How to Plant a Tree with Blue Water Baltimore
Thank you for volunteering to plant trees with us! We are so excited to create a cleaner, greener Baltimore together.
In an effort to reduce in-person gatherings and limit demonstrations, please carefully read these how-to-plant tips before attending our events. The most important steps are highlighted in bold.
We ask that you read the whole post, but for reference here’s the short version:
- First, determine the correct hole width & depth. The hole should be 2-3x as wide as the root ball. The top of the root ball must be level with, or slightly above, ground level so that the root flare remains visible.
- Before planting, use a hand rake to loosen circling roots (trees in plastic pots only)
- Gently tamp down the soil with your foot as you back fill.
- Never pile soil or mulch against the trunk!
Tools & Supplies.
Blue Water Baltimore will provide the following tools & supplies for all volunteers. However, if you have your own, feel free to bring them!
- Work gloves
- Shovel (spade for digging, & flat shovel for street tree projects)
- Garden rake (not a typical leaf rake)
- Hand rake
- Hand pruners (bypass)
- Soil knife / cutting tool
- Pick axe / mattock
- Stake pounder
1. Prepare the hole
At most of our planting events, the holes will be pre-dug by our staff using an auger or excavator. This saves you a lot of time & sweat! In most cases, you and your planting team will just need to slightly adjust the hole depth slightly based on the size of your tree’s root ball. The root ball is the name for the mass of roots and soil that the tree grows in before it is transplanted into the ground.
Photo: Blue Water Baltimore’s Restoration Team prediging holes with our excavator for a tree planting in the south Baltimore community of Curtis Bay
Types of trees
Depending on the planting project, our trees come in various sizes and containers.
- For street tree plantings we generally use much larger stock called ‘B&B’s’ or ‘ball & burlap.’ In this case, the root ball is contained in a burlap sack with a wire cage around it. (photo on left).
- For our open space plantings in areas such as parks, schools and private property, we often order containerized trees in plastic pots (photo on right).
Photos: (Left) Our WaterKeeper poses with large B&B (‘ball and burlap’) street trees.
(Right) Smaller containerized trees in plastic pots are used for open space plantings.
Determining hole width
Regardless of how the trees are packaged, the hole should be at least 2-3 times as wide as the root ball and have straight sides and flat, firm bottom so that water does not collect underneath the roots.
Photo: Hole is at least 2x as wide as the container or root ball
Show me your root flare! Determining correct hole depth.
Determining the correct hole depth IS KEY to the long term survival of a new tree.
- First, find the root flare. The ‘root flare’ is the area where the base of the tree trunk flares out or grows wider. This flare is more easily apparent on some trees than others. If you are having trouble finding it, look instead for the topmost structural root extending off the trunk. The root flare is an important site of gas exchange (breathing) for the tree and should remain above the soil. Prolonged moisture against the trunk leads to decay & disease.
- A properly planted tree should have a visible root flare above the ground. All roots should be covered with soil. Exposed roots can dry out and cause health issues for the tree. Take a few moments here to pay attention and be sure you’re getting it right. As always, feel free to ask a staff member for advice.
Photo: The root flare of this Eastern redbud was buried by 4 inches of soil.
Double check your work. Use your shovel handle as a level to measure across the top of the root ball. The handle should touch the top of the root ball as well as the ground on both sides of the hole. Add or remove soil under the root ball until it is level with, or slightly above, the ground. Aim to plant the tree 1 inch too high rather than 1 inch too low because the tree will naturally settle when it is watered.
Photos: Hole depth is the ‘Goldilocks’ of the tree planting process: Not to high, not too low, juuust right!
2. Start excavating
Remove grass & debris first.
If your hole is pre-dug, the auger bit may have mixed in some grass/large rocks or bricks with the rest of the soil. Before digging, sift through this pile and place these materials aside in a separate location from the rest of the soil for now.
Remove excess loose soil.
Our machines may have dropped a lot of extra soil back into the hole. Use your shovel to scoop this out if needed. On the other hand, your hole may be too deep and you might just need to push some of it back into the hole. Note: Keep your grass & soil piles close to the hole for easier access and don’t step on them or compact them. This makes back filling easier later on.
How to use your shovel safely:
Your legs are much stronger than your arms. Take advantage of gravity and send your body weight into the tool. Push your shovel into the ground with your foot and pry up the soil. Jump on your shovel if you feel comfortable.
Pick Axe Safety:
If you’re having trouble digging with your shovel due to rocks and clay, try a pick axe or mattock to break up the soil. Delicate tree roots will have difficulty entering a solid wall of clay and rock, so be sure to dig a wide hole to allow for root growth. Before you swing, make sure that all members of your planting team are out of the way. Start with your hands wide apart on the handle and your dominant hand on top. As you swing, slide the dominant hand down until your hands meet at the bottom of the handle.
Photo: Tool tip: Allow the weight of the tool to do the work for you like this smart volunteer at a planting in Bishop Square Park.
Remember, safety never takes a holiday! 😉
3. Remove tree from container and loosen roots.
- Plastic pot: Gently pull the base of the tree trunk while holding the container still. If it’s not budging, turn the pot on its side on the ground and press gently with your hands or knees. This will loosen the root ball. If roots are growing through the holes at the bottom, you may need to cut the pot.
- Grow Bag: Cut off the fabric with hand pruners or a soil knife. Peel it off from attached roots and dispose in a trash bag.
- Ball & Burlap (Street tree projects): Use wire cutters to cut the cage. Remove as much of the cage and burlap as possible before placing the tree in the hole. This step may have already been done for you by our staff.
Loosen circling roots (for trees in plastic pots only).
When a tree is grown in a plastic pot, its roots try to grow outwards but hit the inside of the pot and begin to form overlapping circles. Circling roots must be teased out and redirected before planting, or they will eventually strangle the tree underground. Use a hand-rake or your fingers to gently pull root tips outward to encourage growth. This may take several minutes if the tree is very “root-bound.” Sometimes, a tree may be so root-bound it must be cut into 4 sections with a soil knife. Note: You do not need to loosen roots for ball & burlap trees.
Photos: The process of loosening circling roots on a containerized willow oak. Be firm but gentle!
Check in with a staff member after this step to make sure you are ready to move ahead!
4. Place the tree in the hole. Time to fill ‘er in!
Pack down the soil.
Before placing your tree in the hole, gently compact the soil at bottom of the hole with your boots to remove air pockets and avoid sinkage later one. We want a solid base for the tree.
Look up. Remove plastic ties & tags.
Before you place your tree in the hole, look up at the top of the branches. Remove all string, ties and tags from the branches. These restrict trunk and branch growth and can cut off nutrients. Dispose of tags properly in a bucket or trash bag. If you skip this step, we may be unable to reach the top of the tree to remove these items once it is planted.
Place and straighten the tree.
Have a team member hold the trunk upright and centered in the hole.
Back fill with native soil.
As you fill in the hole, break up any clumps of soil and use your feet to tamp down lightly as you go. Note: Do not crush the root ball. If the soil is not tamped down, the tree will be unstable and can fall over.
Photo: Two young volunteers gently tamp soil as the hole is refilled. This is also called the ‘tree dance’ 🙂
5. Install a Greenwell Water Saver:
Don’t forget: When you are almost finished back filling, its time to install the Greenwell Water Saver. This plastic ring goes around the tree trunk, locks in, and is buried by about two inches of soil. The Greenwell holds water directly over the roots for maximum absorption, a necessity for our compacted clay soils in Baltimore!
Photo: Properly installed Greenwell with up-side-down grass clumps around the edge.
6. Mulch & Clean Up
Mulch in a donut shape.
Mulch is made of wood-chips. It retains moisture and delays weed growth, but if applied improperly it can kill a tree. Apply an entire bag of mulch 2-4” inches thick in a circle around the disturbed area. For street tree beds, we will use multiple bags. Do not pile the mulch against the trunk of the tree – this blocks important gas exchange at the root flare and leads to bark decay! Leave an open space in the middle with just a very small amount of mulch inside the Greenwell. Think mulch donut, not volcano. Check out our mulch madness blog for more more tips.
Grass & large rocks.
If applicable, place any grass clumps up-side-down in a circle around the edge of the Greenwell. Grass can compete with trees for much-needed water and nutrients so we do not want it to grow back for the first several years. Plus, the dying grass will form a berm that holds water over the roots.
If you unearthed any large rocks (larger than your fist) or bricks, we will most likely need to dispose of these offsite. Please create a neat pile for our staff to pick up.
Clean up the area.
Use a flat shovel, rake or push broom to clean up the surrounding area of any excess soil. It is important to leave our work area clean for neighbors who use the space.
7. Stake & Protect Your Tree
At Blue Water Baltimore, we stake all of our trees for at least one year after planting.
Stake pounder safety
A stake pounder is a helpful tool, but must to be used with extreme care & attention.
- Never lift the tool over your head. Tilt the wooden tree stake low to the ground when placing the stake pounder over the top. Only then should you raise the stake up vertically.
- As you pound, keep your head up.
- Do short, repetitive hits rather than long, hard strokes to avoid catching the top of the stake on the lip of the pounder.
- Go slow and let the weight of the tool do the work for you. Our staff will lead a in-person safety demonstration on this tool.
How many stakes?
For street trees and open space sites without deer present, we install two stakes opposite one another on either side of the tree trunk. Stakes should be inserted at least 12 inches into the ground and roughly two feet from the trunk, just outside the disturbed soil/ mulch ring. Place all stakes parallel to the nearest path or roadway for aesthetics and uniformity.
A line of newly planted & staked street trees in the South Baltimore neighborhood of Brooklyn.
|Blue Water Baltimore’s Water Quality Scientist, Barbara, safely pounding stakes next to a sweet gum tree in Hillcrest Park|
Tie the tree to only two stakes. Measure out a piece of green webbing tree tie and wrap it around the tree trunk first, preferably in the top 1/3 of the tree trunk above a branch connection so the tie doesn’t slide down the trunk. Use your soil knife to cut it. Then cross it and tie it around the stakes with a square knot.
The ties should be taut but not too tight, allowing the tree flexibility to blow in the wind. Tight ties can lead to girdling and lack of root growth & stability if not properly maintained.
Use a staple gun to add only ONE staple to keep the tie from sagging.
Photo: proper tree tie installation.
Protect the trunk.
As you are working, be aware of sharp tools cutting the trunk. Wounded trees never heal – they merely compartmentalize, or block off, the injured area. Young trees that have just been transplanted are often already in stress mode, and additional damages lead to long-term health issues.
Mower guards & deer protection:
If deer are present in the area, we install 3 stakes in an equilateral triangle with the tree at center. Plastic fencing is then wrapped around the stakes. Deer eat young leaves and rub their antlers on trunks, which can harm or kill young trees.
|Deer rub damage to a young tree in Forest Park Golf Course.||Properly installed stakes and fencing keeps deer from harming young trees.|
Install a plastic mesh mower guard around the base of your tree. Use a hand pruner to cut your mower guard so that it protects the exposed trunk. Use 2-3 pieces of black plastic chain-lock tie to secure it. Most trees are planted in grassy areas where weed wackers and lawn mowers damage the trunks. These wounds can shorten a tree’s lifespan or kill it outright.
|Weed wacker damage on an unprotected oak tree||Mower guards & mulch rings are a life saver!|
Toward the end of the planting event, we will ask a small group of volunteers to help us water all of the trees. Blue Water Baltimore will continue routine watering for the following two summers to ensure long-term survival. For more details on how to water, check out our watering blog.
9. Take a photo
You’ve worked hard today, so take a photo with your new leafy friend & share it with your community! Tag us on social media @bluewaterbmore or send images to [email protected]
10. Sit Back & Enjoy!
Your new tree will improve the local community and wider environment for all residents.
Tree planting is best when done in community so be sure to invite all your friends to sign up for the next event!
Photo: A volunteer relaxes next to her new tree after a planting along Broening Highway near the Port of Baltimore.
Finally, check out this great tree planting video from our wonderful partners at TreeBaltimore!
This video is specifically created for recipients of their free tree giveaway program who are working with containerized trees, so start watching at 1:20 for the most relevant information to our projects. It provides helpful insights into the problems with circling roots and how to determine correct hole depth.