It is not recommended to water plants at night time. If you have a hectic daytime job then you may only have time to spare for gardening late in the evening.
It is vital to keep up with your irrigation schedule for optimal plant health, and so you can water plants in the evening if you have no other option.
If you are going to water your plants in the evening, I advise taking more care. Try not to get water on the leaves, flowers, or fruits of the plants and focus on just hydrating the roots.
Where possible, try to only water your plants at night if the soil is really dry, to minimize the risk of overwatering.
What are the problems with watering plants at night?
When you water your plants, you are likely doing it from above. This means that the leaves, fruits, and flowers are all being coated in a layer of moisture.
This is not much of an issue during the daytime as the temperatures tend to be warmer and the sun is shining.
This allows the plants to dry off completely in a relatively short time. If you water your plants at night, the moisture sits on the outside surface for much longer. This provides the perfect environment for fungi and bacteria to take root in the plant.
If your plants are suffering from any kind of disease, allowing water to sit on them will further the disease’s progression.
Plants engage in a process known as transpiration, similar to how humans breathe. This is the process of exchanging moisture and gas with the air surrounding the plant. There are small holes in the surface of leaves, known as stomata.
These open and close, allowing water vapor to escape from the plant. This can only happen in the sunlight, meaning that water on the leaves at night remains on and in the plant.
This allows pathogens to make their way into the plant and can cause it to rot.
If your soil is not naturally crumbly, you may notice it becoming waterlogged when you water at night time. This is because compacted soil is very hard for the water to penetrate, meaning that the liquid pools on the surface.
As this sits there, the roots become suffocated as no oxygen can reach them. If the water stays stagnant for a while this can even cause the stems or leaves of your plants to rot.
If the temperature outside is particularly low, such as during the winter months, you may run into even more problems.
Watering at night, when the temperature is lowest, can cause an artificial frost to set in. This can cause premature death of your plants.
You should take even more care when it comes to watering indoor plants at night time. This is because ventilation indoors is worse than outside, so watering at night is a double whammy of problems for your plant.
If you want to increase the ventilation, we recommend switching on a nearby fan or opening a window to facilitate more evaporation.
What is the best time to water plants?
The best time of day to water plants is in the morning. This is because there is a calm breeze and low temperature, but not as low as at night.
The water that is allowed to sit on the surface of the leaves will have plenty of time to dry throughout the day and will help to protect the plants from extreme heat and sunshine.
This gives the water the perfect time to seep into the soil and reach the roots. Not too much water will be lost to evaporation (as it would if you watered at midday) and it will not drown the plant either.
Plants are known to absorb more water during the day, meaning that less water is lost to the soil.
If you are using a hose, watering can, or sprinkler, we advise watering your plants between 5 and 9 am.
The second best time to water your plants is in the afternoon. This is because most of the high heat of the day has passed, but there are still a few hours of sunlight to dry the leaves before the night arrives.
Should you water your plants every day?
There is no one size fits all answer to this question. Like people, not all plants are the same and they will all have different care needs.
We advise looking up your specific plants on the internet or downloading an app such as Planta which advises you on a good watering schedule for each plant.
It is not completely necessary to water your plants daily, despite how tempting this may be. You are likely to want to keep the soil damp by gently watering the surface.
This is actually not the most conducive to plant health as the water will not permeate deeply into the soil.
This means that deep root growth is stunted, and as a result, so is overall plant growth. Water more infrequently, but thoroughly saturate the soil when you do. This will allow water to travel deeper and will encourage stronger, healthier root growth.
As a rule of thumb, give your plants about an inch of water per week, and 2 inches during warmer months.
If you have plants outside in pots, you will need to water them more regularly. This is because the soil will dry out faster – the smaller the pot, the faster the soil will dry. You should soak the soil in the pot every morning.
If the temperature exceeds 90 degrees Fahrenheit then we recommend soaking the soil again in the afternoon.
It is a good idea to use a watering wand to water any plants you have contained within pots. This directs the stream of water near to the soil level with ease. This means that less moisture contacts the foliage, meaning the chance of disease is reduced.