If you decide to water your Atlantic white cedar, you will be happy to find that it is a straightforward task. One of the easiest ways to water this tree is by simply turning on your garden hose and using it to soak the soil slowly. Your garden hose is the ideal watering tool to use for mature Atlantic white cedar trees, as large specimens may need a high volume of water during each watering. However, for smaller trees, you may get by by using a watering can or some other smaller watering tool. Also, you should try to avoid overhead watering as excessive moisture on this plant’s leaves can lead to disease, especially when the tree is young.

At times, overwatering can be the result of poor soils. Mainly, if the soil in which your Atlantic white cedar grows does not allow water to drain effectively, the plant will likely begin to decline. If this is the case, you should either amend the soil to improve its drainage characteristics or transplant your Atlantic white cedar to a more favorable growing location. If you grow your Atlantic white cedar in a pot, this can also mean you may need to repot your plant with looser soils in a container that allows for better drainage. An overwatered plant may also contract diseases, which you should try to treat immediately. For an underwatered Atlantic white cedar, the remedy is quite simple. Begin watering more often, and soon your plant will bounce back and return to full health. The easiest way to tell if you have overwatered your Atlantic white cedar is to observe the plant’s foliage. Specifically, looking at the new growth will give the clearest sign of whether this plant suffers from too much moisture. An overwatered Atlantic white cedar may produce new growth, but that new growth may be discolored or prone to easy breakage. Another sign that the soil for your Atlantic white cedar is too moist is if you notice standing water or that water is not draining quickly in your plant’s growing area. Underwatered Atlantic white cedar trees will also have symptoms present in the foliage. In this case, the leaves may become sparse, brown. Usually, Atlantic white cedar can grow well with rainfulls. If you see such symptoms on your plant, you should consider if there has been too much rain recently or constantly high temperatures, which will help you to make the correct judgment.

A mature Atlantic white cedar does not need much water at all. In most instances, this tree will become drought tolerant and survive off of nothing more than rainfall. At most, you’ll need to water this plant about once per week during the hottest months of the year, but during other seasons, you probably won’t need to water it at all. The exception to that rule is if you are dealing with a plant that has been newly planted. If that is the case, you should water regularly to maintain consistent soil moisture and help the roots establish themselves. With that said, the most important thing to remember when watering Atlantic white cedar is that this species does not tolerate standing water. As such, when in doubt, you should err on the side of not watering your Atlantic white cedar rather than risking watering it too much.

The height of summer is one of the few times that you’ll need to water your Atlantic white cedar. At that time of year, it is typical to give this plant about one inch of water per week. However, that amount can change depending on how much it has rained. If it has rained one inch or more that week, you won’t need to give any water to your Atlantic white cedar.newly planted Atlantic white cedar will need more water during the establishment period. Typically, this amounts to watering about once every one to two weeks for the first few growing seasons.

The Atlantic white cedar tree will need the most water during the summer months when the weather is the hottest. At that time, you should give this plant water about once per week in the absence of rainfall. During other times of the year, this plant will often survive with no water at all. In spring and fall, you might need to provide some water if the weather is exceptionally hot, but this is rare. Unlike many other plants, the Atlantic white cedar does not enter full dormancy in winter, which means that it will continue growing, during the coldest months. Still, the water needs during winter will remain quite low as the cool temperatures will not cause the soil to dry out quickly..

Young Atlantic white cedar trees need significantly more water than those that are established. A newly planted tree should receive water at least weekly to ensure that the soil remains moist to facilitate root development. After the first growing season, your Atlantic white cedar should be well-adapted to its new growing location and should need much less water. At this time, you can begin following the standard instructions for watering this species, providing supplemental water about once per week during summer when it does not rain. Beyond that, there is no other time at which you’ll need to alter your watering habits based on the growth stages of the Atlantic white cedar tree.

It is far more common to grow the Atlantic white cedar in an outdoor growing location. However, it is also possible to grow this plant indoors in a container. In that scenario, one gardener often raise the Atlantic white cedar as the bonsai plant. Whether you grow this plant indoors or outdoors, you can expect its water needs to remain relatively similar. The one difference is that you may need to water an indoor Atlantic white cedar tree a bit more. Indoor plants won’t have access to rainfall during the summer. Also, indoor areas are often much drier than outdoor growing locations, and the size of the pots limits the water-retainability, which can lead to higher water needs.

For healthy growth, make sure that Atlantic white cedar receives at least 3–6 hours of sun each day. This is actually a minimum requirement—most plants that can handle part sun can also thrive in full sun, but because they require less light for photosynthesis, they are more flexible than plants that require full sun or part shade.

Atlantic white cedar does best with exposure to full or part sun. They will perform best with direct morning light, but in summer they need protection from the strong afternoon sun. In temperate environments, too much hot afternoon sun can burn the leaves, damaging the plant's appearance and health.

Atlantic white cedar planted indoors can easily be damaged by direct sunlight when it's moved outdoors. The best way to prevent sunburns from overexposure is to move pots gradually from a shaded area to a brighter spot, gradually. But even plants that are acclimated to the summer sun can be damaged by extreme heat. In a heatwave, it is important to keep the soil consistently moist so that plants can cope with excessive levels of heat. Moving plants in containers to areas with afternoon shade or erecting a shade cloth over them can protect sensitive Atlantic white cedar during extreme weather events.

While bright morning sun and some full sun exposure can be highly beneficial for Atlantic white cedar, the harsh, hot midday sun of summer can be too much to handle. If planted in the ground, the summer sun will usually ramp up slowly enough through the season for Atlantic white cedar to gradually adapt to its intensity. But a potted plant that has been indoors or in a protected location will often suffer injury when placed suddenly into a location where the direct summer sun reaches it in the hottest part of the day. To protect this plant from the brutal afternoon summer sun, plant or place it in an understory location where it is shaded at midday by taller trees and plants or by a building or landscape feature.

When Atlantic white cedar receives too little sun, they may become pale green or display drooping, yellow leaves. While some leaf drop is normal, if leaves are dropping but no new ones are growing in to replace them, it is a sign that something is wrong. If Atlantic white cedar receiving inadequate light does manage to grow, the new growth is often spindly, pale, and prone to insect infestation. Paying attention to these signs and changing the lighting conditions of the plant will make a significant difference.

Tender, new leaves are especially sensitive to sunburn. Bearing this in mind, very young Atlantic white cedar and when it's in a strong growth phase, such as in late spring and early summer, will be more sensitive to harsh sun and heat than the mature one or those in a more dormant fall growth stage. Atlantic white cedar fresh from a nursery is also usually not prepared for strong full sunlight and must be introduced to it slowly.

Recently transplanted Atlantic white cedar will often experience a bit of shock and will need to be cared for carefully, either shaded from bright afternoon sun or placed in a protected area. On very hot days, you may see the leaves of Atlantic white cedar drooping—this is usually nothing to worry about. Plants will send the water in their leaves down into their roots to protect them from burning. However, if the leaves are still drooping in the evening or the next morning, the plant needs water. Always avoid watering during the hottest times of day, as sunlight can hit wet leaves and scorch them easily. Atlantic white cedar that has been underwatered will be weaker than that with consistently moist soil. This can leave it with weak roots that are unable to protect the leaves on hot, sunny summer days by diverting water away from the leaves. Care for an underwatered plant by giving it a long, deep watering and then allowing the top two inches of soil to dry out before the next watering. Even if it loses its leaves, if cared for properly it will grow new ones.