Planting a tree, setting fence posts, building a patio or installing irrigation all involve digging, and buried utility lines can sit closer to the surface than most people expect. The national 811 system exists so homeowners and contractors can have those lines marked first. This guide explains how it works and what to do before any landscape project.
Key takeaways
- Contact 811 a few business days before any digging, including planting and fence posts.
- Wait for all utilities to respond and mark their lines before you dig.
- Dig carefully around the marks, and contact 811 again for each new project.
What 811 is
According to the 811 organization, 811 is the national call-before-you-dig number. Anyone planning to dig should call 811 or use their state 811 center’s website a few business days before digging, to request that the approximate location of buried utilities be marked with paint or flags.
Why it matters for landscaping
Hitting a buried line can disrupt utility service, cost money to repair, or cause serious injury or death. The 811 organization notes that many utilities are buried just a few inches below ground, so even small gardening jobs, such as planting flowers or shrubs, can hit a line.
How the process works
When you call 811 from anywhere in the US, you are connected to your state’s 811 center, which asks about the location and details of your project. Online requests use the same information. You receive a ticket number, instructions on how long utilities have to respond and how to confirm that all of them have.
Wait for the marks
State laws vary, but utilities generally have a few days to respond. Locators come to mark the approximate location of their lines with paint or flags in colors that indicate the utility type; for example, gas lines are marked in yellow. Use your ticket information to confirm that every utility has responded before digging.
Dig carefully
Dig carefully around the marks, not on them. The marks show approximate locations, and lines can shift over time with erosion or root growth. The 811 organization advises contacting 811 again each time you plan a new digging job.
811 steps at a glance
| Step | What to do |
|---|---|
| Plan | Know where and how deep you will dig |
| Contact | Call 811 or use your state 811 website a few business days ahead |
| Wait | Allow the required time for utilities to respond |
| Confirm | Check that all utilities responded |
| Dig | Carefully, around the marks |
Lines 811 may not mark
Utility companies mark the lines they own. Lines installed by you or a previous owner, such as cables to a garage or shed, landscape lighting wiring, irrigation pipes or a gas line to a grill, are often private and may not be marked. Ask your 811 center how private lines are handled in your state, and consider hiring a private locator if you know such lines exist.
If you hire a landscaper
Professional landscapers should submit their own locate requests for jobs they dig. Ask about it during the site visit and confirm before work starts. See Questions to Ask a Landscaper Before You Sign.
Tip: Mark the area you plan to dig with white paint or flags before contacting 811, if your state center recommends it. It helps locators know exactly where to mark.
Projects that need 811
- Planting trees and shrubs.
- Setting fence and deck posts.
- Building patios, walkways and retaining walls.
- Installing irrigation or landscape lighting.
- Digging a rain garden or pond.
- Removing stumps.
Which approach fits your project
For a single shrub, the process is the same as for a patio: contact 811 and wait for marks. For large projects, plan the request into the schedule so marks are in place before equipment arrives. For projects near known private lines, add a private locate.
Keeping the marks visible
Marks can fade or be removed by mowing, rain or the work itself. Protect flags and paint during the project, and avoid mowing over flagged areas. If marks disappear before you finish, contact your 811 center about refreshing them rather than guessing. Keep your ticket number handy until the job is done.
Common mistakes
- Assuming shallow digging is safe.
- Digging before all utilities have responded.
- Digging directly on the marks.
- Reusing old marks for a new project.
Frequently asked questions
Do I need to call 811 to plant a tree?
Yes. The 811 organization says any digging requires contacting your 811 center.
How far ahead should I contact 811?
A few business days before digging; the exact time depends on state law.
What do the colors mean?
Each color indicates a utility type. For example, yellow marks gas lines.
Before digging a new bed or tree hole, also read How to Plant a Tree: Step by Step for a Healthy Start.