Contractile Roots
Contractile roots resemble a relaxed earthworm; new white roots growing from the bottom of the bulb (basal plate) are smooth and white. In crumbly non compacted soil; the lily will actually pull itself deeper than you planted.
The red circled spot is the lily bulb Basal Plate, this is where these new contractile roots are formed and their job is to hold the bulb firmly in place despite wind. The mass of fibrous roots are formed on the underground portion of stem just above the top of the bulb are "feeder" roots - the reason why placing fluffy organics materials such as peat, compost or very well-aged manure in midsummer or fall is beneficial to your lilies. These roots are just under the surface. Although stem roots will also pick up nutrients, it is not as important to add fertilizer to the planting hole because over winter much of it will wash away while the lily is in semi dormancy. The arrow on the left shows a new white root starting and the arrow on the left is an established basal plate root that is branching out.
Years ago, when hand planting a test row of 10 or 15 different varieties, all were placed at the same depth, but when it came time to dig the bulbs for propagation, one noteworthy cultivar, instead of being 8 inches deep, had burrowed its way down over a foot. Because of that trait, it was not selected for commercial propagation for the simple reason our tractor could not pull the bulb digger through the field at that excessive depth.
So, to end this story, provide well-drained soil that is not compacted and don't stress out too much over which way is "up", just remember "roots down" . We like to dig a single hole for three bulbs, one standard shovel size deep, and place each bulb at the side of the hole in a triangle. A planting stake, labeled with the cultivar name, goes in the middle. We use 12 inch long plastic stakes and write the name in permanent marker in two places: so it will be visible above the ground for easy reference, as well as near the base of the stake so the soil will protect the ink from fading over time. Or, you can just bury a second stake at the bottom of the hole. (One year we had difficulties with a cougar "playing" with our field stakes and learned to bury a second marker underground in the back of the field.) After filling the hole to cover the lilies with 4 to 5 inches of soil, the packing material from the poly bag is spread on top to clearly mark the location.
Years ago, when hand planting a test row of 10 or 15 different varieties, all were placed at the same depth, but when it came time to dig the bulbs for propagation, one noteworthy cultivar, instead of being 8 inches deep, had burrowed its way down over a foot. Because of that trait, it was not selected for commercial propagation for the simple reason our tractor could not pull the bulb digger through the field at that excessive depth.
So, to end this story, provide well-drained soil that is not compacted and don't stress out too much over which way is "up", just remember "roots down" . We like to dig a single hole for three bulbs, one standard shovel size deep, and place each bulb at the side of the hole in a triangle. A planting stake, labeled with the cultivar name, goes in the middle. We use 12 inch long plastic stakes and write the name in permanent marker in two places: so it will be visible above the ground for easy reference, as well as near the base of the stake so the soil will protect the ink from fading over time. Or, you can just bury a second stake at the bottom of the hole. (One year we had difficulties with a cougar "playing" with our field stakes and learned to bury a second marker underground in the back of the field.) After filling the hole to cover the lilies with 4 to 5 inches of soil, the packing material from the poly bag is spread on top to clearly mark the location.
