When you plant a new tree on your property, you’re both starting a long-term relationship and marking a moment in time. To guarantee the health of your new tree, you’ll need to plant it correctly. So, to help you succeed with tree planting, we’ve put together our top recommendations for how to plant a tree, including common problem areas like planting depth, staking the tree, amending the soil, and watering.
Unfortunately, we see improperly planted trees way too often. We get so many calls from people asking “what’s wrong with my tree?” – often it’s not growing well, the leaves are yellowing or dropping, it’s frequently infested with pests or diseases, or it’s putting out spindly growth on the trunk. What we usually find is that the tree was planted too deep (that’s one of the leading causes of tree death and one of the many expensive tree problems to avoid), the wire cage and burlap were left on, mulch was piled around the base of the tree, and/or it was improperly watered after planting. Many times, the tree was doomed from the start.
That’s why it’s so important to know how to properly plant a tree!
There’s an almost endless amount of information about trees and tree care out there, and you may get conflicting or confusing advice from friends or acquaintances. We’re here to give you a clear, sound foundation of information that will help you and your new tree succeed.
Best Time of Year to Plant a Tree
Fall is for Planting
Fall is an ideal time for planting. The long, hot summer days are waning, evenings are cool, and winter weather is still far off. Autumn is a good tree planting time because:
- Days are still warm and sunny
- Nights are cool but do not yet reach freezing
- Soil is still warm and easily worked
- Rainfall and irrigation water won’t freeze
When to plant trees in fall – We start fall tree planting after Labor Day and continue until we start to see hard freezes, usually toward the end of November.
Spring is for Planting Too
Spring is another good time for tree planting. Plants are waking up from winter dormancy and starting to put out new growth both above and below ground, while summer’s heat and lack of moisture are still months away. Spring is a good tree planting time because:
- Days are warming up but not too hot
- Nights are cool but no longer freezing
- Soil is moist and easily worked
- Rainfall is usually plentiful, providing much of the moisture newly-planted trees need
When to plant trees in spring – We start spring planting when soil has dried out enough to be easily worked without clumping or compacting, and continue until around Memorial Day. After that, temperatures start to rise and newly-planted trees can be overly-stressed by hot, dry summer conditions.
How to Choose a Tree
Not sure what kind of tree you want to plant, or don’t know the name of one you do? The Arbor Day Foundation has lots of information about trees, including their Tree Wizard, an interactive way to find out what tree will work in your location. Try it here!
Connecticut’s Department of Energy and Environmental Protection (DEEP) offers an “Owner’s Manual” for residents who are planning on planting trees. It’s full of information about choosing, planting, and caring for trees. You can download a free copy of it here.
And don’t forget our native trees! Connecticut’s native trees are uniquely suited to thrive in our soils and climate, and many of them would be a beautiful addition to your property. Here are our top recommendations:
Where to Plant a Tree
Right Tree, Right Place
If you want your new tree to thrive, there are several things you should do before, during, and after planting. This is especially true if you’re planting in autumn as you’ll need to prepare your tree for its upcoming long winter nap and next spring’s leaves and flowers.
Location is key. Before you get out your shovel, evaluate your property. Look all around and look up and down. Here are some things that could interfere with your tree’s growth or be damaged by it:
- Sidewalks, driveways, decks, or patios
- Property lines
- Houses, garages, or other existing structures
- Retaining walls
- Overhead utility lines
- Underground sewer lines, tanks, or septic fields
It’s vital to make sure that you choose a tree species that will fit in its new home for its entire lifespan. Be sure you understand how your tree’s mature height and spread will fit in with all the things around it (and how its roots will impact what’s underground). Measure twice, plant once!
Location, Location, Location
You can think of the location for your new tree as its own tiny microclimate. Make sure your chosen planting location can provide all the things your tree will need to establish itself.
- Sunlight is a key component. If your tree needs full sun, planting it in a shady spot can cause long-term problems. A tree’s sunlight requirements are specific to its genus and species, so ask an arborist or nursery professional to make sure you’ve chosen a good candidate for your location.
- Soil volume. Provide your tree with enough soil area to support its growth. Your tree’s roots need room to spread out and down, and you’ll want your tree’s trunk flare to develop without the risk of girdling from circling or kinking roots that have nowhere to grow.
- Water. Give your new tree plenty of water when you transplant it. Both spring and fall weather can be hot, and you don’t want to add lack of water to the stress a tree experiences after transplanting. Slow, deep watering helps your tree to develop roots well below the soil surface, which is where you want them. Irrigation systems for turf do not provide the right kind of water for trees, and they encourage shallow, surface-level roots that don’t work with turf or lawnmowers
- Water II. Your tree needs soil that will drain water instead of holding it. Poorly draining soil can hold water for too long, creating conditions that can suffocate tree roots and encourage soil pathogens.
And of course, you’ll want a good tree to begin with. Choose your tree from a reputable nursery, and always check its rootball to make sure you’re not getting a tree with girdled or kinked roots that will cause problems as your tree grows. Connecticut’s Nursery and Landscape Association provides a map of nurseries throughout the state. You can find one you like here.
How Deep & Wide to Dig a Planting Hole
Digging the Hole
After you bring a new tree home, you’ll need to plant it ASAP. You can prepare a perfect planting hole by following these guidelines:
- Make sure the soil is evenly moist when you dig the hole. If you can, wait for a few days after a good rainfall before planting, or thoroughly water the area a couple of days in advance. This will help ensure your soil has good levels of water and oxygen in it, but is not too heavy to work.
- Dig the planting hole two to three times the width of the tree’s nursery container or its burlap ball, and about the depth of the rootball. What you want is a hole depth that will allow you to position your new tree’s rootball so that its trunk base, or root flare, is just above the surrounding ground level.
- A smooth-walled planting hole will be too solid for roots and root hairs to penetrate, and roots will be trapped in the immediate planting area of the hole you dug. To avoid this, “scarify” the sides of the planting hole with your shovel tip by chipping at the soil to roughen its surface. The openings you make in the side of the planting hole will let young roots penetrate into the surrounding soil.
- Remove any debris, rocks, and chunks of clay or concrete from the soil to keep them from blocking root growth or, in the case of concrete, changing the pH of your soil. Don’t sieve or rototill your soil to make it fine. Native soil is nothing like bagged potting “soil,” and overworking it can cause lasting damage.
How to Find the Right Depth for Planting
It’s not always obvious where the root flare is on a tree that’s growing in a container or that’s been wrapped in burlap. Often, the root flare is buried beneath the growing medium in the container or hidden under layers of soil (or even multiple layers of burlap!) inside the burlap ball.
Before digging your planting hole, pull away soil or potting mix from the trunk of the tree. Keep going until you find the spot where the trunk widens and you start to see the tops of roots. That’s the root flare (or trunk flare) and it should be at the soil surface when the tree is planted. If you can’t see it, the tree is planted too deep!
When the tree is buried deep in the planting container or burlap ball, you’ll sometimes see roots coming out of the trunk above the root flare. Cut these off before planting as they’ll die when exposed to air.
Planting Your Tree
Handling Your Tree
Always lift your tree by its container or burlap root ball and not its trunk. Place the container in your planting hole to check its depth; make sure the top of your tree’s rootball will rest just above the surrounding soil surface. If your hole is too deep, remove the tree and make a mound of soil in the bottom of the hole, then compact it with your foot.
If your tree is in a nursery container, gently work the can from the rootball. Don’t pull the tree out of its container by its trunk or branches!
If your tree is balled and burlapped, leave the burlap on until you position your tree at its right height. Then remove the burlap by cutting it away. Be sure to remove any string tied around the trunk as well. If you can’t pull all of the burlap out from under the rootball, leave the portion beneath the rootball in place but cut all the rest away.
And if the rootball is enclosed in a wire basket, remove all of the basket! Those wires will trap roots and cause them to grow in circles, slowly girdling (strangling) the tree. Don’t worry if the rootball falls apart a bit when you remove the basket; that’s better than leaving the basket in place.
Once the tree is upright in the planting hole and positioned as you like it, backfill in the soil you dug out. Press the soil firmly in place but don’t stomp on it or compact it.
Immediately after, water your tree thoroughly. You want to minimize the shock of transplanting as much as you can, and water stress is the first thing to avoid.
After you water, add a thick layer of mulch around the base of your new tree. Keep it well away from the trunk and never, never pile it in a mound; a donut-like ring is a better option. A three-foot radius out from your tree’s trunk is a good estimate for smaller trees, as it reminds you to not add plants too close to a tree’s trunk, or to use mowers or string trimmers near it. If your tree has a larger canopy, aim to cover the area beneath the entire canopy (out to the drip line).
Amending Soil in the Planting Hole: Yes or No?
When you backfill soil into the planting hole with your new tree, should you amend it with compost or other substances?
It’s a topic of seemingly endless debate. Opinions about amending backfilled soil continue to evolve, and current opinions lean toward not amending backfill. Why? Here are the most important reasons:
- Amending the backfilled soil creates a moat of one type of soil around your new tree’s rootball, while the rest of the surrounding native soil is in its natural state. When this division exists, your tree’s roots may stay within the newly-enriched soil that is less compacted and not venture out into the surrounding soil. When this happens, your tree’s roots will grow around and around in the amended soil, not making an extensive system of spreading, anchoring roots and increasing the chance that circling roots will girdle the tree.
- Native and adapted tree species grow in native soil. Trees that are native to Connecticut have evolved along with the soil in our area. Unless there are known issues with your soil, such as heavy compaction, toxic levels of minerals, or poor water-holding capacity, these trees will grow fine in the soil you have.
A better approach is to amend your soil generally. This involves applying a layer of compost over your soil, scratching it gently into the soil’s surface, and allowing rainfall or irrigation to “melt” the compost into the soil. The nutrient particles in compost are carried into the soil by water and gravity, where they bond to existing, native soil particles. This improved soil naturally holds water longer and stores nutrients for the long-term.
Composting or turning fallen leaves into mulch is an excellent way to improve your soil’s overall health for the long term, to the benefit of all plants and trees that grow in it. Don’t till compost into your soil as this unneeded tilling releases stored carbon into the air instead of leaving it sequestered in the soil, and disturbs the natural structure of native soil. As we all learn more about soil (that it’s a living thing and crucially valuable), one thing repeatedly emerges: the less we disturb soil, the better.
Should You Stake the Tree?
Another oft-argued topic is whether or not to stake newly-planted trees. There’s no one answer, so you’ll need to understand your tree and decide for yourself.
- Young, nursery-grown trees in containers often come with a central stake, for reasons of economy and portability. A tall, narrow tree takes up less room than a spreading one, and young trees can be grown close together and easily moved in their cans. When you plant your young tree and remove its nursery stake, the young tree’s willowy form may need support while its root ball grows.
- When balled and burlapped trees are excavated from the field, their crown may be larger than their excavated rootball can support. In this case, stakes serve to hold the tree in place while the tree’s rootball grows and the tree can stabilize itself.
The best argument for staking is to keep a newly-planted tree from being blown over by strong winds while the tree develops its stabilizing root system. You’ll want to stake for as short a time as possible. To know when to remove stakes, you’ll need to inspect your tree regularly. As soon as your tree flexes and bends in the wind but regains its upright position, and the roots don’t lift as the tree bends, remove its stakes. Freed from its stakes, a young tree will develop a strong trunk and anchoring roots on its own.
Want Some Help?
We LOVE planting trees! And with years of practice in planting nearly every kind of tree imaginable, our arborists know how to do it the right way. We’ve seen too many badly-planted trees dying unnecessarily when a bit of know-how (or professional planting by an arborist) could’ve prevented the problem entirely. So if you’re not sure what tree(s) would be best for your property, don’t have the tools or a strong back to plant it yourself, and just want to be sure it’s done correctly, give us a call at 203-258-5584. We’re happy to help!
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