When to plant Hydrangeas in Union County County,
In Union County County, Hydrangeas is a spring-only crop. Plant February 15–March 1 once soil hits 50°F.
When to Plant Hydrangeas in Union County, FL
Top priorities for Union County, Florida gardeners in June
Here's what deserves your attention in Union County, Florida this month. Everything below is tailored to Zone 9a and timed around your local frost dates.
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Pick hydrangeas
Morning harvests are best — cooler temperatures mean crisper produce and longer fridge life.
To set up a strong July, finish these tasks
- First harvests: hydrangeas
Hydrangeas (Hydrangea spp.) are among the most spectacular summer-blooming shrubs, with large mophead, lacecap, or panicle flower clusters lasting weeks in the garden and drying beautifully for arrangements. Native to Asia and North America alike, the genus spans several garden species with different hardiness and blooming habits. Panicle hydrangeas (H. paniculata, e.g., Limelight) are the most cold-hardy (Zone 3) and most reliable bloomers; smooth hydrangeas (H. arborescens, e.g., Annabelle) are equally tough. Bigleaf hydrangeas (H. macrophylla) are prized for blue/pink color-shifting blooms but require reliable snow cover or winter protection in Zones 5–6. Flower color in macrophylla types is determined by soil pH (acidic = blue, alkaline = pink).
Union County, Florida is in USDA Zone 9a. The average last spring frost is March 1 and the first fall frost is November 27, giving you a growing season of approximately 271 days.
At an elevation of 360 feet, Union County receives approximately 60.6 inches of rainfall annually with predominantly sand soil. Summer highs average 96°F, so Hydrangeas may need afternoon shade and extra watering during peak heat. Sandy soil warms quickly in spring — great for early planting — but Hydrangeas will need more frequent watering and organic matter to retain nutrients. Ample rainfall means less supplemental watering, but ensure good drainage to prevent Hydrangeas root diseases.
Union County Soil Profile
Soil Type
Sand
Soil pH
5.2-6
Drainage
Well Drained
Hydrangeas Planting Risk Windows
Percentages indicate frost risk at transplant. The 70% safe window means there is a 30% chance of frost after transplant — suitable for cold-hardy crops or gardeners with frost protection. The 90% safe window is best for tender plants.
Soil Compatibility in Union County
How your county's soil matches Hydrangeas's growing requirements.
Soil pH
Your soil pH (5.2–6.0) overlaps with Hydrangeas's range (5.5–6.5), though not a perfect match.
Soil Texture
Sandy soil in Union County warms quickly in spring but drains fast. Hydrangeas will need more frequent watering and regular compost additions to retain nutrients.
Drainage
Drainage is adequate for Hydrangeas.
Organic Matter
Organic matter is low (1.3%). Add 2-3 inches of compost before planting Hydrangeas.
How to Plant Hydrangeas
Hydrangeas Water Budget
Monthly Watering Guide for Hydrangeas
Hydrangeas needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Hydrangeas Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.1" | 0" | ❄️ Dormant |
| Feb | — | 2.7" | 0" | ❄️ Dormant |
| Mar | 4.3" | 3.5" | 0.8" | 💧 Light watering |
| Apr | 4.3" | 2.8" | 1.5" | 💧 Light watering |
| May | 4.3" | 4.4" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 8.1" | 0" | ✅ Rainfall sufficient |
| Jul | 4.3" | 10" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 9" | 0" | ✅ Rainfall sufficient |
| Sep | 4.3" | 7.2" | 0" | ✅ Rainfall sufficient |
| Oct | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Nov | 4.3" | 2.7" | 1.6" | 💧 Light watering |
| Dec | — | 2.5" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Mar–Nov in Union County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Hydrangeas Heat Requirements (GDD)
What are Growing Degree Days (GDD)?
Growing Degree Days measure the total warmth your plants receive during the growing season. Think of it as a "heat bank" — every day above 50°F deposits warmth that helps your plants grow.
Each plant needs a certain amount of accumulated heat to mature. If your county provides more GDD than the plant needs, it's a great fit. If it's close, you may want to choose faster-maturing varieties or start seeds indoors to get a head start.
Hydrangeas Planting Timeline — Union County, FL
Hydrangeas Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 4 | Jan 4 – Jan 18 |
| Transplant Outdoors | February 15 | Feb 15 – Mar 1 |
| Bloom | April 26 | Apr 26 – Aug 16 |
Plant 1" deep · 48" apart · Rows 60" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Transplant Outdoors |
| March | Transplant Outdoors |
| April | Bloom |
| May | Bloom |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | — |
| October | — |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Partial Shade (3-6 hours)
💧 Water
1"/week · 1-2 times/week
📅 Days to Maturity
90–150 days
🧪 Soil pH
Needs 5.5–6.5 · Your soil: acceptable
🗺️ USDA Zone
Zone 9a
📆 Growing Season
271 days in Union County
Growing Tips for Hydrangeas in Union County
Direct sow Hydrangeas outdoors after March 01 in Union County when soil has warmed and frost danger has passed.
Sandy soil in Union County dries quickly — mulch Hydrangeas with 2-3 inches of straw and water deeply 2-3 times per week rather than lightly every day.
With summer highs reaching 96°F in Union County, provide afternoon shade for Hydrangeas and water deeply in the morning.
General growing tips
Plant container-grown specimens in spring or fall, spacing at least 3–5 feet apart to allow for mature shrub spread. Most hydrangeas prefer morning sun with afternoon shade, especially in Zones 7+. Keep consistently moist — the name derives from the Greek for water vessel. Prune panicle and smooth types in late winter/early spring (they bloom on new wood). Prune bigleaf types only lightly after bloom; cutting stems in fall removes next year's buds. In Zone 5–6, protect bigleaf varieties with burlap or wire cages filled with leaves over winter. Fall planting (Zones 5+) gives excellent root establishment before summer heat. Year 2+ plants reach full size and bloom.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Hydrangeas in Other Locations
Frequently Asked Questions
When should I plant Hydrangeas in Union County, FL?
Union County is in Zone 9a with an average last frost of March 1. Plan your Hydrangeas planting based on this frost date — see the calendar above for exact timing.
What planting zone is Union County, FL?
Union County, Florida is in USDA Hardiness Zone 9a. The average last spring frost is March 1 and first fall frost is November 27.
When should I plant Hydrangeas in Union County County, ?
In Union County County, , plant Hydrangeas after the last frost (around March 1) and before the first frost (around November 27). Best results when soil holds above 50°F.
What growing zone is Union County County, for Hydrangeas?
Union County County sits in USDA Zone 9a. Hydrangeas grows reliably in zones 3a through 9a, so it's a good fit here.
Can Hydrangeas grow in Union County County's climate?
Yes — Hydrangeas grows well in Union County County's temperate climate. Union County County averages a 271-day frost-free season, with last frost around March 1 and first frost around November 27.
Your Union County Garden Planner — Free
A 22-page printable planner built for Union County (Zone 9a). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.