QUESTION: Will it help my tomato plants if I mist them with a spray bottle? My houseplants love being misted and I want to make sure my tomatoes do their best. — Maria V.
ANSWER: While misting some indoor plants can have benefits for their health, you should not follow the same guidelines with tomato plants or other plants in your outdoor garden. Misting the leaves of these plants would lead to excess moisture, which can cause fungal diseases, rot, and other potentially fatal issues. As a matter of fact, you should even avoid splashing the leaves of your tomato plants when you water them and try not to water them at night.
The best way to water your tomato plants is to water them in the morning or early in the day before the sun gets too high in the sky. If it’s too warm when you water your plants, the sun can heat up the water and scorch your plants’ foliage, causing sunscald. But if you wait too late in the day until the sun goes down and the air is cool, you run the risk of causing fungal diseases due to moisture not evaporating.
The only time when your tomato plants will actually benefit from being misted with a spray bottle is when they are young seedlings. Very young tomato plants dry out very easily and should be monitored carefully and frequently (more often than once a day) to make sure the soil they are growing in stays moist. However, it is very easy to overwater seedlings because their soil is so shallow, so misting them with a spray bottle is a great way to limit the amount of water you give them. Whenever the soil appears to be drying out, you can mist the plants just enough to moisten the top of their soil.
Once tomato plants have matured, they require much more water (between one and one and a half inches of water each week) in order to produce a harvest. As when they were seedlings, with mature tomatoes it is vital to make sure they stay consistently moist. Just be sure not to maintain the misting regimen you used with your tomato plants when they were younger.