10 Best Practices for Long-Term Oak Tree Health

Here’s what decades of experience and university research agree are the absolute best things you can do for your oak trees—whether they’re red, white, pin, bur, or any other species.

1. Prune ONLY during dormancy (November – March). This is non-negotiable if you want to avoid oak wilt. No exceptions for “just a small branch.” The highest-risk period in Michigan for oak wilt infection is April 15 - July 15.

2. Hire an ISA Certified Arborist. Proper pruning cuts matter. Bad cuts invite decay. Look for “ISA Certified Arborist” or “Tree Care Industry Association Accredited” companies.

3. Never top or lion’s-tail your oaks. Topping (cutting main branches back to stubs) is tree abuse. Lion’s-tailing (removing all interior branches, leaving puffs only on the ends) creates a weak branch structure that snaps in storms. Both practices shorten the tree’s life.

4. Mulch correctly – The #1 thing most people get wrong:

• 2–4 inches deep ring of wood chips or shredded bark
• Extend to the dripline if possible (that’s where the feeder roots are)
• Keep mulch 4–6 inches away from the trunk - no “mulch volcanoes”
• Replenish every 2–3 years. Mulch is the closest thing to a miracle for oaks: cooler roots, better moisture, weed suppression, and slow-release nutrients.

5. Water new & young oaks deeply but Infrequently. Newly planted oaks (under 5–7 years) need roughly 10 - 15 gallons once or twice a week during dry spells for the first two summers. Slow, deep watering beats frequent shallow sprinkles. Mature oaks are drought-tough, but in extreme drought years even they appreciate an occasional deep soaking.

6. Fertilize when needed. Healthy oaks in decent soil rarely need fertilizer. Over-fertilizing pushes weak, succulent growth that insect pests love. Get a soil test first. If you do fertilize, use slow-release, low-nitrogen formulas in late fall or early spring.

7. Protect the root zone:

• No parking cars or storing materials under the canopy
• No trenching or digging for irrigation, pools, patios, etc., without root barriers or arborist supervision
• Avoid soil grade changes - adding even 2 inches of soil over roots can kill an oak in a few years

8. Watch for these red flags & act fast:

• Sudden leaf drop or browning in summer → possible oak wilt 
• Mushrooms at the base or wet spots on trunk → root or butt rot
• Vertical cracks or seams in bark → possible lightning or frost damage
• Heavy lean or large dead branches → structural issue

9. Plant the right tree in the right place. A mature bur oak gets 70–80 ft tall and wide. A pin oak wants acidic soil. Match species to your soil, space, and zone to avoid problems 30 years from now.

10. Love them for generations. A well-cared-for oak can easily live 200 - 400+ years. Everything you do (or don’t do) today affects your kids and grandkids.

Follow these ten practices and your oaks will reward you with decades - or centuries - of shade, beauty, and wildlife habitat. Need help putting any of this into action? Send us a message or give us a call today at 800-724-6680 – it’s the best investment you’ll ever make in your trees.