When I first got some potted tomato plants they started to wilt a bit from the heat. I thought I probably didn’t water them enough. So, I did some research into when I should water potted tomato plants and put together this helpful article to explain what I found.
You should water potted tomato plants when the top layer of the soil feels dry to the touch. I recommend watering the tomato plants in the morning so the excess water on the foliage will evaporate when the sun comes out. This prevents fungal diseases from infecting the tomato plants.
Knowing exactly when to water them can be tricky, and you can add too much water if you’re not careful, which can drown the roots causing root rot. So, below I will explain how to make sure your potted tomato plants always have the right amount of water, and helpful tips on caring for them.
How often should I water my tomato plants in pots?
You should water your tomato plants in pots anytime the soil becomes overly dry to the touch.
There’s an easy method to know if the potted tomato plants need water. Put your finger 1-2 inches into the potting soil. If the tip of your finger does not feel the moisture, it’s time to water the plant.
You can do this check every morning when you inspect the potted tomato plants in your garden.
When tomatoes fruit, it is a good idea to give them more water. This is because when your tomato plants start to fruit, it uses more water. This extra water is needed to make juicy flavorful tomatoes.
If you water your tomato plants too much it is a waste of water as it will drain out from the pot. Each watering also washes away some nutrients from the soil. So, you should be careful to only water them when they need it.
In hotter seasons and climates you will need to water your tomato plants at least daily. People who live in hotter climates often invest in a drip irrigation system. This saves them a lot of time.
If your potted tomato plants are kept outside and it’s raining, you won’t need to water them at all. In colder climates where there is little sun, you won’t have to water your potted tomato plants as often.
How to reduce the watering your potted tomato plants need?
Organic mulch is material like wood chips, grass clippings, dried leaves, or hay. Mulch decreases how often you need to water the potted plant.
The organic mulch that you put on top of the potting soil insulates it from the heat or cold weather conditions. The mulch also absorbs the water when you water the potting soil and helps retain moisture longer.
When you use organic materials like grass clippings or dried leaves as a mulch they slowly break down and add nutrients to the potting soil.
Use water-retaining crystals
You can add water-retaining crystals to the potting soil when preparing the pot. These crystals absorb water when you water the potting soil.
They slowly release the water back into the potting soil over a period of time. This helps the potting soil retain moisture longer and reduces how often you need to water it.
Use a self-watering container
A self-watering container comes with a pot attached to a reservoir. You don’t directly water the pot but add water to the reservoir.
The tomato plant’s roots will absorb the required moisture from the reservoir using the wicking action.
The benefit of using the self-watering container is that you can fill it up and the plant will continue to use the required amount of water for days.
Another option is to set up a drip-irrigation system that is manual or with a timer. This will slowly drip water into the potting soil and keep it moist based on your settings.
What is the best time to water potted tomato plants?
I think the best time to water potted tomato plants is in the morning before sunrise. This gives the roots to absorb the required moisture from the soil.
If you splash water on the foliage, the sun will come out and dry the excess water. This prevents a humid condition on the leaves that may invite fungal diseases.
You can water the plants in the evening but you will need to be extra careful not to splash water on the leaves. The excess water will stay overnight and cause fungal infections on the plant.
When you water your potted tomato plants on a cold night, the water stays in your soil much longer and causes issues such as root rot.
Can you overwater tomatoes in pots?
Overwatering is one of the most common problems that beginners make when growing tomatoes in a pot.
If you follow the trick that I mentioned on how to know when to water the plant, you will avoid this problem.
If you can see water above your soil for more than a few minutes you have overwatered your tomatoes. The soil has what is called a porosity, meaning the percentage of air or empty space in the soil.
When you water your plant small droplets of water stick to the empty spaces and get slowly absorbed by your plant’s roots. If you overwater the soil, it becomes soggy and the roots can’t function properly as they drown in the water.
The water should pass all the way through the soil and end up in the dish at the bottom, or running out onto the ground. You want the water to pass through and moisten the soil all the way through. But you don’t want the water to pool up in the dish for a long time.
Ideally, the water that comes out the bottom of your potted plant should be a small amount only a quarter of a cup or less. Otherwise, you are using too much water, that leaches nutrients out of the soil unnecessarily.
This makes it vitally important to have drainage holes at the bottom of your potted plants and set them up in such a way that the water can flow out of them easily. You want to avoid the water pooling at the bottom of the pot, which begins to grow mildew and other root problems.
Which water is best for your potted tomato plants?
I would recommend using rainwater for the potted tomato plants. This is the purest form of water with the right minerals for the plant.
The problem is you need to be able to collect the rainwater in a rain barrel and use it as needed.
The next best option is to use distilled water for the potted tomato plants. But this can become expensive when you try to use bottled water. You may need to invest in a distiller at home.
It’s also OK to use tap water for the potted plants. But before you use it, leave the tap water standing in a container for a day. This helps remove the chemicals like chlorine and fluoride that can be harmful to the growth of the tomato plants.
You should water potted tomato plants when the soil becomes too dry. You can tell when your soil is too dry by sticking your finger into it about an inch (2.5 cms). If it feels dry against your skin then you should water them. How often this occurs depends on your climate.
If it’s particularly hot you may need to water them a few times during the day. To cut down on watering time many people use a drip irrigation system.
Make sure you’re not overwatering the potted tomato plants. This is visible when there is a layer of water standing on the surface of the potting soil.