How to Grow Landscape Shrubs — Planting Depth Is Everything

Most shrub failures trace back to one fixable mistake: planting too deep. When the root flare sits below soil level, water pools against the trunk, roots suffocate, and the plant declines over a season or two. The antidote is simple — set the shrub shallow, dig wide, and let water do the settling work. The steps below follow extension-service guidance that applies to container-grown, balled-and-burlapped, and bare-root shrubs alike, and getting it right in the first season pays off for decades.

How to Plant Shrubs: The 7-Step Method That Works

Planting shrubs is a one-hour job that decides the next ten years of the plant’s life. The sequence below matches what university extension services recommend, and each step has a reason behind it.

1. Call before you dig. Florida Extension says to contact underground utility companies before digging deep holes — one phone call avoids a disaster.
2. Pre-water the shrub. If the container feels dry, soak it before planting so the root ball goes in moist, not parched.
3. Dig a wide, shallow hole. Make it at least 1.5 times wider than the root ball — ideally 2–3 times wider (3–5 times if your soil is heavily compacted, per UConn). The hole should be no deeper than the root ball’s height.
4. Loosen circling roots. Gently tease apart or score the root mass on container plants so roots grow outward instead of strangling the plant.
5. Set the shrub at grade. The top of the root ball — where the first main roots meet the trunk, called the flare — should sit at or slightly above soil level. Never lower.
6. Backfill with native soil. Use the soil you dug out, firming it lightly to remove air pockets. Don’t stomp it flat; roots need oxygen too.
7. Water in thoroughly. A deep soaking right after planting settles the soil and closes air gaps. Then mulch with 2–3 inches of organic material, keeping it 2–4 inches away from the stems.

When Should You Plant Shrubs?

Timing matters more for establishment than most gardeners realize. The Royal Horticultural Society says most shrubs are best planted from autumn to spring, as long as the ground isn’t soggy or frozen. Evergreens do especially well in November and March, when warmer soil speeds root growth.

For deciduous shrubs, the New York Botanical Garden recommends planting while the plant is dormant but the soil is unfrozen — typically late fall or early spring. That window gives roots a head start before summer heat arrives, and it means less watering duty during the hottest weeks.

One exception: if you’re installing container-grown shrubs in summer, you can still plant, but plan on more frequent watering through the first season.

How Much Water Do New Shrubs Need?

New shrubs need consistent moisture, not constant soaking. The exact schedule depends on your climate, but extension sources converge on a sensible pattern:

• First 3–4 days: water every day (Iowa State).
• Weeks 2–4: taper to every other day as roots begin to establish.
• After 3–4 weeks: a thorough watering every 7–10 days in dry weather is often enough, per Iowa State.
• Hot, dry spells: DCMGA recommends about 1 gallon once a week, increasing to twice weekly in heat — for the first two years.

The common failure is overwatering — roots can suffocate or rot in soggy soil, so check moisture before adding more.

Common Shrub-Planting Mistakes to Avoid

Knowing what not to do is half the battle. The most repeated warnings from extension services all trace back to a few habits:

Planting too deep. This is the number-one killer. When the trunk flare sits below grade, moisture collects against the bark and roots can’t breathe. If you’re unsure, err on the side of shallow — a slightly high root ball settles into place.

Piling mulch against the stem. That classic “mulch volcano” traps moisture and invites rot. Keep mulch 2–4 inches away from the trunk, and never exceed 3 inches of depth.

Compacting the soil hard. Firm enough to remove air pockets is right; stomping it into pavement is wrong. Roots need oxygen as much as water.

Amending only the hole. If you’re planting several shrubs, Clemson recommends adding organic matter throughout the whole bed (keep it to 10–20% of total soil volume). Hole-only amendments in clay soil create a “bathtub” effect where roots circle instead of exploring.

Spacing deserves its own mention. Prairie Nursery recommends measuring center to center based on each shrub’s mature width, and Monrovia advises keeping foundation shrubs 3–4 feet away from the house. Cramped planting leads to constant pruning and disease pressure down the road.

If you’re planning a mixed bed and want compact varieties that stay manageable near foundations, our roundup of best short shrubs for landscaping covers proven choices that thrive with the planting method above.