Sunday, February 24, 2013

Stepping Up

Welcome Back!!
Actually, that is probably what you are saying to me. I have been absent for quite sometime now. No, I haven't been on vacation, nor have I been sick. The truth of the matter is, I got incredibly busy (I won't bore you with all the details) and I also had a severe case of writers block. I thought I had come up with a good topic a couple of times, then, when I sat down to write it, there was nothing there.
Hopefully, that time off has fixed my head.....Yes, I wrote that so you can fill in your own jokes.
Spring is quickly approaching, at least the calender says so. Mother Nature may have a thing or two to say about that, especially for those of you buried in snow or expecting more!  Either way, it will soon be time to repot many of your plants that have been sitting there all Winter.
Are you ready?
I could write an entire article on how do you know when it is time to repot a plant and I might just do that in the near future. Here is a brief idea of how you can tell. If you can see roots on the surface of the soil or emerging from the drainage hole in the bottom of the pot. If your plant is just not looking well or has completely stopped growing, especially in the growing season it is probably time to repot.
Today however, I want to talk about pot size and which one you should go up to.
I found this picture of the industry standard pot sizes. There are, of course, many in between sizes and the 25 looks more like a 30 to me, but it at least gives you an idea of comparison.

I have been in many discussions about what size pot to use when repotting a plant. The conventional wisdom is, The new pot should be no more than 2 inches wider at the rim or 2 inches deeper than the old pot.
Why, you might be asking.
There are a couple of reasons.
1)     A pot that is much larger gives the roots too much space to grow into.
2)     A too-large container will also hold too much water and can cause root rot.
3)     It will stunt the plant and make it not grow for a while.
I guess these can be good reasons, though, as in life, every rule has an exception.
Personally, I like to go a couple of sizes up, if possible. A few reasons I might not be able to at any given time would be things like, I don't have a much bigger pot or I don't have enough potting mix.
Yes, I know, then just wait until I do. Time is not always on my side and that plant REALLY needs to be repotted.
Here is my thinking for going ahead and putting them into a bigger pot. I will debunk the above reasons as we go.
“ A pot  that is much larger gives the roots too much space to grow into”. Well then, what happens when you put the plant into the ground? That is a MIGHTY big pot!
It was explained to me like this. If you move into a new, much bigger house than you were living in, you will fill it with stuff. The plant will do the same thing.
With a dumb founded look I said, “AND”!?!
Is that not the purpose of the plant? To grow and produce lots of roots? That person walked away. I am not sure if I ticked them off, or they went off to ponder that. The roots of the plant want to reach out and grow. They have a couple of reasons for their existence, to provide food to the plant and to anchor the plant. The more area they cover, the more secure the plant is in the soil.
“A too-large container will also hold too much water and can cause root rot”. I can almost see this. If you use a very water retentive soil mix and repot a Cactus or some other water sensitive plant, then yes, you are correct. However, if you use a very well draining soil, with lots of perlite or some other course additive, there should be no problem. The container should also have lots of good drainage.
You can also throw into this mix, the difference between clay pots and plastic pots. Plastic will hold water a little better than the clay. I still like the plastic pots better, they are much lighter.
“It will stunt the plant and make it not grow for a while”.
I have actually never seen any evidence of this. It is possible that people that have had this problem injured the roots in some manner. The plant was in shock and had to replenish the root system. While there is active root growth, there will not be any top growth. So it makes sense that the roots are hurt, they are trying to fix themselves and the plant is not growing.
Another reason I tend to go to a much larger pot is plant size. I had a Citrus tree last year that was in a three gallon pot. The tree itself was very tall, but not terribly rootbound, though it was getting there. Every time the least little amount of wind blew, it would tip over. So, I repotted it. I put it in the next size up, a seven gallon. The next day, after some heavy wind overnight, there it was on the ground again. So, needless to say, it was in a fifteen gallon that afternoon. Hasn't tipped over since.
I mentioned I have gotten extremely busy earlier. So, as the old expression goes, “The shoemakers daughter goes barefoot”, I do not always have time to work my yard like I want to. So, when I do have time, and I have a plant that needs to be repotted, I put it in a much bigger pot, it will then be set for a longer period of time.
I know there will be LOTS of disagreement with my thinking on this whole subject. That is fine. Hopefully it will cause some thinking and maybe help somebody that is on the fence about what size they should use.
As always, if you have any questions, or if you want to discuss this further with me, I am only an e-mail
Happy Growing!

1 comment:

  1. Hi, Darren,
    I think the real reason for the graduated pot size advice is to sell more pots. It's not like kids being put into shoes that are way too many sizes larger. My sense of root mass size to plant size and height is not offended. A pot size too big is far less harmful (if at all) than the "all roots in a beehive bun and no soil" situation with container-grown citrus.
    I just left the tropics of Southern California, with a too-long vacation in Maui [we are haoles, never to be accepted as locals, even after 5 years] so I had no trouble growing citrus until now, as we moved to the central coastal area of Oregon (zone 8b according to the USDA). I have put too few minutes into restoring a 10x8x7high poly-covered hoop house on our property, with hopes of getting some decent dwarf citrus to live there. I really miss the year-round morning OJ fresh-squozen from the Valencias we had! Have you done any posts about greenhouse citrus?