When to plant Geraniums in Delmar,
Delmar's 218-day season only supports one Geraniums planting per year. Sow between April 3 and April 17 for the best chance at full maturity before November 7.
When to Plant Geraniums in Delmar, DE
Your June gardening checklist
Each item below is timed to Delmar, DE's frost dates and soil temperatures. Skip nothing, stress about nothing.
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Start geraniums indoors
Label every cell. You will absolutely forget which is which otherwise.
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Bring in the geraniums
Check every 1–2 days. Many of these get tough or go to seed if you wait too long.
Coming up in July — start thinking about
- First harvests: geraniums
Geraniums (Pelargonium × hortorum) are tender perennials grown as warm-season annuals throughout North America. Prized for their bold flower clusters, long bloom period, and tolerance of summer heat when planted in well-drained soil, they anchor window boxes, containers, and bed borders from late spring until hard frost. Zones 9b–11b can overwinter plants in the ground.
Delmar, Delaware is in USDA Zone 7b. The average last spring frost is April 3 and the first fall frost is November 7, giving you a growing season of approximately 218 days.
At an elevation of 1,090 feet, Sussex County receives approximately 46 inches of rainfall annually with predominantly silt loam soil. Summer highs average 88°F, providing good warmth for Geraniums during the growing season.
Delmar Soil Profile
Soil Type
Silt Loam
Soil pH
5.6-6.5
Drainage
Well Drained
Geraniums 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 Delmar
How your county's soil matches Geraniums's growing requirements.
Soil pH
Your soil pH (5.6–6.5) overlaps with Geraniums's range (6.0–7.0), though not a perfect match.
Soil Texture
The silt loam soil in Sussex County is excellent for Geraniums — good drainage, moisture retention, and nutrient holding capacity.
Organic Matter
Organic matter is moderate (2.8%). Annual compost additions will help Geraniums.
How to Plant Geraniums
Succession Planting Geraniums
Sow every 8 weeks. Last sowing by Jul 30 to harvest before frost.
Geraniums Water Budget
Monthly Watering Guide for Geraniums
Geraniums needs approximately 1 inches of water per week (4.3" per month). Here's how your county's rainfall compares month by month.
| Month | Geraniums Needs | Rainfall | You Supplement | Action |
|---|---|---|---|---|
| Jan | — | 3.5" | 0" | ❄️ Dormant |
| Feb | — | 3.5" | 0" | ❄️ Dormant |
| Mar | — | 3.9" | 0" | ❄️ Dormant |
| Apr | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| May | 4.3" | 4.5" | 0" | ✅ Rainfall sufficient |
| Jun | 4.3" | 3.7" | 0.6" | 💧 Light watering |
| Jul | 4.3" | 5.3" | 0" | ✅ Rainfall sufficient |
| Aug | 4.3" | 4.1" | 0.2" | 💧 Light watering |
| Sep | 4.3" | 3.9" | 0.4" | 💧 Light watering |
| Oct | 4.3" | 3.4" | 0.9" | 💧 Light watering |
| Nov | 4.3" | 3.2" | 1.1" | 💧 Light watering |
| Dec | — | 3.3" | 0" | ❄️ Dormant |
Water needs are for active growing months only (Apr–Nov in Sussex County). Supplement amounts are based on average rainfall — actual needs vary with temperature, soil, and mulching.
Geraniums 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.
Geraniums Planting Timeline — Delmar, DE
Geraniums Planting Calendar
| Activity | When | Date Range |
|---|---|---|
| Start Indoors | January 23 | Jan 23 – Feb 6 |
| Transplant Outdoors | April 3 | Apr 3 – Apr 17 |
| Bloom | June 12 | Jun 12 – Oct 16 |
Plant 0.1" deep · 12" apart · Rows 14" apart
Month-by-Month Timeline
| Month | Activities |
|---|---|
| January | Start Indoors |
| February | Start Indoors |
| March | — |
| April | Transplant Outdoors |
| May | — |
| June | Bloom |
| July | Bloom |
| August | Bloom |
| September | Bloom |
| October | Bloom |
| November | — |
| December | — |
Growing Conditions
☀️ Sun
Full Sun (6-8+ hours)
💧 Water
1"/week · Only during dry spells
📅 Days to Maturity
70–100 days
🧪 Soil pH
Needs 6–7 · Your soil: acceptable
🗺️ USDA Zone
Zone 7b
📆 Growing Season
218 days in Sussex County
Growing Tips for Geraniums in Delmar
Direct sow Geraniums outdoors after April 03 in Sussex County when soil has warmed and frost danger has passed.
General growing tips
Start seeds indoors 10–12 weeks before last frost — germination is slow and erratic without bottom heat (70–75°F). Transplant after frost danger passes. Geraniums rarely direct-sown; cuttings or transplants are the standard. Deadhead spent umbels weekly to maintain continuous bloom. Let soil dry slightly between waterings to prevent root rot. In zones 10–11 plants may be left in ground year-round or overwintered as houseplants.
Companion Planting
Good Companions
Check more plant combinations with our Companion Planting Checker →
Geraniums in Other Locations
When should I plant Geraniums in Delmar, ?
In Delmar, , plant Geraniums after the last frost (around April 3) and before the first frost (around November 7). Best results when soil holds above 50°F.
What growing zone is Delmar, for Geraniums?
Delmar sits in USDA Zone 7b. Geraniums grows reliably in zones 2a through 11b, so it's a good fit here.
Can Geraniums grow in Delmar's climate?
Yes — Geraniums grows well in Delmar's temperate climate. Delmar averages a 218-day frost-free season, with last frost around April 3 and first frost around November 7.
Your Sussex County Garden Planner — Free
A 22-page printable planner built for Sussex County (Zone 7b). Planting dates, a month-by-month schedule, harvest log, seed inventory, and succession charts — all dialed in for your exact growing season.