Hydrangea
Hydrangea macrophylla
family
Hydrangeaceae
Difficulty factors: Temperature sensitive, Best started from transplants, High water requirements
duration
Perennial
growth habit
Shrub
why learn this plant?
Hydrangea teaches aesthetic garden design, deadheading techniques, and how to attract pollinators to your garden.
timeline
germination
7-14
days to maturity
365
growth stages
Germination/Establishment
1-2 weeks
Seeds swell and sprout, or transplants establish roots
Check in:
Look for first signs of green growth emerging from soil
Tasks:
- Keep soil consistently moist
- Maintain temperature
- Protect from strong wind
Watch for:
- Damping off from overwatering
- Poor germination from old seed
Seedling
2-4 weeks
True leaves develop, stem strengthens
Check in:
Count true leaves — ready for transplant at 2-4 sets
Tasks:
- Thin seedlings if direct-sown
- Begin light fertilizing
- Harden off if started indoors
Watch for:
- Leggy seedlings from insufficient light
- Transplant shock
Vegetative Growth
3-8 weeks
Rapid leaf and stem growth, plant fills out
Check in:
Plant should be growing visibly each week
Tasks:
- Regular watering
- Fertilize on schedule
- Add support if needed
- Watch for pests
Watch for:
- Nutrient deficiency (yellowing leaves)
- Pest damage
how to grow
starting method
transplant
sun requirements
Partial shade
spacing
36-60 inches" × "36-60 inches"
planting depth
Rootball depth
water needs
Frequency: Every 2-3 days
Amount: 1-2 inches per week
Method: Drip irrigation or soaker hose preferred. Water at base, avoid wetting leaves.
soil & fertilizer
Amend with compost. Preferred pH: 6.0-7.0. Soil type: Well-drained, fertile soil.
At planting: Balanced 10-10-10 or compost
During growth: Balanced fertilizer every 3-4 weeks every Every 2-4 weeks during growing season
zone timing guide
Best grown when temperatures are 60-80°F. Plant after last frost in spring.
Zone 3
Start indoors: April
Transplant: Late May-June
Short growing season, choose early varieties
Zone 4-5
Start indoors: March-April
Transplant: May-June
Direct sow: May
Zone 6-7
Start indoors: February-March
Transplant: April-May
Direct sow: April-May
Zone 8-9
Start indoors: January-February
Transplant: March-April
Direct sow: March
Zone 10+
Direct sow: February-March
Year-round growing possible
harvest guide
Visual cue
Mature size reached, typical color for variety. Harvest when hydrangea looks ready.
Feel
Firm but not hard. Should separate from plant easily.
Timing
Typically 365 days from planting
Storage
Store in cool location. Use within 1-2 weeks for best quality.
what can go wrong
Overwatering
Visual cue:
Yellowing lower leaves, mushy stems, mold on soil surface
Why it happens:
Too frequent watering without checking soil moisture
Prevention:
Check soil moisture before watering — stick finger 1 inch into soil
If it happens:
Allow soil to dry out between waterings. Improve drainage.
skill progression
ready to grow Hydrangea?
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