
Sometimes tool designers just don’t understand gardeners. They come up with all sorts of devices that look good, but when you try to do anything even faintly gardenesque, they break, prove to be hard to manipulate or they just don’t work. Here’s one more!
Someone somewhere came up with the idea that a watering can that was also a spray bottle would be great for indoor gardeners and created one… and since then all sorts of manufacturers have come out with their own version. You can now find one or more models in just about every garden center as well as on the Internet. Many of them are quite elegant in appearance and they come in really trendy colors too… but what are you expected to do with this tool other than use it as decoration?
No Need to Spray Houseplants
First, the basic concept — that a houseplant lover would need a watering can that could also be used as a sprayer — is just wrong.

This comes from the antiquated concept that misting houseplants with water will increase their atmospheric humidity, and that therefore that, as you’re watering your plants, you could also mist them… but that just doesn’t work. Spraying water on plant leaves does not increase the atmospheric humidity in any appreciable way… and it’s even harmful to plants, leaving white limestone spots on the leaves that reduce its photosynthesis and look horrible. (Read Horticultural Myth: Misting Your Houseplants to find out more about why misting indoor plants is a waste of time.)
Yes, we all need watering cans. We want to keep our houseplants alive, after all. Yes, we all occasionally need sprayers to apply products to our plants, notably pesticides. But I fail to see any occasion when we’d also want to pour the pesticide found in a spray bottle onto the soil of our plants. Watering cans and sprayers contain very different products and really need to be 2 separate things.
Awkward to Handle

Even assuming that you could find a good reason to water a plant and spray it with the same product at the same time: just try to do it with one of these devices. True enough, they do a fairly good job of watering (although they don’t contain much water, ensuring you’ll need to make several trips to the tap!), but just try to operate the sprayer when the watering can is full of water. If you try with one hand, you discover it really wasn’t designed to be held that way: it doesn’t feel right. Plus the weight of the water tends to pull the sprayer downward: it isn’t well balanced. And if you try to hold it with both hands… well, what can I say, it just feels terribly awkward.

Also, as you manipulate the sprayer to mist various plant parts, the spout of the watering can, which sticks way out in front, either punctures a hole in your plant or ends up pointing downwards and — bingo! — you’ve just watered the floor!
Solution
I suggest just doing what you’ve always done: use a dedicated watering can when you need to water and, if you have to spray any kind of product, use a spray bottle, maybe a recycled bottle of cleaning fluid that you rinsed well.

The one good use I can think of for a watering can-sprayer is as a child’s toy. Kids could have lot of fun (outdoors) running around pouring and spraying water.
Haha indeed, this seems silly and must function best as a child’s toy!!