Can we use sprayers to water plants?

Question

I have a colleague who is a beginner at gardening. He is trying to plant something. He bought a pre-packed plant with soil inside a can. He just put the seeds in the soil and borrowed my sprayer to spray the soil everyday (a small sprayer which I use to spray off any soil attached to my mother-in-law's tongue's base).

However, I am thinking that the water molecules created by the spray are too small and less dense than the water in a water container such as cup. I wonder if any of the water reaches to the bottom.

My thinking is the spray could wet the soil at the top and the seeds can germinate. However, when the plant grows and its root are going deeper in the soil the sprayer might not be suitable anymore. What do you think?

Answer 1

It depends on what kind of spray it is. For example, if it is a hosepipe attachment then it is probably delivering almost the same amount of water as a hosepipe. However, a small hand spray is not going to deliver much water at all.

You are talking about water molecules, which implies an atomizer. These are really fine water sprays - the water will blow like a cloud. The closest I've seen for horticultural use are in tropical greenhouses where they are used to provide a very high humidity.

Here are some things to bear in mind when considering how to deliver water:

• Is the correct amount of water being applied? The plant should not be waterlogged, nor should it be too dry.
• Is the water getting to where it needs to be? A spray will tend to hit foliage which might be damaging. A single stream of water is easier to direct to the soil below the plant.
• Avoid soil erosion. A single stream in one place, or a high pressure spray (some sprays increase the pressure because the nozzles are smaller) can lead to erosion if you are not careful.

After saying all that, for seeds, I would carefully pour water in for delicate seedtrays, or use a soaking spray that soaks to the level that contains the seeds: not much for peppers which are very shallow, but Texas red yuccas are deeper, so more water - I also used much deeper pots, so there's no danger of them getting water logged. Note I do not water log the entire pot.

Answer 2

In addition to winwaed's answer...

A good technique for seedlings (not seeds) and potted plants, when you're not sure about how much to water, is to bottom-water. Assuming the pot has drain-holes in the bottom, place the pot in a pan of water an inch or so deep (less for small pots) for 5 or 10 minutes, or until the top of the soil is damp. Be sure the water can get in - that both surfaces aren't flush. The soil will wick up the water, and there's little chance of over-watering. You want the water height to be such that it will get into the pot and wick up, but the height of soil in the pot that's below water level is small relative to the size of the pot. The only case this will cause over-watering is when an extremely heavy, humus-heavy potting soil is used.

With seeds and seedlings, if you over-water the surface you risk getting "damping off" and other problems caused by mildew and mold. You need damp soil, but drier air above it. It's tempting to cover the pot with clear plastic or something to keep it from drying out - don't do it!