Cullen: Why Fall is for Planting
September 30 2011
By Mark Cullen
We stood in the middle of his field of sugar maples with the victim in hand. Woody roots protruded randomly from the young tree’s main trunk. Absent were the young, hairy feeding roots that provide the highway for moisture and nutrition from the depths of the soil.
As I explained the need for the hairy “primary” roots and the vital role they play, I could see the light come on in the property owner’s mind. “Now that explains why this tree didn’t make it,” he exclaimed.
Your understanding of how plants work can have a powerful effect on your success rate in the garden, but you don’t need a post-secondary education on plant life.
I am here to clear up any confusion on the subject of “what plants want.” There are no guarantees you will learn all that you need to know, but this column will arm you with the confidence to go out into the world of plants and put them in the ground knowing you did the best you could. You will probably do better than most, including some of the so-called professionals who make huge planting mistakes from time to time.
Fall is for planting. We have been saying this in the business for almost 25 years — ever since growers started producing trees, shrubs and evergreens in containers. I like planting now and generally I have more success with September and October planting than I do with spring planting.
With the cool temperatures of fall, the “top growth” of winter-hardy woody perennials slows and hardens off. At the same time, the roots are busy putting down young feeding roots — yes the same ones the aforementioned maple tree did not have — which will provide support for substantial growth come spring.
No plant will perform well without strong, healthy roots. Put another way, the only way a newly planted tree, shrub, evergreen or rose will grow and thrive in your garden is after it has developed a system of roots that will support the top growth that we see and wait for so anxiously after planting.
While shopping at the nursery, you will know a woody plant has the right kind of roots by pulling it out of the pot. You don’t have to yank it all the way out, just far enough to see the extent to which the roots fill the pot. If they completely fill or turn around the interior contour of it, you have a potential problem.
Ideally you should buy plants that fill about half of the pot with roots; the other half should be the soil mix. This plant needs no lessons on how to grow. It will hit the new soil at your home running (in “plant speak”). Planted in the Toronto area in September or early October, most nursery stock will put down new roots before the hard frost of late November or December. The new root growth will benefit you in the long run, as you can gain up to one year’s growth over the specimens you plant next spring.
If the plant is too big to pull out of the pot, push your finger through the soil surface. If that’s impossible, chances are pretty good the whole pot is full of roots — not a good sign.
Second only to buying a quality plant is the preparation of the planting hole.
Dig a hole at least twice as wide as the root mass and 1.5 times as deep. Backfill it with quality triple mix (equal parts top soil/peat/compost), place the plant in the hole and top up with more triple mix. Stomp the soil with the heel of your boot to get it in firm contact with the roots. By doing this you are sending a message to the roots that it is time to find a new home and get growing. Set the plant a few centimetres above grade for proper drainage, allowing the water to drain away from the centre of the plant, not into it.
I realize you can’t always choose a plant with perfect roots. If you bring home nursery stock that is pot-bound, or even partially pot-bound, be sure to loosen the circular mass of roots using a sturdy knife or even the tip of a small trowel. You will do some ripping and tearing in the process and you may worry you are somehow harming the plant. Not so. You can remove up to one-third of the roots without damaging the plant.
Once planted, the plant will enjoy nothing more than a good, deep drink of water. The addition of a “starter” fertilizer is popular and I have no doubt it helps. The usual formula of a liquid 5-15-5 with butyric acid is designed to encourage the development of roots early on.
It is important not to let your new plants dry out, but also not to kill them with more water than they can digest. As a rule, I suggest putting your finger in the soil about four to five centimetres deep; if the soil is dry it is time to water. Plants love nothing more than the oxygen-charged, warm water from a rain barrel.
As winter approaches you will have plants in the ground that will thrive next spring. You will have taken advantage of many fall discounts at nursery retailers and you will be planting in some of the most pleasant temperatures for outdoor activity.
Fall planting: you win, no matter how you look at it.