Why are my new shrubs dying after planting?

New shrubs usually die for one of a handful of reasons, and most of them come back to water. The root ball a shrub arrives with is small, its roots have not grown into your soil yet, and it can dry out in a day or two even when the bed looks damp. Or the opposite happens: the hole holds water and the roots drown. After those come planting and site problems you can usually see if you look closely at the base of the plant.

If your plants are drooping in the first few days rather than browning over weeks, start with why new plants wilt after planting. This page covers the slower decline: browning leaves, leaf drop and dieback over the first season.

1. The root ball dried out

This is the most common cause. A plant that is not established relies solely on the relatively limited water supply in its root ball,^[1] and the potting soil of most container-grown shrubs holds only a one- to two-day supply of available water.^[2] Virginia Tech expects watering two to three times a week in summer when there is no rain.^[2] B&B shrubs usually need only weekly watering, because the mineral soil around their roots holds more water.^[2]

Timing matters too. Shrubs planted in spring may not have rooted into the surrounding soil by summer,^[2] so a spring planting that looked fine in May can brown in the first July heat. Check the root ball itself, beside the stem. Virginia Tech's tree guidance puts it simply: if the soil near the trunk is dry, the trees need water.^[3] See how often to water new plants for a schedule.

2. The roots are sitting in water

Wet soils can reduce plant growth and survival,^[2] and from the top a drowning shrub looks much like a dry one. "Waterlogging of the root zone also results in oxygen deficiency, leading to a halt in root growth and metabolism, death of the roots, and wilt."^[1]

Suspect this in heavy clay, at the bottom of a slope, or where you water daily. Common causes include planting near a downspout and digging a hole too deep or filling it with gravel, which collects water and drowns roots.^[4] Daily watering of a slow-draining bed adds to it, and any plant can be killed by overwatering.^[5] Before replanting, test the spot: fill a hole with water, and "If the water doesn't drain in 24 hours, plant elsewhere."^[2]

3. It was planted too deep or mulched too high

For shrubs, the top of the roots should be level or slightly above level with the surface of the ground.^[2] A shrub set low, or with soil and mulch heaped over the root ball, struggles for air. Also, overly deep mulch, or mulch piled against the stems, promotes shallow roots, disease and pest injury.^[2] Rake mulch back into an even layer that does not touch the stems.

4. The roots never left the pot shape

A root-bound shrub's roots form a solid mass that often circles the root ball,^[2] and if those roots were not cut or loosened at planting they may keep circling instead of growing out. A shrub that lifts out of the ground months later with its root ball intact is a sign of this.

Leftovers do damage too. Tags, wires and ropes left on stems can girdle and kill a shrub as it grows,^[2] and synthetic twine does not readily degrade.^[2] Check B&B shrubs for twine tied around the stems.

5. The wrong shrub for the spot

Some shrubs fail because the site does not suit them. Mountain laurel and azaleas, for example, have very fine roots that only push into loose soil, so they survive poorly in clay^[2] unless the backfill is amended. Light matters as well: "A rapid change from low light to high light intensity, or vice versa, can cause yellowing of leaves, reduced growth, and leaf drop or death."^[1] A shade-lover in afternoon sun, or a sun-lover under a tree, may never thrive. Good landscape planning prevents most of these.

6. Fertilizer, mowers and weather

• Too much fertilizer. Fertilizers are salts that may be damaging to plants during dry periods,^[2] and most nursery-grown shrubs were well fertilized in production and may not need fertilizer at planting.^[2]
• Mower and trimmer damage. Damage to the base of a tree trunk is often caused by weed trimmer or mower damage,^[1] and the same happens to shrub stems. A 2 to 3 inch layer of mulch kept off the stems also protects the shrub from mower and string trimmer injury.^[2]
• Winter damage. Late-summer pruning can push a flush of new shoots that may not harden off before winter.^[2]

7. Pests and disease

These are less common in new plantings but real. Look at the pattern. Damage to all different types of plants in a particular spot can indicate nonliving factors.^[1] Damage to a few species of plants or only to plants of the same species can indicate living factors.^[1] If an established area shows abnormal growth or discoloration, take a soil sample right away,^[6] and bring photos and a sample to your local Extension office for a diagnosis.

Stop and call a pro if

• Water stands in the bed after rain or runs toward the house; the site needs drainage work before more planting.
• Several kinds of shrubs are failing in the same area despite correct watering.
• Large B&B shrubs were planted too deep and need lifting and resetting, which is heavy work.
• A landscaper installed the shrubs and they are still within the replacement period.

Browse more lawn and landscaping answers, compare landscape design and installation services, or find lawn and landscaping businesses around Blacksburg. To have failed shrubs replaced or a bed replanted, describe the job once and local businesses quote it.