Beginner Gardening: Should I repot my Desert Rose?, 1 by tapla

tapla wrote:
I forgot that I was active on this thread and haven't been following it too closely, but if FC is still around, I'd like to say that people who parrot the old 'you should only pot up one size' advice haven't yet learned that appropriate pot size isn't determined by how large the last pot was, or even by the size of the plant material; it's determined by the soil.

If you scroll up to my post of March 15, you'll see a picture of a soil that would literally allow you to grow any of the plants you pictured in a 55 gallon drum full of soil. If you tried that with a peat-based soil, it would be a death sentence, but when using a soil that is made of particles too large to support perched water, there are no upper limits to pot size because the entire soil mass remains well aerated and absent of perched water, which is the cultural condition that allows the fungaluglies that cause root rot to get a toe hold.

Plants grow best when roots have room to run and don't have to compete with each other for space. Growth and vitality begins to be negatively affected at about the point where the root/soil mass can be lifted from the pot intact. Being able to pot in large pots when you want the plant to add mass is a very large advantage, because small pots are limiting.

The advice so often given to pot in small pots and keep roots tight is appropriate for certain plants that don't like wet feet for only two reasons. The first is, the smaller soil volumes hold less water, so air returns to the entire soil mass faster. However, this advice ASSUMES that you'll be using a peat-based, water-retentive soil, and is given to protect you from yourself. The advice is totally inappropriate if you have as a goal a speedy increase in plant mass and are using a soil like that I referred you to above ...........; UNLESS, the plant is as large as you want it to be and you want to increase the number of blooms. Tight roots are stressful to all plants, and the stress has the tendency to increase the number of blooms. If I might wax anthropomorphic for a moment: The plant feels threatened by the stress, so concentrates it's energy on reproducing to ensure that it's genes are passed along. This actually taxes the plant and lowers it's energy reserves and reduces it's metabolic rate and the by-products of that metabolism it uses in its own defense against disease and even insect predation. IOW, it weakens the plant, reduces vitality, and slows growth.

LP - I would trim off the dead parts and dust fresh cuts with powdered sulfur as a fungicide. Allow it to callous for a week or so, then plant. Mist the soil surface lightly until you see signs of new growth, then water.

Soil choice/composition is a very important consideration and often determines whether your job will be easy or if you will be fighting the medium for the life of the planting. If you can lose the idea that container soils need to be rich and black to be productive, and replace it with the idea that they only need to be well aerated and hold no (or very little) perched water (especially for plants in shallow pots and those that don't tolerate wet feet), you'll probably take a giant step forward in the ease with which you can consistently produce healthy attractive plants.

I'm not being cocky or over-confident when I say that. I've been around Dave's and GW for a good number of years, and can link you to threads I've written about the importance of media choices that illustrate through the participation of (literally) thousands of others that not only does what I'm saying make sound scientific sense, it works extremely well in practical application.

Good luck to you guys!

Al