You've properly planted your shrub. You water it diligently, and prune and fertilize as needed. However, since shrubs are living, they can still become sickly despite your best efforts. Here are some things to look for when assessing whether you have a healthy shrub:
No Dead or Broken Branches
Prune away dead and broken branches as soon as you see them, as these are a common way for insects and diseases to enter the shrub. Test for dead branches by scraping the branch with your thumbnail. Living branches will show green underneath. You can also test branches by gently bending them. Living branches will be supple and bend easily. If the branch is dead, it will snap.
No Bare Patches
If you have an evergreen shrub, watch for sections without leaves year-round. Otherwise, wait until the leaves have appeared on your deciduous shrubs in the spring. Common causes of bare patches include:
- Improper pruning practices
- Animals eating the leaves
- Insects and diseases
- Nutrients and water not reaching those branches
- Pesticide damage
Evidence of Yearly Growth
Shrubs produce new growth yearly on both their base and their branches. If the shrub is not producing new branches and buds, you may have a problem.
Proper Leaf Color, Shape, and Size
Watch the leaves on your shrubs carefully. Make sure they are the right color for the season you are in. Unless the shrub naturally has yellow or variegated leaves, be especially wary if they turn yellow. They should not be stunted or irregularly-shaped. These all can be signs of nutrient deficiencies, insect damage, watering problems, pesticide damage, and diseases.
No Wilting
When a plant is stressed, a common sign is wilting. Some of the causes include:
- Lack of water
- Over-watering
- Too much or too little sun
- Over-fertilized
- Diseases
- Root-bound
No Signs of Insects or Diseases
If you are properly caring for your shrub and still have problems, it is likely caused by insects or diseases. Some warning signs to look for are:
- Insects visible on shrub
- Growths on branches
- Distortions in leaf size, color or shape
- Holes in bark, branches, or leaves
- Oozing sap
- Lack of fruit
- Slowing in growth rate
- Wilting
