How to Plant a Crepe Myrtle: Step-by-Step Instructions

Proper planting is the foundation for a healthy, long-lived crepe myrtle. While these trees are remarkably adaptable, giving them the best possible start sets them up for success. This step-by-step guide walks you through the entire planting process, from site selection to aftercare, ensuring your new tree thrives from day one.

Before You Begin: Timing and Tools

Best Planting Time

In Australia, the ideal planting window is autumn through early spring (March to September). Planting during cooler months gives roots time to establish before summer heat arrives. Avoid planting in the middle of summer unless absolutely necessary, as the stress on the plant is significantly higher.

Tools You'll Need

• Spade or shovel
• Garden fork
• Wheelbarrow or tarp for excess soil
• Measuring tape
• Hose or watering can
• Mulch (bark chips, wood chips, or straw)
• Compost or aged manure (optional but recommended)
• Stake and ties (for exposed or windy sites)

Step 1: Choose the Right Location

Site selection is crucial. Crepe myrtles need:

• Full sun: At least 6 hours of direct sunlight daily. More sun means more flowers.
• Good drainage: Avoid areas where water pools after rain.
• Adequate space: Consider the mature size and allow room for growth.
• Air circulation: Don't plant too close to walls or fences.

Step 2: Prepare the Planting Hole

The planting hole is more important than many gardeners realise. Follow these guidelines:

1. Width: Dig the hole 2-3 times wider than the root ball. Wide holes are more important than deep ones, as roots grow outward more than downward.
2. Depth: The hole should be the same depth as the root ball, or slightly shallower. The top of the root ball should sit level with or slightly above the surrounding soil.
3. Sides: Use a garden fork to roughen the sides of the hole. Smooth sides can create a barrier that roots struggle to penetrate.

Soil Improvement

If your soil is heavy clay or very sandy, mix some compost or aged manure with the excavated soil. Use about 20-30% organic matter to 70-80% native soil. Don't overdo it, as you want roots to eventually grow into the surrounding soil.

Step 3: Prepare the Tree

Before placing the tree in the hole:

1. Water thoroughly: Give the potted tree a deep soak an hour before planting. This helps the root ball hold together and reduces transplant shock.
2. Remove the pot: Carefully slide the tree from its container. If stuck, cut the pot away rather than pulling on the trunk.
3. Check the roots: Look for circling or girdling roots. If roots are wrapping around the root ball, use a sharp knife to make 3-4 vertical cuts through the outer layer. This encourages roots to grow outward.
4. Loosen matted roots: Gently tease out any densely matted roots at the bottom of the root ball.

Step 4: Plant the Tree

1. Position: Place the tree in the centre of the hole. Step back and check it's straight from multiple angles.
2. Check depth: The root flare (where trunk meets roots) should be visible at or slightly above ground level. Add or remove soil beneath the root ball as needed.
3. Backfill: Fill the hole halfway with your soil mix, firming gently as you go. Add water to settle the soil, then continue filling to ground level.
4. Create a watering basin: Build a low ridge of soil in a ring around the tree, just outside the root ball, to hold water.

Step 5: Water Deeply

Immediately after planting, water the tree thoroughly:

1. Fill the watering basin you created and let it drain completely.
2. Repeat 2-3 times to ensure water penetrates the entire root zone.
3. This deep soaking settles the soil around roots and eliminates air pockets.

Step 6: Apply Mulch

Mulching is essential for new plantings:

• Apply 5-10cm of organic mulch (bark chips, wood chips, or straw)
• Spread mulch in a ring from just outside the trunk to beyond the drip line
• Keep mulch at least 10cm away from the trunk to prevent bark rot
• Mulch conserves moisture, regulates soil temperature, and suppresses weeds

Step 7: Initial Care

First Week

Water every 2-3 days if no rain falls. Keep soil consistently moist but not waterlogged.

First Month

Water deeply twice weekly in warm weather, once weekly in cool weather. Monitor the tree for signs of stress.

First Summer

During hot weather, water deeply twice weekly. Don't fertilise in the first season; let the tree focus on root development.

Second Year and Beyond

Gradually reduce watering as roots establish. Begin fertilising in spring of the second year.

Common Planting Mistakes to Avoid

1. Planting too deep: Burying the root flare leads to rot and poor growth.
2. Hole too narrow: Roots need room to spread. Always dig wider than you think necessary.
3. Ignoring circling roots: These will eventually strangle the tree if not addressed at planting.
4. Over-amending soil: Too much compost in the planting hole can cause roots to stay put instead of spreading.
5. Underwatering initially: New trees need consistent moisture to establish.
6. Planting in summer: High stress makes establishment harder.

By following these steps, you'll give your crepe myrtle the best possible start. A well-planted tree establishes faster, grows stronger, and rewards you with beautiful flowers for decades to come.