Leaf Issues

Yellowing Leaves

Symptoms: Leaves turn yellow starting from the bottom or throughout the plant, may progress to leaf drop Common Causes:

• Overwatering causing root stress and poor oxygen availability
• Nutrient deficiency, particularly nitrogen or iron chlorosis
• Natural aging of older leaves, especially in fall

Solutions:

• Check soil moisture and adjust watering schedule - allow top 2 inches to dry between waterings
• Apply balanced fertilizer in spring or chelated iron for chlorosis
• Remove yellowed leaves to redirect energy to healthy growth

Prevention: Maintain consistent watering schedule, ensure proper drainage, and fertilize annually in early spring

Brown/Crispy Leaves

Symptoms: Leaf edges turn brown and crispy, progressing inward; leaves may curl or become brittle Common Causes:

• Underwatering or drought stress during hot weather
• Excessive fertilizer causing salt burn
• Wind damage or extreme temperature fluctuations

Solutions:

• Deep water weekly during dry periods, mulch to retain moisture
• Flush soil with water to remove excess salts if over-fertilized
• Provide windbreak or relocate if exposed to harsh conditions

Prevention: Apply 2-3 inch mulch layer, water deeply rather than frequently, avoid fertilizing during drought

Drooping/Wilting

Symptoms: Branches and leaves droop despite adequate soil moisture, may recover in evening Common Causes:

• Heat stress during afternoon sun exposure
• Root damage from overwatering or root rot
• Transplant shock after planting or moving

Solutions:

• Provide temporary shade during hottest part of day
• Check roots for rot - trim damaged roots and replant in well-draining soil
• Water deeply and maintain consistent moisture for transplants

Prevention: Plant in location with morning sun and afternoon shade in hot climates, improve soil drainage

Leaf Drop

Symptoms: Sudden or gradual loss of leaves, may affect entire branches Common Causes:

• Seasonal change in fall (normal for deciduous Weigela)
• Water stress from drought or overwatering
• Pest infestation or disease infection

Solutions:

• Determine if seasonal (no action needed) or stress-related
• Adjust watering based on soil moisture levels
• Inspect for pests or disease and treat accordingly

Prevention: Maintain consistent care routine, monitor for early signs of stress or pest problems

Growth Issues

Stunted Growth

Symptoms: Plant fails to reach expected size, minimal new growth each season Common Causes:

• Poor soil nutrition or compacted soil
• Inadequate sunlight (less than 6 hours daily)
• Root competition from nearby plants or trees

Solutions:

• Amend soil with compost and apply slow-release fertilizer
• Prune surrounding vegetation to increase light exposure
• Consider transplanting to better location with more space

Prevention: Plant in full sun to partial shade, prepare planting hole with amended soil, space properly

Leggy/Stretching Growth

Symptoms: Long, weak stems with sparse foliage, poor flowering Common Causes:

• Insufficient light causing plant to stretch toward sun
• Lack of pruning allowing old wood to dominate
• Over-fertilization promoting excessive vegetative growth

Solutions:

• Relocate to sunnier spot or prune overhead shade
• Prune immediately after flowering to encourage bushy growth
• Reduce nitrogen fertilizer and switch to balanced formula

Prevention: Annual pruning after bloom, proper site selection, moderate fertilization

Pest Problems

Aphids

Identification: Small, soft-bodied insects clustering on new growth and flower buds Damage Signs: Curled leaves, sticky honeydew, sooty mold growth Treatment:

• Spray with strong water stream to dislodge aphids
• Apply insecticidal soap or neem oil weekly
• Release ladybugs or lacewings for biological control Prevention: Encourage beneficial insects, avoid over-fertilizing with nitrogen, monitor new growth regularly

Japanese Beetles

Identification: Metallic green beetles with copper-colored wing covers, 1/2 inch long Damage Signs: Skeletonized leaves with only veins remaining, damaged flowers Treatment:

• Hand-pick beetles in early morning when sluggish
• Apply pyrethrin-based insecticide if severe
• Use beetle traps away from plants to divert them Prevention: Apply milky spore to lawn for grub control, use row covers during peak season

Spider Mites

Identification: Tiny spider-like pests visible with magnification, fine webbing on leaves Damage Signs: Stippled, bronzed leaves, premature leaf drop Treatment:

• Spray undersides of leaves with water regularly
• Apply miticide or horticultural oil
• Remove heavily infested branches Prevention: Maintain adequate humidity, avoid dusty conditions, regular monitoring

Disease Issues

Powdery Mildew

Symptoms: White, powdery coating on leaves and stems, distorted growth Causes: High humidity, poor air circulation, overhead watering Treatment:

• Apply fungicide containing sulfur or potassium bicarbonate
• Remove affected leaves and dispose in trash
• Improve air circulation by thinning branches Prevention: Water at soil level, space plants properly, choose resistant varieties

Anthracnose

Symptoms: Dark, sunken spots on leaves and stems, leaf blight Causes: Fungal infection favored by wet, cool conditions Treatment:

• Prune out infected branches during dry weather
• Apply copper-based fungicide in early spring
• Rake and destroy fallen leaves Prevention: Avoid overhead watering, ensure good drainage, maintain plant vigor

Root Problems

Root Rot

Symptoms: Yellowing leaves, wilting despite moist soil, branch dieback Identification: Roots appear brown or black and mushy when examined Treatment:

• Remove plant and trim away all diseased roots
• Replant in fresh, well-draining soil or raised bed
• Apply fungicide drench if replanting in same area Prevention: Plant in well-draining soil, avoid overwatering, ensure proper planting depth

Root Bound

Symptoms: Slow growth, quick wilting, roots circling container or growing above soil Identification: Dense mat of roots visible when removed from container Treatment:

• Transplant to larger container or ground
• Score or tease apart circling roots before replanting
• Water thoroughly after transplanting Prevention: Repot container plants every 2-3 years, choose appropriate container size

Environmental Stress

Temperature Shock

Symptoms: Sudden leaf drop, wilting, branch dieback after temperature extremes Causes: Late spring frost, extreme heat waves, rapid temperature changes Treatment: Prune damaged growth after danger passes, provide extra water during recovery Prevention: Choose cold-hardy varieties for your zone, protect from late frost, mulch roots

Humidity Issues

Low Humidity Symptoms: Crispy leaf edges, increased spider mite susceptibility High Humidity Symptoms: Fungal disease proliferation, poor air circulation issues Solutions: Group plants together for higher humidity, improve drainage and air flow for excess humidity Prevention: Site appropriately based on local climate conditions

Light Stress

Too Much Light: Bleached leaves, sunscald on stems, excessive wilting Too Little Light: Poor flowering, leggy growth, weak stems Solutions: Relocate or provide shade/sun as needed, gradual acclimation to new conditions Prevention: Research light requirements before planting, observe site throughout seasons

Quick Diagnostic Guide

Emergency Symptoms

When to Seek Help

• Disease spreads despite treatment efforts
• Plant shows no improvement after 3-4 weeks of corrective care
• Unsure of pest or disease identification

Prevention Checklist

• [ ] Plant in well-draining soil with proper spacing
• [ ] Water deeply but infrequently to encourage deep roots
• [ ] Mulch annually to conserve moisture and regulate temperature
• [ ] Prune after flowering to maintain shape and air circulation
• [ ] Fertilize once in early spring with balanced fertilizer
• [ ] Monitor regularly for early pest or disease detection

Recovery Timeline

Week 1: Implement immediate fixes (watering, pest control, pruning damage) Week 2-3: Monitor for improvement, continue treatments, new growth may appear Month 1+: Full recovery expected for most issues, flowering may resume next season

Remember: Most Weigela 'Black and White' problems are preventable with proper care. When in doubt, adjust watering first, then light conditions.