If you are looking for a bright and unusual plant for your garden, consider purple lobelia. Its rich, almost magical blue-violet inflorescences resemble bright candles that can enliven any flower bed or pond bank. This plant attracts not only with its beauty, but also with its stately, compact bush shape, which makes it an excellent accent in any composition.
Growing this beauty will not require any extra effort on your part, but it is worth knowing a few subtleties. Purple lobelia loves moisture and sun, so it feels best near water or in a well-watered flower bed. It is quite hardy and, when planted correctly, will delight you with its graphic beauty from mid-summer until the first frost.
In this article, we will explain in simple terms how to choose a place for it, how to water and feed it so that the plant reaches its full potential. You will learn how to avoid common mistakes and achieve lush, long-lasting flowering that will turn your garden into a little piece of magic.
Distribution
In the wild, it grows on the banks of rivers and lakes. It is native to the subtropical regions of Central and North America. It prefers bodies of water with standing water or a slight current. It rises above the water, producing flower stalks with beautiful bright red flowers.
Growing and care
It has won the attention of aquarists with the following qualities:
Easy to care for, grow, and propagate.- Moderate growth, no need to replant often.
- No special requirements for fertilization or soil.
- Goes well with other plants.
- The roots and small leaves are food for shrimp and snails.
An important point in growing the plant in an aquarium: Lobelia has a pronounced stem that strives for light. To get a lush bush, you need timely pinching and proper planting of young shoots in the ground. Without pinching and transplanting, the plant will look less attractive.
Care requirements are as follows:
Lighting and carbon dioxide are much more important for the full development of lobelia than water parameters, temperature, and soil type.
Water parameters for ideal maintenance
Purple lobelia grows in soft or medium-hard water with a pH between 6 and 8. The temperature range is 20-26°C. Requires weekly replacement of part of the water in the aquarium. For this purpose, pre-settled liquid is used.
Lighting requirements
Lobelia needs bright light, at least 0.5 W/l. Daylight hours should be at least 10 hours. If these conditions are met, the lower part of the leaf will take on a beautiful purple-red hue. A lack of light is accompanied by active yellowing of the leaf plate, which leads to rotting. The front and side plans are used for planting.
Due to its lighting requirements, lobelia is usually planted using the “Leiden street” technique, when individual cuttings of the plant are formed into bushes and planted in the ground diagonally from the front wall to the back. This creates a beautiful transition, and the plant receives the necessary amount of light),
Purple lobelia is a bright and unpretentious plant that is perfect for decorating flower beds, borders, and hanging pots. It loves the sun or light partial shade, needs regular watering, but cannot tolerate stagnant water. The plant grows well in fertile, well-drained soil and blooms profusely from June until the first frost. To keep the bush lush and blooming, you can trim it slightly from time to time. Even a beginner can cope with growing lobelia—the main thing is to provide a little attention and basic care.
Soil requirements
Lobelia roots are poorly developed. Fine-grained soil is preferred. Accessory roots form on the stem where there are no leaves. Cuttings can be easily detached from the stem and buried in the soil nearby. The plant has no supernatural requirements for soil. It takes root well in stones, sand, or artificial filler.
Artificial filler (glass)
Fertilizers and features of their application
Macronutrients: nitrates and phosphates (NO3 and PO4 from which the plant absorbs nitrogen and phosphorus, necessary for full development and good vegetation. After carbon, these elements are key in feeding Lobelia.
Microfertilizers: other components that are freely available in tap water (magnesium, iron, potassium). With frequent water changes, it makes no sense to add micronutrients.
Moreover, an excess of such elements provokes active algae growth, which is a more serious problem than sluggish plants.
Aquarium lobelia should be fed according to the instructions on the fertilizer. If there are signs of problems (wilting, yellowing, leaf rot), then fertilizer should be applied based on the deficiencies.
Before using fertilizers, carefully read the instructions and calculate the correct dose, first determining the concentration of carbon dioxide, nitrates, and phosphates using tests. Balance is important in an aquarium, and the lack of it cannot be corrected with a “magic pill.”
Propagation
Lobelia in an aquarium can be propagated in three ways:
- Cut off the side rosettes with rhizomes from the mother stem – suitable if the young bush has sufficiently formed roots and developed leaf plates.
- Pinching off the top – performed when the stem reaches 20-25 cm. Cut with scissors, then bury the stem with young shoots horizontally. After 10-15 days, the remains of the stem will completely rot, and the young plants will take root. They can be planted or formed into dense bushes.
- Division of the old stem – an old plant with many young shoots with small roots is cut into strips so that each section has 5-6 rosettes with young bushes. The rhizome and the lower hollow part should be removed, and the resulting segments should be buried in the soil so that the roots are completely covered. After a while, the young bushes will separate from the rest of the stem and will be ready for planting in the desired order.
Types
The most common are:
Cardinal lobelia (or blood-red)
Purple dwarf lobelia
A few words from the experts
No matter how simple the process of growing purple lobelia in an aquarium may be, difficulties arise. And they are not at all related to a lack of plant fertilization or improper pruning, but to a lack of knowledge. Let's take a look at the key points.
Temperature and light
A series of experiments has shown that the shape of the lobelia leaf and the number of side branches depend on the water temperature. At low temperatures (19-22°C), the leaf blade is more rounded and the internodes are larger. If the temperature approaches 25°C and above, the leaves become more twisted and elongated. The stem also lengthens and thickens. The most advantageous option for an aquarium is small, squat bushes.
If lobelia does not have enough light, it will inevitably stretch towards its source. The result is a tall, long stem with a minimum of side shoots. If there is enough light and the daylight hours are around 10 hours, the lower part of the leaf will “reward” you with a rich purple-red color.
If you don't cut off the top…
The stem will become thinner and shoot upward, reaching for the air. The plant will cease to be bushy, and its appearance will become less attractive. Lobelia will spend all its energy on feeding and supporting the above-ground part. The side shoots will be sparse and scanty.
The top can and should be removed. It can be planted to get new bushes, or used to replace an old plant by removing its stem along with the rhizome.
Fertilizers: more is better?
Lobelia is not a plant that suffers from acute deficiencies of macro- and microelements. It will react primarily to a lack of light and carbon dioxide, rather than a lack of nutrients in the soil.
The principle of “the best is the enemy of the good” applies here. Fertilizer should only be applied when absolutely necessary, which is determined by testing.
Nothing will happen if the bushes are left without feeding. Their vegetation will slow down, which is convenient for the aquarium owner (no need to spend time on transplanting and pruning). But what do people usually do when lobelia starts to rot and turn yellow? That's right, they pour fertilizer, put nutrient tablets in the soil, and most often do both at the same time.
What is the result? The plant rots faster, and new problems appear in the aquarium (algae, pathogens) that would not have occurred if the aquarium owner had understood that lobelia is the most important thing.
Reproduction
Where does the upper part of the plant usually go? It is discarded. But there is a way to increase green mass and waste-free pruning, which will help grow new lobelia bushes without any hassle.
Here is the sequence of actions:
Examine the selected plant and pinch off anything taller than 20 cm.- Take the stem and cut it into separate strips with scissors, each of which should have a side shoot with aerial roots.
- Place the stem horizontally in the soil, spread the roots, and sprinkle lightly with soil. If you are unsure of success, you can place a root system growth stimulator under the root, but in practice this is not necessary.
- After 20-30 days, the remains of the stem will rot naturally, giving us new young bushes with beautiful stocky leaves.
- You can freely form the planting, choosing any convenient pattern. But nothing better than the “Leiden street” pattern has been invented for lobelia yet.
Lobelia is not a finicky plant, but you shouldn't just let it grow on its own. Timely pruning and proper planting will help decorate any aquarium.
As you can see, growing purple lobelia is not that difficult. The main thing is to remember its love of the sun, regular watering, and light, nutritious soil. Timely pinching and removal of wilted flowers will help you get a lush, flowering bush that will delight the eye until the cold weather arrives.
This plant is a real find for the garden. Its bright, rich candles will add depth to any flower bed and attract butterflies and bees. Lobelia looks great in group plantings and as an accent among more subdued greenery.
Don't be afraid to experiment with it. Even if something goes wrong in the first season, you will gain experience. And when it bursts into purple flames in the summer, you will realize that all your efforts to care for it were worth it.
