Watering in the Zone

Following is more about watering indoor plants continued from this post.  

A term often used in houseplant watering advice is “evenly moist”. To me it’s a rather vague and ambiguous term. I Googled it and got over 50 thousand hits. Scan through them and see if you can understand what it means. 

I think of evenly moist in terms of even distribution of the water throughout the plant container with the media being neither too wet nor too dry. My concept of this is a "zone" of moisture maintained at an optimum level. 

The trick is to find the zone of moisture and to maintain it on a consistent basis. Wide swings in moisture level create a stress that plants don’t need any more than animals. 

One of the best ways to learn about the evenly moist zone is to use a scale along with sub-irrigation pop bottle planters. These are better for plants and the method is much easier to learn than “poke and pour” drain hole watering. 

Unlike opaque plastic grower and clay pots, you can easily see what is going on with the soil and root system. You'll find that very helpful.  

Top watering may be intuitive and seem the logical way to water but it isn’t the best way. Evidence of this is the abundance of photos of weak and sickly looking houseplants all over the web. I see them every day in my blogging research. 

The Dracaena Janet Craig ‘Compacta’ plant in the photo is a new one, which I’ll use to demonstrate what I do. First, I transferred it from the 4” grower pot to a 1-liter pop bottle planter. The media is half potting mix (Fafard) and half coir. 

After the transfer, I flooded the planter and let all the water drain through. The soil is wet rather than moist. As you can see, it now weighs 18 ounces. 

I won’t weigh it again until Monday of the next 7-day watering cycle. It will not get more water until the soil surface dries to a depth of ½” or so. I’ll know then that it’s in the zone. Many will be surprised by how little water this plant uses.  

For learning purposes observe your plant on a daily basis and see the soil color change as it looses moisture. 

Also, check the weight with a scale (and record it). If the weight does not go down, you know that there isn’t enough light. If the plant is not using water, there will be insufficient oxygen in the media and the plant will decline and eventually die, as it’s vital root system rots away. 

It’s also an interesting exercise to lift the planter and experience “weighing” by muscle memory. Note that the pop bottle planter weighs next to nothing so you will be lifting mostly the weight of the soil. The plant weighs very little. 

I can now measure the water to make my coffee within an ounce before putting the carafe on the scale. I found that most interesting.

So…look, weigh and lift and you’ll learn a lot about how plants function. Life in the zone with this plant will be continued. Stay tuned... 

Comments

[Rodolphe]

Great, can't wait to see the next episode! :)

[Greenscaper Bob]

Isn't this exciting? ;-)