By Nancy Penrose
As we enter the second half of the year and summer temperatures start to rise, it’s the perfect time to take stock of your trees’ health and ensure they have what they need to thrive through the warmest months. Mid-year is a critical point in the tree care calendar—it’s when heat, drought, pests, and overgrowth can combine to stress your trees if they’re not properly cared for. Whether you’re a homeowner, landscaper, or gardening enthusiast, this checklist will help you give your trees the attention they need right now.
1. Inspect Trees for Signs of Stress or Damage
The first step in mid-year maintenance is a visual inspection of each tree. Look for:
- Wilting, curling, or yellowing leaves (may indicate water stress or nutrient deficiencies)
- Cracks or splits in the trunk
- Broken, dead, or diseased branches
- Signs of insect activity (sawdust, holes, or sticky residue)
- Fungal growth, especially near the roots or on the bark
Catching these signs early allows for timely intervention, which can save a tree from long-term damage or decline.
2. Water Deeply and Consistently
One of the most common mistakes during summer is improper watering. Mature trees typically require less frequent watering than lawns or flower beds, but when they do need water, it should go deep.
Best practices for summer watering:
- Water early in the morning or late in the evening to reduce evaporation.
- Use a soaker hose or drip system to deliver water slowly to the root zone.
- Aim for one deep watering per week for mature trees, more frequently for young or newly planted trees.
- Avoid shallow, daily watering—it encourages roots to stay near the surface, making trees less drought-tolerant.
Remember that trees planted within the past two years are particularly vulnerable and may need more frequent attention.
3. Mulch to Retain Moisture and Regulate Soil Temperature
Mulching is one of the simplest yet most effective ways to protect your trees during hot summer months.
Apply a 2–4 inch layer of organic mulch (such as shredded bark, wood chips, or composted leaves) around the base of the tree, ideally extending out to the drip line. Keep the mulch a few inches away from the trunk to prevent rot and pest problems.
Benefits of mulching include:
- Reduced water loss from soil
- Lower soil temperatures
- Suppressed weed growth
- Improved soil structure over time
4. Check for Pest Activity
Warm weather is prime time for a wide range of tree pests, including aphids, scale, spider mites, and borers. Regular inspection is key to catching infestations early.
Look for:
- Leaf discoloration or curling
- Sticky sap (a sign of aphids or scale)
- Sawdust or frass around the base of the tree (indicates borers)
- Unusual growths or lesions on leaves or bark
If pests are detected, your local tree nursery can help you identify the best treatment—whether organic or chemical—for your specific tree species and your region.
5. Avoid Heavy Pruning During Peak Heat
While pruning is essential to tree health, mid-summer is generally not the ideal time for heavy pruning. Major cuts can stress the tree and expose sensitive areas to intense sun, pests, or disease.
That said, it’s still important to:
- Remove any dead, broken, or diseased limbs immediately
- Trim back small branches that pose a safety hazard
- Clean up any storm damage
Save major pruning or shaping for late fall or winter when trees are dormant, unless you’re working with a species that benefits from summer trimming (such as certain fruit trees).
6. Fertilize Only if Necessary
Many established trees do just fine without supplemental fertilizer, especially if you mulch regularly. However, signs like yellowing leaves, poor growth, or sparse foliage may indicate a nutrient deficiency.
Before applying fertilizer, consider doing a soil test to determine exactly what your tree needs. Over-fertilizing can do more harm than good, especially during the hot summer season.
7. Support Young or Leaning Trees
If you’ve planted new trees earlier this year, now is the time to check their stability. Windy summer storms and rapid growth can sometimes cause young trees to lean or uproot slightly.
Ensure stakes are still properly supporting the tree without restricting growth. Ties should be secure but not tight, and staking should be removed after the first full growing season unless the tree still shows signs of instability.
8. Clean Up Around the Base
Keep the area around your tree free of grass, weeds, and debris. This not only reduces competition for water and nutrients, but also helps prevent pest infestations and fungal problems.
Avoid piling grass clippings or leaves directly around the trunk, as this can retain moisture and create a breeding ground for rot and insects.
Final Thoughts
Caring for your trees in midsummer isn’t just about getting them through the heat—it’s about setting them up for long-term health and beauty. With a few proactive steps, you can keep your landscape thriving and resilient, even during the toughest part of the year.
If you’re unsure about any aspect of tree care, or if a tree seems to be struggling despite your efforts, don’t hesitate to consult your local tree nursery or a certified arborist. They can help you make informed decisions and preserve the value and vitality of your trees.
Need advice on what to plant or how to care for your trees? Visit our nursery or give us a call—we’re happy to help you grow with confidence.
Nancy Penrose is the owner of Big Trees Inc., located in Snohomish, WA in the Seattle area. The company is one of the largest tree nurseries in the Seattle area with over 120,000 trees available in over 300 varieties. They not only deliver young trees, but also mature trees in a wide range of sizes. Some types of trees available include spring flowering, deciduous, evergreen, and privacy trees. The company also does tree transplanting including large trees. Their blog can be seen at https://bigtreesupply.com/blog/ or http://arboristblog.com/. They can be reached at 360-563-2700.
Big Trees Inc.
10928 Springhetti Rd
Snohomish, WA 98296
360-563-2700
