How to Tell If You're Under or Over Watering Your Plants
Watering is a major source of life for all plants, right up there with proper sunlight and soil nutrients. Many people think it’s an easy job, but keeping plants perfectly watered is a bit of an art. While some plants aren’t picky and will tolerate under or over-watering, most species have specific needs that should be followed based on their moisture requirements. Here’s how to tell if you are over or under-watering your plants.
Under-watering usually happens when people have a busy schedule, go on vacation, or don’t understand what a plant’s water needs are. If you are away from home a lot or are still developing your green thumb, look for drought-tolerant plants, or ones that aren’t finicky. Here are some signs that your plant needs a good, long drink!
If you start to see your plants droop or wilt, it usually means they are thirsty. This goes for indoor and outdoor plants, although outdoor gardens will require more diligence with watering, especially on hotter days. You should soak an outdoor pot up to the rim and wait for it to drain out the bottom or allow for garden soil to be completely saturated - and that goes for all plants: a small sprinkle won’t do it.
If a plant prefers dry conditions, you still want to soak it, just less frequently than other plants. Indoor plants don't need to be soaked, but watering should still be thorough. This ensures moisture goes all the way to the roots.
Even if your plants aren’t showing signs of distress, you want to be on top of watering before they start to wilt. Get used to checking the soil in both indoor and outdoor plants, and try to get on a weekly routine. Outdoor beds will retain more moisture as the water soaks deeper into the ground, especially if the beds are mulched properly, while outdoor pots and planters will lose water very quickly on hot summer days.
The general rule for pots is to water when the soil is dry an inch or two at the top. Again, some plants prefer dryer soil than others (succulents, cacti, roses, lavender, orchids). Alternatively, some plants prefer moister soils (majesty palms, astilbe, ferns, creeping fig, zebra plant), in which case you can increase your watering rotation for them.
Discolored or Falling Leaves
If you notice that your plant is losing foliage, looks different in any way, has spots or discoloration of leaves, or is paler in color than normal, you may be under-watering. Discoloration can also mean other things like pests or diseases, but observing changes in the way your plants look is another part of knowing when to water. If you see something is off, first check the soil. If it's dry, the plant most likely needs a drink. If soil conditions are good, this may not be a watering issue.
Lack of Growth
Just like discoloration and other visible signs can be an indicator that you're under-watering, lack of growth in your plant is another tell-tale sign. Some plants aren’t supposed to grow a lot, especially in the winter, so don’t fret without understanding each species’ expected growth rate. Most plants generally put out flowers and start to grow more when spring rolls around, so if you haven’t seen any action by summer, you may be under-watering.
Overzealous plant owners and gardeners can do more harm than good when over-watering their babies. Sometimes less is more, especially in drought-tolerant plants. Here’s how to know when to put the hose away.
Wilt can happen with over-watering and looks similar to plants dying of thirst. You’ll know the difference between the two by checking the soil: if it’s soggy or moist, then you may want to lay off and let things dry out. This can also be a sign of “wet feet,” which commonly happens when your pot does not have any drainage. Most plants can’t tolerate water sitting on the bottom of the pot, as it provokes root rot and will eventually kill them, especially particularly vulnerable species like succulents and cacti. If drying out doesn’t help, you may need to re-pot.
Fungus (and Other Growing Things)
Fungus, algae, mushrooms, or mold on your plant or in the soil can all be signs of over-watering. You may see white or dark spots on leaves or along foliage and stems that aren’t bugs. Certain kinds of soil fungus, algae, and mold can even look plant-like in their own right: look for any weird-looking ground cover that sits on top of the soil, and remove it immediately.
Slime mold and mushrooms are an indicator of wet soil, but they aren't always cause for alarm, and mostly mean that there is a lot of organic material in the soil. A smell can also be an indicator of soil that's too wet. Any sulfurous or moldy odors mean the conditions are ripe for fungus and mold to thrive. Best to change out the soil if you can, or let things dry out before you resume watering. Mixing perlite or peat moss can also help aerate wet soil.
Discolored or Falling Leaves
Again, over-watering can look like under-watering when leaves fall off or change color (yellow, brown, spotted). Many people make the mistake of watering more when they see falling or discolored leaves, thinking that it’s a sign of under-watering. Again, that’s why it’s important to check the soil and know your plant’s requirements: if a jade plant, for instance, is losing its leaves and the soil is wet, put down the watering can and let it completely dry out.
When you start to see changes in your plant, don’t rush to water it, but don’t neglect its cry for help, either. Check the soil, and depending on your plant’s moisture needs, either back off on the watering or give it a nice, long drink.
Make sure every plant is in a pot or container with drainage holes, with a good potting mix that allows for water retention without getting too soggy (this is why garden soil won’t do as potting mix). While you may lose some along the way, don’t let it deter you. Eventually, you’ll get the hang of how to tell if you are over or under-watering your plants.