Perfect Time to Plant a Tree… or Shrub
There is an old saying that the best time to plant a tree is 20 years ago, but the second-best time to plant a tree is today. I would go one step further and say the best time to plant a tree is in the fall, and for that matter it’s also the best time to plant a shrub. This may seem contrary since spring is the official season for planting all things, isn’t it? Actually, it depends on where in the world you live, but in our neck of the woods with mild wet winters and hot dry summers, fall is best.
To understand why we have to go back to the roots… tree roots. When you plant a tree in the fall the ground is still relatively warm having just come through summer, and the air is cool. This means that a newly planted tree can put energy into growing roots, because the soil is warm and active. In contrast the air is cooling so the above ground growth (leaves and or needles) is low. Conversely, a tree planted in the spring is going into cold soil having just come through the winter months and the air is warming which will kick the above ground growth into action. So, to recap, fall planted trees/shrubs can concentrate their energy into roots whereas spring planted trees/shrubs have to support both root and shoot growth.
The other benefit to a tree/shrub having time to grow some roots before going dormant for the winter, is that when they wake up in the spring, they have a head start. Fall plantings will have a more developed root system by summer which is going to be a huge benefit when the summer drought hits. A major cause of new tree mortality is inadequate watering during the first few years. But I get it, summer vacation, trips to the beach, watering restrictions… who has time to water the new tree. But the more roots it has established the more likely it will be able to fend for itself, at least a little bit… you still need to water. If you really want to set yourself up for success to survive summer drought, get a tree watering bag. These bags are placed at the base of the tree, filled with water they slowly release it to irrigate. All you have to do is check to make sure that you keep water in the bag. So, fall planted tree and shrubs mean potentially less work for you in the summer, and less likelihood of your tree/shrub dying on you.
Planting Tips for Trees and Shrubs
So now you know when to plant your new tree or shrub, there are a few things you should consider about how to plant, other than green side up (as my father tends to try and simplify it). The first is know your space and then read your labels. Too many times I find myself advising a gardener on what to do with a tree that is planted in the wrong spot, like right next the house under the eaves. The adorable little tree you fell in love with at the garden centre might just top out at 30-40 feet after a few years. Read the listed height at maturity and canopy shape and spread. You need to think in terms of the future and the space it will ultimately fill.
Also think about what you want, do you love fall colours? Then look for a deciduous tree with knock out colour like a Persian ironwood (Parrotia persica), maple or a sourwood (Oxydendron arboreum). Can’t get enough of spring flowers? Consider a magnolia, snowbell (Styrax japonicus) or flowering cherry (*not available for sale or planting in the Okanagan). Need to block a less than lovely view or looking to create privacy? Then something evergreen is the way to go. Do a bit of research or head down to the garden centre armed with the knowledge of the space you have and what you like and then find something that works for you.
Once you have your tree/shrub then you are going to need to dig a hole. It does need to be stated that you need to know what is going on below ground before you start digging. It is surprising in high density urban landscapes how much is going on just below the surface. So be sure to do your due diligence and have a good look around you site and make some phone calls to make sure you are being safe.
The hole you dig in a perfect world should be 2-3 times bigger than the root ball. If the tree/shrub is balled and burlap then carefully cut away the twine and unwrap the burlap, being careful not to disturb or damage the roots, if you don’t get all the burlap off then don’t sweat it… it will eventually decompose. If your tree/shrub is in a pot then lay it down and tap the side of the pot so you can ease it out. Look for any roots that are circling the pot or tightly matted. You want to try not to disturb the roots too much but if you have a root bound tree/shrub you will need to tease some of the roots out so that they won’t just keep growing in a circle and eventually strangle the plant. So, tease the roots, but not too much.
Put your plant into the hole and then stop to take a good look at how it is sitting. It is really important that the tree is not too deep or too shallow. The top of the root ball needs to be flush with the soil level (you don’t want to bury the trunk or have the roots exposed). This is an important point since a tree that is planted too deep or too shallow will always be at a disadvantage. We want our trees to have the best possible chance. Also make sure you’ve turned your tree/shrub to be oriented correctly, thinking about how the branches are forming and the overall shape… it’s really hard to turn a tree after the fact.
Another area of contention surrounds fertilization and soil amendments. My advice is when first planting, don’t add to much amendments. You don’t want to make the soil where you are planting too different in nutrients that the native soil or the roots won’t have any reason to grow out (it’s almost like a form of in situ container gardening). You want roots to move out and establish. A lot of people swear by an application of bone meal to help strengthen the roots. I generally recommend using a mycorrhizal amendment like the brand Myke. There is a formulation just for trees and shrubs and it is a natural way of increasing the root capacity of your plants. There will be lots of time in the spring, when things are really growing to add fertilizer and other growing amendments.