Aftercare of divisions is critical when you’re slicing and dicing up your plants. Here are a few things to try or to avoid during the critical reestablishing period.
• How about a little shade? The top half of your division is not clueless about what is going on below: Roots and shoots communicate through hormones and other chemical messengers. If you have divided your plant when it had some foliage in place already, the shock to the root system will be communicated to leaf stomata—pores that open and close to allow gas exchange, including water vapor. Stomata respond to many water stresses by closing. However, if leaves are exposed to the hot sun, stomata must open in order to provide evaporative cooling, and this means more water loss (remember the part where your plant has no root hairs?). You can help curb water loss by protecting a division that has top growth from the blazing sun with a little temporary shade (photo above).
• Don’t feed me! Give your plant time to grow new roots and new root hairs. Fertilizing could potentially draw water out of the roots by osmotic action—a move in the wrong direction. Wait at least three weeks before considering fertilization.
• Avoid “Goldilocks watering.” Providing the “just-right” degree of soil moisture at this time is important. Your newly divided plant needs time to grow new roots, and roots need both air and water to function. Standing or constant water pushes air out and promotes root rot and fungal growth. Too little means newly forming root hairs will shrivel and more resources will be tapped to grow new ones, further delaying the return of water to stems and leaves. Established plants can deal with some extremes, but give your divisions a little extra TLC. They will pay it back in short order.