This hint will be useful for my herb/salad greens containers near the kitchen door:
From Garden Gate magazine:
Filling in a container
Have you ever emptied your containers at the end of the season only
to find that the roots didn't even reach the soil in the bottom of
the pot? This always seems like such a waste of potting soil and the
money spent on it!
In deep pots, you can save money by using filler material. You can
use anything, from packing peanuts to empty soda bottles. Just make
sure that water can drain through it. Put packing peanuts in a
plastic or mesh bag to make cleanup at the end of the season easier.
And in big containers, you can use empty 2-liter bottles with the
lids on. They take up space and don't let water pool and stagnate
inside.
For shrubs or perennials, it's still worth the soil to fill the
entire container. These plants need more room to grow roots than
their annual counterparts do. And the more soil in the container,
the better it'll hold moisture, which translates into less watering
for you.
Deep containers
Great idea, Yuska! I've done similar things with an especially deep container, but it's nice to see that someone 'official' agrees with me!
xxx Carrie
I've used the packing peanuts for years and they work for me !
I would add that I use landscape fabric on top of them before the soil so you don't have the soil fall through the big holes between the peanuts. I have also found that the peanuts can retain moisture for the pot which can be helpfull if they are in the right spot.
Ann
I've used both empty plastic bottles and peanuts -- both worked great!
I tie my peanuts up in plastic walmart bags and put them in the bottom of the pots.. that way when I dump the dirt at the end of the year, the peanuts come out neatly, in bags and can be reused.
I love the idea of the landscape fabric-Excellent!! I will definitely use that next season!!
I wouldn't argue the point that you can save money by adding a drainage layer to the bottom of containers, or that you can lighten the container by using packing peanuts, but I would be glad to discuss the science involved with why "drainage layers" do nothing to improve drainage and in many cases actually are harmful - especially to unestablished plantings.
If the soil at the bottom of your container is soggy and devoid of roots, it's because the container is too large for the water holding capacity of the soil being used or you are over-watering (Roots cannot grow or metabolize in soils that are devoid of O2; this includes saturated soil sitting atop a drainage layer). A drainage layer simply moves the layer of saturated soil higher in the container. Your planting may tolerate the "drainage layer" because you are growing in a smaller volume of soil and the total volume of water it will hold is such that the plant is able to use it before roots rot. A solid piece of concrete in the bottom of the container would serve exactly the same purpose so long as soil water could flow to the container drain hole.
You would be better served to adjust the speed of soil drainage (and aeration - they go hand in hand) and grow in a container filled with soil than to limit available soil via the addition of drainage material.
Al
Point well taken, Al. The advantage as I saw it was to use the containers I have rather than buying more and more pots. The salad crops I'm growing are shallow-rooted and I'm careful to make sure there is more than enough soil depth to accommodate them. I'm careful not to overwater and I know that aeration is essential. I have used rocks before covered with a layer of mesh, but the weight makes the container hard for me to move should I need to. This idea may not be a perfect solution, but is worth the experiment, IMO.
Yuska
I use inverted plastic pots in the bottom of my whiskey barrell halves. Works well and is a good way to use chipped old pots from nurseries.
Neal.