If you’ve sown nasturtium seeds and are now peering at the soil, you might be wondering what do nasturtium seedlings look like. Identifying these young sprouts is key to ensuring you don’t mistake them for weeds. This guide will give you a clear picture of their first leaves, growth habits, and how to care for them from the moment they emerge.
Nasturtiums are wonderfully easy to grow from seed, but their seedling stage can be brief. Knowing what to look for gives you confidence in your garden. Let’s get you familiar with your new plants right from the start.
What Do Nasturtium Seedlings Look Like
The first signs of life from a nasturtium seed are the cotyledons. These are the seedling’s first “seed leaves,” and they look quite different from the mature plant’s foliage. After the cotyledons, the true leaves will appear, which is when the plant starts to look more familiar.
Here is a step-by-step breakdown of their early growth:
1. Day 1-3: Germination. The seed coat splits, and a pale root (radicle) emerges downward into the soil.
2. Day 4-10: Emergence. The stem (hypocotyl) pushes upward, arching through the soil. The two cotyledons are folded together as they break the surface.
3. Day 7-14: Cotyledon Stage. The cotyledons open fully. They are rounded, fleshy, and a bright, smooth green. They are nearly circular and lack any lobes or indentations.
4. Day 14-21: First True Leaves. The first set of true leaves grows from the center between the cotyledons. These are the iconic, shield-shaped nasturtium leaves, but smaller. They will have a central stem (petiole) and rounded lobes.
Key Features to Identify Nasturtium Seedlings
To be certain you’re looking at a nasturtium and not a weed, check for these specific characteristics.
The Cotyledons (Seed Leaves)
The initial pair of leaves are your biggest clue. They are:
* Nearly perfectly round and smooth-edged.
* Thick and succulent, almost like small, green disks.
* Bright green in color, with a matte or slightly glossy finish.
* They lack the prominent central vein and lobes of the true leaves.
The True Leaves
After the cotyledons, the next set of leaves will appear. These true leaves are:
* Shield-shaped (peltate). This means the leaf stem (petiole) attaches to the center of the leaf blade, not the edge.
* Rounded with gentle lobes. They look like small lily pads.
* A brighter, vibrant green than the cotyledons.
* Slightly waxy or matte on the surface, with veins radiating from the center.
Stem and Growth Habit
The young stem is another good identifier.
* It is juicy and succulent, not woody or fibrous.
* It may show a slight reddish or purplish tint, especially if grown in bright light.
* Trailing varieties will quickly start to sprawl, while bush types remain more compact.
Common Look-Alikes and How to Tell Them Apart
It’s easy to confuse seedlings, especially in mixed garden beds. Here are a few common ones and how to differentiate them.
* Weedy Spurge: Often sprouts in similar conditions. Spurge cotyledons are much smaller, narrower, and oval-shaped. Its stem exudes a milky sap when broken (nasturtium does not).
* Creeping Charlie (Ground Ivy): Its first true leaves are scalloped but have a more crinkled texture and a distinct minty smell when crushed.
* Common Violet: The first true leaves of violets are heart-shaped, not perfectly round or shield-shaped.
If you’re unsure, let the plant grow for another few days. Nasturtium’s unique leaf shape becomes unmistakable very quickly.
Optimal Conditions for Nasturtium Seedling Growth
To get your seedlings off to a strong start, they need the right environment. Nasturtiums thrive on a bit of neglect, but getting the basics right helps.
Light Requirements
Nasturtium seedlings love plenty of light. Once they emerge, provide at least 6 hours of sunlight daily. In too little light, they become leggy, stretching weakly for the sun. A sunny windowsill or a bright spot in the garden is ideal.
Soil and Watering Needs
This is where many gardeners make a mistake. Nasturtiums prefer poor to average, well-draining soil.
* Do not use rich compost or fertilize. Too much nitrogen leads to massive leafy growth with few flowers.
* Let the soil dry out slightly between waterings. Overwatering is a major cause of failure. Soggy soil can cause the succulent stems to rot.
* Water gently at the base to avoid disturbing the delicate seedlings.
Temperature
Nasturtiums are frost-tender. Only sow seeds or place seedlings outdoors after all danger of frost has passed. They germinate best in soil temperatures of 55-65°F (12-18°C). Cool, wet soil can cause seeds to rot before they even sprout.
Caring for Your Young Nasturtium Seedlings
Once you’ve positively identified your sprouts, a little care ensures they mature into robust, flowering plants.
1. Thinning: If you sowed multiple seeds in one spot, thin the seedlings when they have 1-2 sets of true leaves. Choose the strongest one and snip the others at soil level with scissors. This prevents overcrowding.
2. Transplanting (If Started Indoors): If you started seeds in pots, transplant them outdoors once they’re sturdy and the weather is warm. Handle them by their leaves, not the fragile stem, to avoid damage.
3. Pest Watch: Keep an eye out for aphids, which are attracted to nasturtiums. A strong spray of water from the hose is often enough to dislodge them from seedlings.
4. Support for Climbers: If you’re growing a trailing or climbing variety, provide a trellis or support early so the tendrils can attach easily as they grow.
Frequently Asked Questions (FAQ)
Q: How long do nasturtium seeds take to sprout?
A: Under ideal warm conditions (55-65°F soil), nasturtium seeds typically germinate in 7 to 12 days. Cooler soil can slow this down to 2 weeks or more.
Q: Why haven’t my nasturtium seeds come up?
A: Several factors could be at play. The seeds might have been planted too deep (they only need a 1/2 inch covering), the soil could be too cold and wet, or the seeds may have been old and lost viability. Sometimes birds or insects dig them up, too.
Q: Can you eat nasturtium seedlings?
A: Yes, absolutely! Both the cotyledons and young true leaves are edible. They have a pleasant, peppery flavor similar to arugula. They make a great addition to salads and garnishes.
Q: Do nasturtium seedlings need fertilizer?
A: No, they do not. In fact, fertilizing nasturtium seedlings, especially with high-nitrogen plant food, will encourage excessive leafy growth at the expense of the bright flowers you’re likely growing them for. They perform best in lean soil.
Q: My seedlings are tall and spindly. What’s wrong?
A: This is called “legginess” and is almost always caused by insufficient light. The seedling is stretching to find more sun. Move them to a much brighter location as soon as possible. You can also gently bury a bit of the elongated stem when transplanting outdoors for support.
Q: What’s the difference between bush and trailing seedling types?
A: At the seedling stage, the difference is very subtle. Bush types might have a slightly more compact center from which leaves emerge, while trailing varieties may show a longer stem between leaf sets (internodes) early on. The growth habit becomes much more apparent as they mature.
Troubleshooting Common Seedling Problems
Even with the best care, issues can arise. Here’s how to address them.
* Yellowing Leaves: Usually a sign of overwatering. Allow the soil to dry out more thoroughly before watering again. Ensure pots have good drainage holes.
Wilting Seedlings: Could be underwatering or overwatering. Check the soil moisture an inch down. If it’s bone dry, water thoroughly. If it’s soggy, hold off and improve air circulation.
* Holes in Leaves: Likely caused by slugs or snails, which find young nasturtiums tasty. Check for slime trails and use an organic slug bait or trap at night.
* Seedlings Disappear Overnight: Birds, especially sparrows, sometimes pluck tender seedlings. Use a lightweight row cover or netting for the first few weeks after emergence for protection.
Recognizing what do nasturtium seedlings look like is the first step to a succesful patch of these cheerful, edible flowers. From their distinctive round cotyledons to their iconic shield-shaped true leaves, they have a unique apperance that’s easy to learn. With proper identification, you can give them the right care—plenty of sun, minimal water, and no fertilizer—to ensure they thrive. Soon enough, those identifiable seedlings will mature into a vibrant cascade of greenery and bright blooms for your garden and your plate.