Knowing when to plant nasturtium seeds in Zone 7 is the key to a vibrant, long-lasting display of these easy-care flowers. Getting the timing right in spring protects the tender seedlings from late frosts and sets them up for quick growth as the weather warms.
Nasturtiums are a gardener’s favorite for good reason. They grow quickly, their peppery leaves and flowers are edible, and they can help deter pests from other plants. In Zone 7, where winters are moderate but frosts are still a threat, spring planting is your best bet for success. Let’s look at how to pinpoint the perfect planting window.
When To Plant Nasturtium Seeds Zone 7
The optimal time to plant nasturtium seeds directly in your Zone 7 garden is after the last average spring frost date. For most Zone 7 areas, this falls between mid-April and early May. Soil temperature is a more precise guide; aim for when the soil has warmed to at least 55°F (13°C), with 65°F (18°C) being ideal for faster germination.
Understanding Your Zone 7 Frost Dates
Zone 7 has a relatively long growing season, typically around 180 days. However, the last frost date can vary. It’s crucial to know your local dates.
- Average Last Frost: Generally between April 15th and April 30th.
- Average First Frost (Fall): Usually between October 15th and October 30th.
Use these dates as a guideline, but always check a trusted local weather forecast for the current year’s conditions. A surprise late frost can damage or kill young nasturtium seedlings.
Why Timing Matters for Nasturtiums
Nasturtium seeds are tender and will not germinate well in cold, wet soil. Planting to early can cause the seeds to rot. Even if they sprout, a light frost can wipe out young plants. Waiting for warm soil ensures a strong, healthy start.
Conversely, planting to late in the heat of summer can stress the plants. Nasturtiums prefer the cooler days of spring and fall. A spring planting gives them time to establish before summer’s peak heat, leading to better flowering.
Two Methods: Direct Sow vs. Starting Indoors
You have two main options for planting nasturtiums in Zone 7.
1. Direct Sowing (Recommended)
Nasturtiums have sensitive roots and transplant poorly. Direct sowing is often the easiest and most succesful method.
- Wait until 1-2 weeks after your last frost date.
- Choose a sunny location (6+ hours of sun) with well-draining soil. Poor soil actually produces more flowers!
- Soak seeds in water for 8-12 hours before planting to soften the hard outer coat.
- Plant seeds 1/2 inch deep and 10-12 inches apart.
- Water gently and keep the soil moist until germination, which takes 7-10 days in warm soil.
2. Starting Seeds Indoors (For a Head Start)
If you want earlier blooms, you can start seeds indoors. Use biodegradable pots to avoid disturbing roots during transplant.
- Start seeds indoors 3-4 weeks before your last expected frost.
- Plant one seed per pot, about 1/2 inch deep.
- Place in a sunny window or under a grow light.
- Transplant the entire pot into the garden after all danger of frost has passed, handling the roots with care.
Step-by-Step Planting Guide for Zone 7
Follow these steps for a foolproof nasturtium patch.
Step 1: Site Selection & Soil Prep
Nasturtiums thrive in full sun but will tolerate light afternoon shade in hot summer areas. They are not picky about soil fertility. In fact, rich soil leads to lots of leaves and fewer flowers. Avoid adding fertilizer or compost to the planting area for the best bloom production.
Step 2: Planting Your Seeds
After your frost date has passed and the soil is workable, it’s time to plant. Create small holes or a shallow trench. Place the pre-soaked seeds and cover them lightly with soil. Good spacing prevents mildew and promotes air circulation.
Step 3: Watering & Early Care
Water the planted area thoroughly but gently. Keep the soil consistently moist (not soggy) until you see sprouts. Once the plants are a few inches tall, you can reduce watering. Nasturtiums are somewhat drought-tolerant and prefer slightly drier conditions.
Step 4: Ongoing Maintenance
- Watering: Water deeply but infrequently once established. Let the soil dry out between waterings.
- Feeding: Do not fertilize. This encourages foliage over flowers.
- Pests: Aphids can be a problem. A strong spray of water from the hose usually knocks them off.
- Harvesting: You can pick leaves and flowers anytime for salads. Regular picking encourages more growth.
Can You Plant Nasturtiums in Fall in Zone 7?
Yes! Nasturtiums can also be planted in late summer for a fall display. Aim to plant seeds about 8-10 weeks before your first average fall frost. This gives them time to mature and flower in the cooler autumn weather, which they often prefer over summer heat.
Common Problems and Solutions
Even easy plants can have issues. Here’s what to watch for.
- No Flowers, All Leaves: This is almost always caused by soil that is too rich or too much nitrogen. Remember, poor soil is best for blooms.
- Yellowing Leaves: Often a sign of overwatering. Let the soil dry out more.
- Powdery Mildew: Appears as white powder on leaves. Improve air circulation, avoid overhead watering, and remove affected leaves.
- Seeds Not Sprouting: Usually means the soil was too cold or wet. Wait for warmer conditions and try soaking seeds first next time.
FAQ: Planting Nasturtiums in Zone 7
What month do you plant nasturtium seeds in Zone 7?
The prime planting month is typically April. For a more precise date, target the period from April 15th to May 1st, adjusting based on your local frost forecast and soil warmth.
Is it too late to plant nasturtium seeds in June?
In Zone 7, June planting is possible, but the plants may struggle with the summer heat. They will perform better if planted for a fall harvest. Provide some afternoon shade and consistent moisture if planting in early summer.
Should I soak nasturtium seeds before planting?
Yes, soaking nasturtium seeds for 8-12 hours before planting is highly recommended. It softens their hard outer shell and significantly speeds up germination, giving you sprouts days earlier.
Do nasturtiums come back every year in Zone 7?
Nasturtiums are annuals in Zone 7, meaning they won’t survive the winter freeze. However, they often self-seed readily. If you let the last flowers go to seed, you may find new volunteer plants popping up in the same spot next spring.
Can nasturtiums grow in partial shade?
They can grow in partial shade, especially in the hotter parts of Zone 7. But flowering will be reduced. For the most abundant blooms, aim for at least 6 hours of direct sunlight daily.
By following these guidelines for when to plant nasturtium seeds in Zone 7, you’ll enjoy a season filled with bright, cheerful flowers and tasty edible garnishes. Their easy-going nature makes them perfect for new gardeners and experinced ones alike. Just remember the golden rules: wait for warm soil, avoid rich earth, and don’t overwater. Your garden will soon be bursting with color.