I GENERALLY HAVE more success with September and October planting than 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, which provide support for substantial growth, come spring.
Remember, no plant will perform well without strong, healthy roots. The only way that 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.
Look for Good Roots
A woody plant has the right kind of roots if, by pulling it partway out of the pot, you can see the extent to which the roots fill it. If they completely fill the pot or turn around the interior contour of it, there may be a problem getting the plant to establish itself in your garden.
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. At your home, it will hit the new soil running. Most fall-planted 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 that you plant next spring.
If you cannot pull the plant out of the pot then push your finger through the surface of the soil. If that is not possible the chances are pretty good that the whole pot is full of roots – not a good sign. I recommend that you take a pass on such root-bound plants.
Dig a hole at least twice as wide as the root mass of the plant and 1.5 times as deep; backfill with quality triple mix (equal parts top soil/peat/compost); place the plant in the hole; and top the hole up with more triple mix. Stomp on it with the heel of your boot to get the soil in firm contact with the roots.
By doing this you are sending a message to the roots that it is indeed 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.
If you do buy nursery stock that is pot-bound or even partially pot-bound, be sure to pull the roots out from the circular mass that they’ve become inside the pot.
Use a sturdy knife or even the tip of a small trowel to get a grip on the roots and pull them out. You will do some ripping and tearing in the process and you may suffer some self-doubt that you are somehow doing the plant harm. Not so. You can remove up to a third of the roots without causing damage to the plant.
Once planted with new soil firmly packed around its roots, the plant will enjoy nothing more than a good, deep drink of water. The addition of a starter fertilizer provides a needed boost of nutrition.
After you have planted your new winter-hardy plants in the garden, it is important not to let them dry out and not to kill them with more water than they can use. As a rule I suggest that you put your finger in the soil about four to five centimetres deep (two to three inches) and if the soil is dry it is time to water. They love nothing more than the oxygen-charged, warm water from a rain barrel.
By planting now, you will take advantage of fall discounts and the most pleasant temperatures for outdoor activity in the whole year. And you will have plants that will thrive next spring.
Mark Cullen appears on Canada AM every Wednesday morning at 8:40. He is the Lawn & Garden Expert for Home Hardware. Sign up for his free monthly newsletter at markcullen.com