Nasturtiums are the cheerful, low-maintenance flower that almost grows itself. With big seeds you can poke straight into the ground, jewel-toned blooms in shades of orange, red, and gold, and peppery leaves and flowers you can toss into a salad, they reward beginners and busy gardeners alike. Best of all, they actually prefer to be neglected, which makes them perfect for anyone who tends to forget the watering can.
Nasturtium quick facts
- Grow in poor soil — rich soil = leaves, few flowers
- Direct-sow the big seeds after the last frost
- Full sun, little water, no fertilizer
- Flowers & leaves are edible (peppery)
- Great trap crop for aphids; self-seeds
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Choosing Your Nasturtium: Bush vs. Trailing Types
Before you sow a single seed, it helps to know which kind of nasturtium you’re growing, because the two main forms behave very differently in the garden. Most seed packets fall into one of two camps, and choosing the right one for your space is the difference between a tidy border and a sprawling jungle.
Bush (dwarf) nasturtiums
Bush types stay compact, usually 10 to 14 inches tall, forming neat mounds that don’t ramble. They’re the right pick for edging a path, filling a small bed, or planting in pots where you want a clean, controlled shape. Look for varieties labeled “Tom Thumb,” “Alaska,” or “Whirlybird” on the packet.
Trailing and climbing nasturtiums
Trailing types send out long vines that can run 6 to 10 feet, scrambling along the ground or climbing a trellis if you give them something to grab. These are the show-stoppers for hanging baskets, where they spill over the edge in a curtain of blooms, and they double as a fast, flowery ground cover. “Tall Single Mix” and old-fashioned heirloom climbers belong here. You’ll find a wide range of both forms in packets of nasturtium seeds.
The “Poor Soil” Rule (Why Rich Soil Backfires)
This is the single most important thing to understand about nasturtiums, and it’s the opposite of what most gardening advice tells you. Nasturtiums bloom best in poor, lean soil. Plant them in rich, compost-heavy, or heavily fertilized ground and you’ll get a magnificent leafy plant with hardly a flower in sight.
Why this happens
- High nitrogen (from compost or fertilizer) pushes the plant to grow lush foliage instead of setting blooms.
- Lean, slightly sandy or rocky soil signals the plant to flower and set seed instead of bulking up on leaves.
- Good drainage matters far more than fertility — nasturtiums hate soggy, heavy soil.
The takeaway is simple: don’t pamper them. Skip the compost, skip the fertilizer, and plant them in the spot where nothing else seems to thrive. That “bad” corner of your yard is often exactly where nasturtiums put on their best show. For the broader principles of matching plants to conditions, see our plant & flower care guide.
How to Direct-Sow Nasturtium Seeds
Nasturtiums have large, wrinkly seeds about the size of a chickpea, which makes them one of the easiest flowers for kids and beginners to plant. They also dislike being transplanted, so direct-sowing right where they’ll grow is almost always the best approach.
Step by step
- Wait until all danger of frost has passed and the soil has warmed — nasturtiums are frost-tender and won’t germinate in cold ground.
- Choose a sunny spot with lean, well-draining soil. No need to amend it.
- Poke each seed about 1 inch deep, spacing them 8 to 12 inches apart.
- Water gently and keep the soil lightly moist until sprouts appear, usually in 7 to 14 days.
- Once they’re up and growing, ease off the water and let nature take over.
To speed up germination, you can soak the seeds in water overnight or lightly nick the hard outer coat with a nail file. If you’re in a short-season climate and want a head start, sow into biodegradable seed starting trays a couple of weeks before your last frost, then plant the whole pot out to avoid disturbing the roots.
Light, Water, and Feeding (Less Is More)
If you remember one thing about caring for nasturtiums, make it this: do almost nothing. They are a true “neglect me” plant, and over-attention is the most common way gardeners go wrong.
Sun
Give nasturtiums full sun — at least 6 hours a day — for the most flowers. They’ll tolerate part shade, but expect more leaves and fewer blooms in shadier spots.
Water
Water established plants sparingly, only when the soil is dry an inch down. They’re surprisingly drought-tolerant, and constant moisture invites rot. Container plants will need more frequent watering than those in the ground, since pots dry out faster.
Feeding
Don’t feed them at all. Fertilizer is the enemy of nasturtium flowers. If you notice plenty of leaves but no blooms, the cause is almost always too much nitrogen — back off entirely and the plant will usually start flowering within a couple of weeks.
Growing Nasturtiums in Containers, Baskets, and as Ground Cover
Nasturtiums are wonderfully flexible. The same plant can edge a vegetable bed, tumble from a balcony rail, or blanket a bare slope, depending on the variety you choose.
Containers and hanging baskets
Trailing types are made for hanging baskets, where their vines cascade over the sides in a waterfall of color. Use a basic potting mix with good drainage — and resist the urge to grab the “premium” mix loaded with slow-release fertilizer, which will give you all foliage. Make sure every pot has drainage holes, and remember that container nasturtiums dry out faster, so they’re the one exception to the low-water rule.
Ground cover
Let trailing varieties run along the soil and they’ll knit together into a dense, weed-suppressing mat covered in blooms. This makes them a fast, inexpensive way to dress up a sunny bank or fill the gaps between young shrubs while they establish.
Eating Nasturtiums and Letting Them Self-Seed
Nasturtiums aren’t just pretty — the entire plant above ground is edible, with a bright, peppery bite similar to watercress or arugula. They’re one of the easiest edible flowers to add to a kitchen garden alongside your herb garden.
What’s edible
- Flowers: mild and peppery, beautiful scattered over salads or used as a garnish.
- Leaves: a stronger peppery kick — great chopped into salads or blended into a nasturtium “pesto.”
- Seed pods: the green, immature pods can be pickled like capers (sometimes called “poor man’s capers”).
Only eat flowers and leaves you’ve grown yourself or know to be unsprayed. And if you let some flowers go to seed at the end of the season, nasturtiums will happily self-seed, dropping seeds that sprout on their own the following spring. In mild climates they can pop up year after year with no effort from you — though they’re easy to pull if they wander where you don’t want them.
Nasturtiums as a Companion and Trap Crop
One of the best reasons to grow nasturtiums is what they do for the rest of your garden. They’re a classic companion plant and one of the most effective trap crops you can grow.
A magnet for aphids
Aphids are strongly drawn to nasturtiums — even more than to your vegetables. By planting nasturtiums nearby, you lure the aphids onto the nasturtiums and away from your prized crops, a strategy known as trap cropping. The nasturtiums take the hit, and you can simply remove the most infested vines or hose them off. For a full rundown of dealing with infestations, see how to get rid of aphids.
Good neighbors
Nasturtiums are said to benefit cucumbers, squash, beans, tomatoes, and brassicas, and their flowers attract pollinators and beneficial insects to the whole garden. They pair beautifully with a vegetable patch. To plan the rest of your beds, our companion planting guide covers which plants thrive together.
Deadheading and Season-Long Care
To keep nasturtiums blooming from early summer until frost, the most useful habit is regular deadheading — removing the spent flowers before they form seeds. When a plant senses it has set seed, it slows down flower production, so snipping off faded blooms tricks it into making more.
- Pinch or snip spent flowers and any developing seed pods every few days for the heaviest, longest bloom.
- Trim back any leggy, overgrown vines to encourage fresh, bushy growth.
- Toward the end of the season, leave a few flowers to set seed if you want them to return next year.
That’s the whole secret: poor soil, full sun, little water, and an occasional snip. Treat them rough and nasturtiums will thank you with months of edible color.
Frequently asked questions
Why does my nasturtium have lots of leaves but no flowers?
The soil is too rich or you’re fertilizing. High nitrogen drives leafy growth at the expense of blooms. Stop feeding, move them to leaner, full-sun soil, and they’ll usually start flowering within a week or two.
When should I plant nasturtium seeds?
Direct-sow the seeds outdoors after all danger of frost has passed and the soil has warmed. They’re frost-tender and germinate poorly in cold ground, so there’s no benefit to planting too early.
Are nasturtiums really edible?
Yes. The flowers, leaves, and immature green seed pods are all edible, with a peppery flavor like watercress. Just be sure they’re unsprayed before eating.
Do nasturtiums come back every year?
They’re tender annuals, so they’re killed by frost. However, if you let some flowers go to seed, they readily self-seed and often reappear on their own the following spring — and in frost-free climates they can persist year-round.
Do nasturtiums need full sun?
For the best flowering, give them at least 6 hours of direct sun a day. They tolerate part shade but will produce more foliage and fewer blooms in shadier spots.