Water hyacinth requires about 6 hours of direct and continuous sunlight daily. These are desirable to help them grow healthily, and this will help them grow faster. You might also want to provide these species with supplemental light during the winter with the help of lamps. The species need several hours of unobstructed sunlight to have vibrant foliage, so you might want to place them in the brightest areas of your garden or indoor nursery.

They are suited to a full sun and don't tend to tolerate shady areas. It's best to have at least 8 inches of space for each plant especially if you’re planting a lot of them so each can get a lot of sunlight. Generally, the Water hyacinth has a high demand for direct, full, and abundant sunlight. During summers, you can place them outside in the morning sun, so they will have enough light to grow. They don't do well with partial sunlight and don't tolerate filtered or part shade. They might also not grow well when a huge tree constantly provides shade, so plant them in areas without obstruction.

The Water hyacinth should never avoid sun exposure because they seek and love the bright light. They love the sun so much that they require at least 6 hours of exposure regardless of the climate. Some areas, especially during the fall and spring, don't need protection because they require full sunlight. However, if you're located in a tropical climate or if the summer sun is too much, it's always possible to transfer the potted species inside until the temperature cools down again. Overall, you don't need to plant them near buildings, tall trees, and other structures because they need full sun for at least 6 hours.

If there's insufficient light, the Water hyacinth will not thrive. This is going to result in poor growth. Fungi and bacteria can feed on the plants' tissues, which are generally common for the plants grown in shady areas. When the plants receive too little sunlight, they tend to become spindly. They will have weaker stems because they are constantly seeking to receive light, and this can result in wilting or brown leaves. You might want to see if there are insects present or a rhizome rot in Water hyacinth as this can be another sign that they are not receiving enough sunlight. If this is the case, put them in another area where they will receive bright and direct light to see if it will make a difference.

During their growing phase, you need to expose the plants to the sun so that they don't have to stretch and grow upwards. You can avoid the process of etiolation and prevent the stems of Water hyacinth from growing weak. This is generally prevalent for those that are receiving no sun or are in a partially shaded area when they are young. When they are already established and have matured, you also need to continuously expose them to a full sun because they need photosynthesis to grow more. When they are placed inside a greenhouse or a nursery for a very long time, and you decide to transfer them into a garden, you need to gradually introduce them to the bright lights. Still, you should never suddenly place them in direct heat, especially if it's mid-afternoon. They need a period to adapt and to become used to the intensity of sunlight in your area, so give them some much-needed time.

As mentioned, the Water hyacinth needs 6 to 7 hours of direct sunlight to do the process of photosynthesis. This helps them produce enough food to grow. You can make this easier for yourself when you group them together and plant them in the same spot in your garden. This way, they will get enough of their light requirements to produce flowers, grow sturdy stems, and produce the glucose that they need for their food.

As mentioned, the Water hyacinth loves the sun, but sometimes too much can hurt it. However, too much harsh sunlight can actually burn the leaves in the summer. When planted in the ground, you might want to add to their watering schedule so they will have protection. Exposure to the blades can result in sunburn, especially when the day's sun is too strong. It's highly recommended to spray some water to cool down the leaves a bit.

You need to minimize transplanting shock, especially for the young and newly-planted Water hyacinth. These species will need time to adjust to their new environment but make sure to choose a location where they will get the full sunlight they need. The amount of sunlight matters as well as the season. Water them during the hottest days to reduce stress, and you might want to cover the young ones when the temperatures are extremely high. Row covers and shade cloths might be applicable for the younger ones, but the mature plants might not need them, especially if they already have established roots and stems. When you see that the Water hyacinth begins to lose its color, this might be because it is not receiving enough sunlight to do photosynthesis. There's not enough chlorophyll to depict a green color; if this is the case, you need to transfer it to an area receiving bright sunlight.

For this tropical plant to thrive, you’ll want to keep them between 75℉ and 90℉ (25-32℃). Each species can handle temperatures outside of this range, but keeping it within several degrees of these limits will ensure they grow to their maximum potential. As for its extreme temperature limits, any environment below 50℉ (10℃) or above 95℉ (35℃) will begin to hinder its growth and cause various aberrations to its leaves and stems. This is especially true with low temperatures; even a light frost can cause your tropical plants to perish. Cellular death can begin to happen at a rapid pace, with some species dying in as little as 12 to 24 hours.

While Water hyacinth doesn’t require any changes in temperature to enter different growing phases, it is important to stay consistent. Wild temperature fluctuations can slow down its growth regardless of its current phase, so it's always better to keep them in a controlled environment. That optimal temperature range of 75℉ and 90℉ (25-32℃) is vital to maintain, especially staying above the lower limit. Going above 90℉(32℃) isn’t ideal, but as tropical plant it won’t suffer too much. On the other hand, going below 50℉ (10℃) (and especially 40℉/5℃) will begin to directly damage this heat-loving plant species.

Water hyacinth does not need different temperatures for different growing seasons. The most important step in seasonal care is to keep the environment within the optimal temperature range. That's why it's always best to keep this plant indoors. That way, you can control the temperature no matter what the climate is like outside. Light is also important for tropical species, with all of these plants preferring a partial side level of sun exposure. This means any light they receive needs to be dappled or filtered, with bright but indirect light being the best option when growing your plants indoors. Too much direct sunlight can negatively affect your plant’s leaves, reducing its growth potential.

Tip #1: Don’t Leave Your Plant Near Windows in Colder Months If you want to make sure your plant isn’t exposed to colder temperatures, you may want to keep them away from windows. In colder months like late fall and winter, even the smallest draft can leak cold air into your home through cracks in your windows. While this air usually dissipates and warms up as it travels throughout your home, any plants placed in close proximity to the window will be affected. Move your tropical plants into an area where they will still get bright but indirect light, while making sure they won’t be affected by potential drafts. Tip #2: If You Find Dry Patches, Your Plant May Be Getting Too Much Sunlight or Heat You may notice the leaves become white or even scorched on a sunny day. These discolorations and unusual markings usually indicate that a plant is getting too much heat or sunlight, and it may be dehydrated. Excess light and heat will dry out the soil, stopping plants from getting the moisture they need to support their cellular structure. It also slows down or stops the process of photosynthesis, further hindering growth. If ignored for too long, these dry spots can spread and eventually result in the death of your plants. Tip #3: Avoid Frost at All Costs Colder temperatures and frost can damage your plants by causing ice crystals or disrupt normal physiological activity. This makes it nearly impossible for water to move freely throughout plant tissue, creating a deficit of moisture in their stems and leaves. You can tell a plant has been damaged by frost if it begins to suffer from hydrosis (it will appear as though it's soaked with water.) If the problem persists, your plants may begin shriveling and turning a dark brown or black hue. After that, the plant will almost certainly die.

The best way to maintain the right temperature range for Water hyacinth is by keeping an eye on both the climate and humidity. You’ll want to try to keep each species in a room where you have access to climate control, keeping the heat in the temperature range best mimics its natural habitat. The humidity levels will also have a direct effect on temperature, so it's important to monitor these as well. You can artificially raise the humidity of your growing space by using a humidifier or lightly misting the leaves with water. If you intend to grow this species outside, you may find it difficult to maintain the right balance of temperature and humidity. If temperatures begin to drop or the air becomes too dry, your best option is to find room within your home and move your plant inside. An indoor growing space will allow you to control the climate more closely, helping your plant reach its full potential.