Double Down Bigleaf Hydrangea

Minimum temperature: Hardy to -10°F
USDA zone: 5–9
Light: Partial shade
Flower: Large double-petaled pink blooms
Bloom time: Summer
Pollination requirements: Not required
Growth habit: Rounded, dense

Can not ship to HI.

Planting Guide for Hydrangeas

1. Site Selection
Hydrangeas thrive in locations that receive morning sunlight and afternoon shade. They prefer areas with:
• Light Requirements: Partial sun to partial shade (about 4-6 hours of sunlight per day). Full shade can reduce blooms, while too much direct sunlight can scorch the leaves.
• Protection from Wind: Wind can dry out the plant and damage delicate flowers, so it's best to plant in a protected area.
• Good Drainage: Hydrangeas dislike wet feet, so avoid low-lying areas where water tends to pool. Ensure the soil drains well.

2. Spacing
• Spacing Needs: The spacing between hydrangeas depends on the type, but generally:
◦ Small varieties: 3–4 feet apart.
◦ Larger varieties (such as Panicle): 6–10 feet apart.
• Proper spacing ensures good air circulation, which helps prevent diseases.

3. Soil Type
Hydrangeas prefer:
• Moist, Well-drained Soil: Loamy soil that retains moisture but drains well is ideal.
• pH Sensitivity: Bigleaf hydrangeas (H. macrophylla) can change bloom color based on soil acidity.
◦ Acidic soil (pH below 6.0) produces blue flowers.
◦ Neutral to alkaline soil (pH 6.5 and above) produces pink or red flowers.
• Soil Amendments: Add organic matter like compost to improve the soil structure and nutrient content.

4. Planting Hydrangeas
1. Dig the Hole: Make a hole about twice the size of the root ball but no deeper than the root ball itself.
2. Amend the Soil: Mix compost or aged manure into the soil to improve drainage and fertility.
3. Planting Depth: Ensure the crown of the plant (where the stem meets the roots) is level with the surrounding soil.
4. Water Well: After planting, water deeply to help settle the soil and establish roots.

5. Watering
Hydrangeas need consistent moisture, particularly during the first few years:
• Water Deeply: Water about 1 inch per week, more during hot or dry weather. Deep watering encourages deep root growth.
• Mulching: Apply 2–3 inches of mulch around the base to retain moisture and keep the soil cool.

6. Fertilizing
• When to Fertilize: Fertilize in early spring before new growth starts and again in early summer if needed.
• Fertilizer Type: Use a balanced, slow-release fertilizer (10-10-10 or 12-4-8). Over-fertilizing can lead to excessive foliage growth at the expense of blooms.

7. Pruning
Pruning depends on the hydrangea variety:
• Bigleaf and Oakleaf Hydrangeas: Prune right after they bloom, as they bloom on old wood (last year’s growth).
Panicle and Smooth Hydrangeas: Prune in late winter or early spring, as they bloom on new wood (current year’s growth).
• Deadheading: Remove spent blooms to encourage more flowers.

8. Soil Acidity and Bloom Color
Bigleaf hydrangeas are especially known for their color-changing ability based on soil pH:
• To Achieve Blue Flowers: Lower the pH by adding soil acidifiers like sulfur or aluminum sulfate.
• To Achieve Pink Flowers: Raise the pH by adding lime to make the soil more alkaline.