The advent of autumn means it’s time to plant woody plants.
The reason for planting in the fall is due to woody plants’ cycle of energy, which has everything to do with them being perennials. A soybean or a corn plant germinates as a seed in the spring, puts down roots and punches out leaves to pour energy into making more seeds. It has to do all that before the weather turns cold and usually finishes up within 180 days. The plant lives only about six months, and then it is up to the next generation.
If a plant is going to be durable and last many years, it has to find a way to either stay in operation year-round or find a way to temporarily shut down when “business is bad.” Then, when the market turns around (i.e. warm weather returns), the plant must have enough working capital banked to get through startup costs in the spring.
Dormancy doesn’t mean a woody plant is inactive; it is working hard throughout the winter to get ready for spring. When the plant senses growing conditions are present, it makes a withdrawal from its energy bank and sets up its leaves, which are like independent subcontractors. The leaves start repaying the tree for the loan and have repaid the debt by mid-May or early June.
The remainder of the leaves’ energy is profit for the rest of the year. It uses this energy profit for maintenance; to extend its reach; to gain mass; to produce flowers, seeds, defensive chemicals and structures; and to store away energy for next year.
There is a pattern to growth in woody plants. The energy level drops as stored energy is mobilized in spring and spent to produce new leaves. The leaves start refilling the energy bank. The twigs, to which the leaves are directly attached, get first crack at the energy produced. A twig will grow a new ring of wood and fill it with energy. Then, this branchlet gets the next slug of energy and grows its new ring of wood and fills it with energy.
The pattern repeats with branches, then limbs and next a trunk, as wood production cascades down the tree. The trunk may not put on its wood until November or December, but the woodys are not done yet. Over the winter, the energy flows to the roots, which grow, expand into new soil and make new mycorrhizal roots with their buddy fungi, many of which now are spreading their spores. That’s why you’ve likely seen mushrooms and puffballs popping out of the ground during the past month.
The roots have that short window during the winter to grow enough of a root system to match the top of the plant and be ready for the growing-season demands for water and minerals.
So, now you understand why autumn is planting season for woody plants. It is their natural cadence to grow roots in the winter. But there is nothing natural about cutting 95 percent of a woody plant’s roots off, yanking it from the ground and plopping it down is a new, totally foreign site. Transplanting is as traumatic to a woody plant as a heart transplant would be to a human. A transplanted woody plant has a tall order to fill. It is not just expanding an existing root system; it is charged with replacing all the roots that were chopped off, creating new mycorrhizal roots and getting enough of a new root system in place to prevent next season’s leaves from cooking in the sun.
It’s not just a tall order; it’s nearly impossible.
To give the plant time to replace as much of the root system as possible, we try to plant as early as we can in autumn. Even when we give a plant all these advantages, it usually cannot replace enough of its root system that first year. The plant might sit for a couple years, not showing much top growth at all. However, all that time, the plant furiously is trying to grow more roots.
A plant can only have as many leaves as it has roots to support them. It will not start to grow up top again until it has replaced the missing root system and brought the top and roots back into balance.
This is right about the time the botanically ignorant (I’m being as kind as I can) decide it would be good to fertilize a newly planted tree or shrub with nitrogen-containing fertilizer. Nitrogen (basically cocaine for woody plants) forces the plant to produce more leaves even if it does not have enough roots to support the leaves it already has. Worse, it diverts energy from root growth to leaf growth.
When the tree predictably starts to die as leaves are scorched off, the botanically ignorant say, “Why, it must have been a bad plant or a lousy nursery that grew the plant.” In reality, the genius who applied the fertilizer might not be as smart as he clearly thinks he is. These often are the same professionals of botanical malpractice who decide to prune out half the leaves and branches from a newly planted woody “to balance the top with the roots,” oblivious to the fact that it is the leaves that produce the energy to grow the roots.
Some plants live in spite of the “care” they’re given. Just like those who over-fertilize centipede grass and then act surprised when the lawn tanks, woody abusers present the dogwood growing in full sun as proof that dogwoods like full sun. Don’t look too closely, though, or you might see the sun-scalded bark, scorched leaves, anthracnose and dogwood borer, all of which are hallmarks of how much dogwoods “love” full sun. I have seen squirrels with more planting sense.
There is a tried-and-tested system for planting woodys, yet we do not use it with woody plants in our landscapes. Instead, we practice traumatic, unnatural transplanting. If you expect success with transplanting woody plants, it is important to know how they work and what they need.