Viburnum care guide: when & how to prune, fertilize and spray

When: 3–8 weeks before the last spring frost.

• zones 3–5: about Mar 15 – Apr 19
• zones 6–7: about Feb 18 – Mar 25
• zones 8–10: about Dec 31 – Feb 4

Destroying the overwintering eggs is the easiest way to stop the beetles.

1. Look on the undersides of this year's twigs for rows of small brown bumps.
2. Clip off and destroy any infested twigs.

When: 4–8 weeks after the last spring frost.

• zones 3–5: about Jun 7 – Jul 5
• zones 6–7: about May 13 – Jun 10
• zones 8–10: about Mar 25 – Apr 22

This shrub sets next year's flower buds over the summer. Pruning within a few weeks after the flowers fade gives the most blooms next year. Prune later and you cut off the buds.

1. Wait until the last flowers have faded.
2. Remove dead, damaged and crossing branches first.
3. Renewal-prune: cut one-third of the oldest, thickest stems right down to the ground. Over three years this replaces the whole shrub with vigorous young wood.
4. Shorten overly long stems to an outward-facing bud or side branch to shape the shrub. Avoid shearing it into a ball.
5. If you want berries for birds, leave some faded flower clusters in place.

Tools: Bypass pruners, Loppers

When: from 1 week before to 3 weeks after the last spring frost.

• zones 3–5: about May 3–31
• zones 6–7: about Apr 8 – May 6
• zones 8–10: about Feb 18 – Mar 18

A single spring feeding as growth starts covers most shrubs for the year.

1. Scatter fertilizer at the label rate from near the stems out past the drip line, where the feeder roots are.
2. Water it in thoroughly.

What to use: 🌿 Balanced organic granular fertilizer (e.g. Espoma Plant-tone 5-3-3) · Slow-release balanced fertilizer (e.g. Osmocote Smart-Release 14-14-14)

When: 2–6 weeks after the last spring frost.

• zones 3–5: about May 24 – Jun 21
• zones 6–7: about Apr 29 – May 27
• zones 8–10: about Mar 11 – Apr 8

Mulch keeps roots cool and moist, suppresses weeds and slowly feeds the soil. Applying it after the soil warms lets roots wake up first.

1. Spread 2–3 in (5–7 cm) of mulch over the root zone.
2. Keep mulch 2–3 in (5–7 cm) away from stems and trunks. Mulch piled against bark invites rot and rodents.
3. Don't go deeper than 3 in (7 cm) in total. Too much mulch suffocates roots.

What to use: 🌿 Shredded hardwood or pine bark mulch