when they’re no longer at their finest, is the ideal time for growers to remove their lobelias from their borders or trailings. Cut them back by half to two-thirds if you opt to keep them in the garden. This means that you don’t have to deadhead lobelias that are used for edging and trailing.


Having a beautiful garden doesn’t have to be limited to spring. Even after other plants have finished flowering, a lobelia-filled garden is always a welcome sight. Pruning lobelias is the most common method for extending their blooming season.

Deadheading can help some plants produce more blooms by encouraging them to develop more flowers. The flowering of lobelias will be guaranteed throughout the summer if they are properly cared for. For lobelias, for example, a greenhouse can provide the optimum growing environment.

Summer flowering and blooming can be encouraged by keeping the plants moist and well-fed. Every two weeks, give the plants plenty of water and a liquid fertilizer. Neem oil and cold water can also be used to keep spider mites at bay during the summer months.