The #1 most often asked question here at Suburban Bonsai is, “When do I water my new Bonsai?” My stock answer is “I don’t know.” I have been involved with horticulture for over 60 years, but I don’t know. The following will explain why. If you purchased 3 identical Bonsai, and they were in the same identical bonai containers, then brought to the same home, but placed in 3 different rooms, it is very likely their watering schedules would be different. So what’s the answer? Maybe touch the top of the soil with our thumb. If it’s dry, we’ll soak that baby – Right? NO-NO-NO. First, I checked with my spiritual leader. He assured me that’s not why God gave us a thumb. Plus, when you check the soil with your thumb, you’re only checking the topmost soil (where there aren’t any roots) for moisture. This area of soil (especially in the winter) will almost always be dry. If you water with this method, you will surely kill your beautiful new bonsai with too much TLC and too much water.
So... What’s the best, easiest, and cheapest method to determine when to water your Bonsai? Simple... take a pencil. Place it into the soil at the corner of the container, where there are few or no roots, about 1” – 1 ½” deep (where the roots are, and where winter’s heat won’t effect the moisture content of the soil). If the pencil comes out wet, DON’T WATER. If it comes out dry – WATER. If it comes out damp, DON’T WATER. If folks didn’t over water, our sales would be 30% less.
“Ok... so now that I know when I must water, how do I do so? Water the top like grandma did???” NO,NO,NO. Imagine a brand new dry sponge, right out of the package. It will not absorb a liquid spill. It must first be moistened to work. Dry sponges and dry soil both repel water. Best method... Take a shallow tray, large enough to accommodate the bonsai container. Fill with 1” – 1 ½” water, and let stand until the water is close to room temperature. Then place the bonsai container in the tray. When the top of the bonsai soil has turned color, the bonsai has been thoroughly watered. So what’s the moral to the story? The pencil may be the most important Bonsai tool you have (not your thumb).
Humidity trays... They are shallow trays filled with water. Gravel is placed to a level higher than the tray itself. The humidity tray is for humidity only – not for watering. If the bonsai container sits above the water level, because it’s sitting on top of gravel, that is higher than the water, then the bottom of the Bonsai soil will be unable to “Wick Up” any water. If the gravel is not high enough, the soil will sit in water, killing the plant within a few short weeks or less.
Other hints... Misting is good, especially in the winter when the heat is on (mornings are best). Locate the bonsai away from heat and AC vents, doors, and drafts. Sometimes bring your bonsai (and other plants) to the bathroom for a day or more. This will give them extra humidity. Plus, it’s a great place to meet with all your friends and show off your Bonsai.
Good luck with your new Bonsai!
Lorraine & Bob BonGiorno
211 Burrs Lane
Dix Hills, NY 11746