Tropical whiteweed (Ageratum conyzoides) Flower, Leaf, Care, Uses

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Tropical whiteweed

Ageratum conyzoides

Also known as: Whiteweed, Bluetop, Floss flower, Flossflower

Tropical whiteweed (Ageratum conyzoides) has a very shallow root system, making it capable of growing in thin and rocky soils along just as well as deep and fertile soil. Their seeds have tiny hairs attached to passing wildlife, allowing them to be spread far and wide. The genus name of this plant, Ageratums, means "non-aging" in Greek and refers to its robust growth and long life.

Late winter, Spring, Early fall

Planting Time

More Info

Flower Color

White

Purple

Pink

Lavender

Bloom Time

Late spring, Summer, Early fall, Mid fall

Leaf Color

Green

Scientific Classification

Phylum

Vascular plants

Class

Dicotyledons

Order

Asters bellflowers fanflowers and allies

Family

Daisy

Genus

Whiteweed

Species

Tropical whiteweed

Weed Control

Weeds

Tropical whiteweed is considered an invasive species in its nonnative areas like Africa, Australia, and some Pacific islands. Tropical whiteweed is a common weed found among agricultural crops in these regions, where it interferes with the growth of the crops and causes ecological and economic damage. This species is also considered a plant disease host vector, meaning it carries plant diseases that spread to other nearby species including agricultural crops. It spreads rapidly by producing between 5,000 and 95,000 seeds per plant. These seeds spread by wind, water, and attaching to animals, cars, and people.

How to Control it

The spread of tropical whiteweed can be limited by regularly removing new growth. Being a relatively shallow-rooted species, unwanted plants are easily eradicated. Even well-established plants can be removed by hand-pulling. Since it reproduces by seed, it's important to remove the plant before it produces flowers. Preventing the tropical whiteweed from setting seeds is the best prevention measure. The seeds are also unable to germinate in low-light conditions. Infested areas that are larger can be mechanically controlled by conventional tillage implements. If none of this works, the weed can be controlled by herbicide, which should be applied before flowering when the plant is actively growing. A wide array of chemicals may be effective active ingredients in the herbicide, including bentazon, butachlor, paraquat, glyphosate, and simazine.

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Distribution Map

Habitat

Cultivated ground

Native

Cultivated

Invasive

Potentially invasive

Exotic

No species reported

Questions About Tropical whiteweed

Sunlight

Temperature

How much sunlight should Tropical whiteweed get per day to grow healthily?

You must expose the plants to at least 6 to 8 hours of sunlight daily. They prefer more exposure to the morning light, especially in the summer. The Tropical whiteweed needs full sun and more sunlight that it can get. The more light these species get, the more they can manufacture food, produce beautiful blooms, and survive.

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What type of sunlight does Tropical whiteweed need?

The Tropical whiteweed grows best under full sunlight. It's best not to crowd them together so they can get exposure to the sun evenly. The leaves shouldn't be starved with sunlight. If planted in pots, try to expose the herbaceous flowers in windows with direct sun and ensure they receive full sunlight regardless of the months.

They don't tend to do well in partial or filtered light as this will not produce strong stems and healthy flowers. It's best if the Tropical whiteweed is always exposed to the sun.

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Can sunlight hurt plants? How to protect Tropical whiteweed from sun and heat damage?

When the temperature rises above 90℉(32℃), the Tropical whiteweed can get damaged by extreme temperatures, especially if they are exposed to many hours of sun. It's always ideal for providing some shade from the light in the afternoon in the summer. It's always important to keep in mind that the sunlight in the summer is stronger than the one in the winter. Sunlight exposure is also 50% longer in the summer than in the winter.

If the Tropical whiteweed is too stressed with sunlight, you might want to keep them fully hydrated. Water them when the top of the soil is about 2 inches dry, and move the plants indoors if it's too hot outside. This is the case if they are planted in containers.

It can be normal for the plant leaves to wilt during the day. Generally, they can recover at night. However, when you notice that the Tropical whiteweed is still drooping, this means that the plant is losing water fast, and you need to water them.

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Should I protect Tropical whiteweed from sun exposure?

The Tropical whiteweed does not need any protection from the sun. In fact, they love the sun, and some species are heliotropic. Plant them in south-facing gardens whenever possible so they can be exposed from morning to afternoon. While the sun can benefit them, some may experience a sunburn. You might offer protection from the afternoon and midday sun through a shade of a tree or a wall.

Growing the Tropical whiteweed in shady areas is impossible because the larger flowers would require a lot of energy to grow and produce. Always provide the lighting conditions and set them in an area with full sun for best results.

What will happen if Tropical whiteweed gets inadequate sunlight?

When the Tropical whiteweed does not get adequate sunlight, or they are not placed in full sun locations, it's worth noting that the photosynthetic process will slow down. A lack of sunlight will cause the stems to become more leggy since they become thin and long since they tend to seek too much sunlight. They will not bloom and produce seeds in the shade.

Inadequate sunlight will also mean that the older leaves can die, the color of the new ones is lighter than the old foliage, and the new growth is smaller than the last ones.

The Tropical whiteweed indeed loves the sun so much. However, they can wilt when exposed to excessive heat and ultraviolet light during the extreme summer months, so be careful. You might want to cover them with a net that has a green shade, especially in the summer, to prevent the leaves and the flowers from scorching. When they are indoors, reduce the heat with the help of a fan.

Does Tropical whiteweed need special care about sunlight during its different growth stages?

When the Tropical whiteweed is growing, they need more light than their mature counterparts. The younger ones should receive adequate light, but they might not be prepared for sudden full sunlight, especially if they are grown in a nursery. They can be more sensitive to the summer sun, so the lighting should be gradual and slow.

How much light does Tropical whiteweed need for photosynthesis?

During summer or late spring, the Tropical whiteweed needs 6 to 8 hours of direct light every single day. This is whether they are planted outdoors. If the Tropical whiteweed is planted in pots or you're growing them in the winter, they need direct fluorescent lights that help them grow better. Make sure to place them in an indoor area where they are facing south or east so they can have enough sunlight for photosynthesis.

Are there any cautions or tips for sunlight and Tropical whiteweed?

When transplanting the plants, they should not be exposed to sudden sunlight. Give the Tropical whiteweed to grow and mature before transplanting outside. Some species of herbaceous plants can grow taller and might cast a shade on other young plants. Allow between 80 to 100 days of growing season before planting another batch to ensure that every plant receives more than enough sunlight for at least 6 hours a day.

Make sure that the Tropical whiteweed receives the best light possible, especially if it's planted in a nursery. These are sun-loving plants, but too much sunlight with a very hot temperature is also detrimental to their growth. Indoor lights should be replaced with natural sunlight as much as possible since these species crave this every day.

What is the optimal temperature for Tropical whiteweed?

Colder temperatures can affect plants since they have the same temperature as the air around them. When they are exposed to the sun, they can start to get warm again, but this is not the case during winter. The temperature range for the Tropical whiteweed is often 70~85℉(21~30℃). They might tolerate 20~30℉(-6~0℃) even 15℉(-10℃), but not for long since this can result in frost damage. Maximum temperatures should be around 70~85℉(21~30℃), but make sure that you spray them with water from time to time and give them some shade to prevent wilting.

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Should I adjust the temperature for Tropical whiteweed during different growing phases?

Do some research and make sure that the temperature is right when growing Tropical whiteweed. Some growers might consider decreasing the plants' thermostats during the growing season to reduce HVAC costs. However, it's vital to understand that the temperature can affect the flowering, pest management, and quality of the plants.

There will be a temperature point where the Tropical whiteweed will stop growing, and this can happen during the winter when some species might go into a dormant state. The base temperature becomes warmer when the season changes and the Tropical whiteweed can grow faster. The species that are naturally growing in warm habitats have higher optimum temperatures when you compare them to the ones that thrive in a cooler climate.

When the seeds of Tropical whiteweed are exposed to cool temperatures, this can cause a decrease in uniformity and delays. You might also want to lower the temperature during flowering but not at other phases. Cooler temperatures at night will also require less water, so adjust the irrigation as needed.

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How can I keep Tropical whiteweed warm in cold seasons?

Stop fertilizing the plant to avoid new growth and allow the old ones to become hardy. This way, they can endure colder temperature when it begins to drop. To keep them warm, you can build structures around the Tropical whiteweed like cages or trellises. There are also options to use heat mats that can gently warm the soil since they can consistently maintain an ideal temperature range for the Tropical whiteweed.

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How can I save Tropical whiteweed from temperature damage?

During winter, you can protect the Tropical whiteweed from frost by covering it with cloths, tarps, burlaps, sheets, or plastic buckets. Make sure to keep them down so they continue to act as insulators and the wind will not blow them away. However, ensure that the plastic sheets or burlap covers should not touch any part of the fruit or foliage, or the cold temperatures can transfer to the material and cause burns. When the temperatures begin to rise during the daytime, remove the covers.

Should I adjust the temperature for Tropical whiteweed in different seasons?

When growing the Tropical whiteweed in spring, you might want to increase humidity since the air temperature tends to be cooler at this time. A dry temperature can be a stressful growing environment for various species, which can help. If summer arrives, the large cover of the greenhouse and the warm temperature will mean that there will be a higher humidity level in the air. Some signs to look for are the condensation that is often found on the walls of the greenhouse, and this can cause issues with pollination and the development of infections when the water begins to fall on the leaves. Make adjustments according to the temperature and do some spraying during the hotter days of the year.

What damage will Tropical whiteweed suffer if the temperature is too high/low?

Generally, the first cold snap can destroy the Tropical whiteweed and others might go into a dormant state when the temperature is low. Some plants can get chilled when the temperatures range from 20~30℉(-6~0℃). They can freeze when the temperature begins to drop below 32℉(0℃). Those species that hide most of their parts under the soil might lose their structures above ground, but they can recover in spring. Some of the associated issues with too low temperatures are the lack of availability of resources like water, and nutrients, and those subtropical plants can suffer when the temperature reaches below 20℉(-6℃). The plants can also get damaged because of extreme heat stress when it's too high. This can reduce the transpiration rate that can affect the growth and productivity of Tropical whiteweed.

What tips and cautions should I keep in mind when it comes to temperature for Tropical whiteweed?

You need to cover the plants at night since these can add about 5 degrees more to protect the species from frost and freezing temperatures. The cloth rows can work well as blankets and ensure that there are no openings where the heat could escape.

When using the covers, avoid the plastic from touching the foliage because this can cause the Tropical whiteweed to freeze. Remember to keep the covers during the day and stop using heat pads during the summer. It will always be worth the effort to protect the cold-intolerant plants from freezing temperatures to help them survive.

How can I keep Tropical whiteweed warm without a heat pad?

If you prefer not to use a heat pad, bring the Tropical whiteweed inside, especially if it's freezing outdoors. During spring, consider the ones you need to bring indoors and plant them in moveable pots and containers.

How can I provide Tropical whiteweed with an adequate temperature condition?

Most often, the ones caring for the Tropical whiteweed will grow them in greenhouses. This is because they can provide adequate temperature in these areas that won't affect the photosynthesis process of a specific process.

Some install the proper HVAC systems to control the temperatures of Tropical whiteweed. This can handle many species' cooling and heating needs, especially during the summer and winter. They generally place the cooling or heating pad under the plants rather than above to achieve their desired temperatures.

If outdoors, you can protect the Tropical whiteweed from frost by covering it with cloths, tarps, burlaps, sheets, or plastic buckets.

Under what conditions should I stop adjusting the temperature for Tropical whiteweed?

Heat mats are often left on Tropical whiteweed to set the temperatures at a more consistent level. When the weather becomes warmer during the day, you can remove them, especially if the species are exposed to the sun. Put the pads away once the plants are established and when they start growing flowers and fruits.

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Add to My Garden

Tropical whiteweed

Ageratum conyzoides

Also known as: Whiteweed, Bluetop, Floss flower, Flossflower

Late winter, Spring, Early fall

Planting Time