After harvesting the last of the leaf from my one and only potted plant, a Shirazi placed in a 16" wide x 14" high pot, filled with Miracle Gro Potting Mix, the time had come to remove the stalk and its roots. Out of curiosity, I decided to carefully remove the intact root ball and rinse away the soil. This revealed the extent of the roots of what I considered a pot-bound plant.
The soil available to the plant was 14" wide x 12" deep, after taking into consideration the clear lip of the pot and the 2" of sand and gravel at the bottom. I used a sprayer on a garden hose to remove as much dirt as possible, then hung the stalk and roots on a clothesline, subjected to three days of alternating rain storms and sunshine.
What are missing in the in the photos are all the tiny rootlets that dried out and blew away. There seemed to be tiny roots on every particle of dirt in the dirt ball. Viewing what remaining root there is, even though it has shriveled a bit and drooped downward, we can see that it completely filled the available soil in the pot.
A closer view of the central roots...
...demonstrates that, although there is no major taproot, there are four or five major roots extending directly downward.
What is notable is that the plant seems to have regulated its root growth to the capacity of the pot, unlike some plants that will grow excessive roots that can burst a thin-walled pot. This also suggests to me that tilling for ground-grown tobacco should extend deeper than 12".
Unfortunately, I know of no practical method for revealing a comparable view of the roots from a plant grown in the ground. When we dig out the roots, all we ever see are the thickest of the roots.
Bob
The soil available to the plant was 14" wide x 12" deep, after taking into consideration the clear lip of the pot and the 2" of sand and gravel at the bottom. I used a sprayer on a garden hose to remove as much dirt as possible, then hung the stalk and roots on a clothesline, subjected to three days of alternating rain storms and sunshine.
What are missing in the in the photos are all the tiny rootlets that dried out and blew away. There seemed to be tiny roots on every particle of dirt in the dirt ball. Viewing what remaining root there is, even though it has shriveled a bit and drooped downward, we can see that it completely filled the available soil in the pot.
A closer view of the central roots...
...demonstrates that, although there is no major taproot, there are four or five major roots extending directly downward.
What is notable is that the plant seems to have regulated its root growth to the capacity of the pot, unlike some plants that will grow excessive roots that can burst a thin-walled pot. This also suggests to me that tilling for ground-grown tobacco should extend deeper than 12".
Unfortunately, I know of no practical method for revealing a comparable view of the roots from a plant grown in the ground. When we dig out the roots, all we ever see are the thickest of the roots.
Bob
