Repeat this two or three times at five-day intervals to keep ahead of renewed infestations from surviving eggs. Use a magnifier to inspect the foliage every two weeks, and squash any hatchlings before lasting damage is done. Pamper the plant until you see recovery at hand. You'll know you have a chance when new growth comes and is not immediately sucked dry by insects or aborted as roots die of herbicide poisoning. It will be an uphill fight, as central heating takes us into dry air season, and the shortest days of the year are at hand.
Low light means low energy and slow recovery in a plant.
They're up by the hoards. Let them profit from each other's company until spring. A continuous cover of little leaves traps heat from the soil that helps the seedlings keep growing longer. In April, thin them to stand 8 to 10 inches apart. Janet Macunovich is an advanced master gardener specializing in ornamental plants.