Nasturtium Fertilizer Schedule: Companion Planting in Fabric Pots

Why Nasturtium Does So Well with Companion Planting

Okay, so let's chat about nasturtiums. Everyone thinks they're just a pretty face, right? Edible flowers, peppery leaves, look great trailing out of a hanging basket. And yeah, they totally are all of that. But beyond the aesthetics and the deliciousness, nasturtiums are secretly one of the best team players in your urban garden, especially when you're working with limited space like I always am in my tiny Brooklyn balcony setup.

I mean, think about it: if you're growing in a fabric grow bag, every inch counts. You want to maximize your output, deter pests naturally, and generally just make your plants happy. That's where companion planting with nasturtiums really shines. Their peppery scent can act like a big "stay away!" sign for some common garden pests. Aphids, for instance, are often drawn to nasturtiums as a trap crop, leaving your more prized veggies alone. It's like they're taking one for the team, and honestly, they don't even mind because they're such vigorous growers.

I've pretty much always got nasturtiums tucked in somewhere. Back when I was trying to grow tomatoes in a container in my Chicago apartment, I'd always have nasturtiums nearby. They're not just pest magnets, though. They act as "living mulch" by shading the soil, keeping it cooler and retaining moisture – super helpful for thirsty plants in hot summers. Plus, their roots can actually help break up compacted soil, which is a bonus in any container, but particularly in something like a fabric grow bag where drainage is already top-notch.

My go-to pairings? Well, I've had awesome luck using nasturtiums alongside things like radishes and carrots. The nasturtium leaves shade the soil, keeping the root veggies cool, which helps prevent bolting. And the radishes and carrots don't really compete for nutrients in the same way. It's a beautiful, symbiotic relationship. I wrote a whole piece on companion planting carrots and radishes, and guess which flower made a cameo? You got it.

What You'll Actually Need

Alright, let's get down to the nitty-gritty. What do you need to make this nasturtium-and-companion-planting dream a reality in your urban space?

Container: Fabric Grow Bag

First up, and this is non-negotiable for me these days: a fabric grow bag. Seriously, if you're not using them, you're missing out. I primarily use 5-gallon or 7-gallon bags for nasturtiums and their companions. They air-prune the roots, which means no circling, healthier plants, and better drainage. Plus, they're lightweight, easy to move, and fold flat for storage. I typically grab mine from a brand like Vego Garden or Root Pouch – they hold up really well. The fabric grow bag is key for nasturtiums because they really don't like soggy feet.

System: Companion Planting (with a little help from fertilizer)

Beyond the bag, you're going to need:

1. Good Quality Potting Mix: Don't skimp here. I'm a huge fan of FoxFarm Ocean Forest or Happy Frog for container growing. They're a bit pricey, but they're rich in organic matter and beneficial microbes, which gives your plants a fantastic head start. For nasturtiums, a well-draining, moderately fertile mix is perfect.
2. Nasturtium Seeds: Any variety works, but I love "Empress of India" for its deep red flowers and compact habit, or "Alaska Variegated" for the cool marbled leaves.
3. Companion Plant Seeds/Starts: For an 8-10 week cycle, think quick-growers. Radishes, lettuce, spinach, or even some bush beans are excellent choices. Their growth habits complement the nasturtium beautifully. For this guide, let's assume we're doing a classic nasturtium-and-radish combo.
4. Fertilizer: This is where the "nasturtium fabric grow bag fertilizer" magic happens. Nasturtiums aren't heavy feeders, especially in good soil, but a little boost at the right time makes a big difference. I use an organic all-purpose liquid fertilizer, something with an NPK ratio around 2-2-2 or 3-2-2. Brands like Alaska Fish Emulsion or Neptune's Harvest are fantastic for this.
5. Watering Can: Obvious, but important. Consistent, gentle watering is key.
6. Snips or Scissors: For harvesting and deadheading.

The Growing Process, Step by Step

Okay, let's walk through this 8-10 week journey. This is generally how I do it, from April to September here in USDA Zone 7a. Every February, I start my nasturtium seeds indoors under grow lights for a head start, but direct sowing works too once frost danger is past.

Week 1: Sowing and Settling In

• Fill Your Fabric Grow Bag: Fill your 5 or 7-gallon fabric grow bag with your chosen potting mix, leaving about an inch or two from the top.
• Sow Nasturtium Seeds: Nasturtium seeds are big, so they're easy to handle. Plant 3-4 seeds, spaced evenly, about 1 inch deep in the center of the bag. You can make a small depression, drop them in, and cover gently.
• Sow Companion Seeds: Around the edges of where you planted the nasturtium seeds, sow your companion plant seeds. If it's radishes, sprinkle them lightly, cover with about a quarter-inch of soil, and gently pat down.
• Water In: Give everything a good, gentle watering. Don't drown them, but make sure the soil is evenly moist.
• Placement: Find a spot that gets at least 6 hours of direct sunlight. Nasturtiums *love* sun. Last March, my first Nasturtium batch in a fabric grow bag got leggy because I skimped on light – lesson learned the hard way!

Weeks 2-3: Germination and First True Leaves

• Thinning: Once your nasturtium seedlings have their first set of true leaves (the ones that don't look like the initial seed leaves), thin them to the strongest 2 plants. Do the same for your companion plants if they came up too densely.
• Watering: Keep the soil consistently moist, but not waterlogged. Fabric grow bags drain well, so you'll probably be watering daily in warm weather. Feel the soil; if it's dry an inch down, it's time.
• First Nasturtium Fabric Grow Bag Fertilizer Feed: Around the end of Week 3, give your seedlings their first light feeding. Mix your liquid organic fertilizer (e.g., Alaska Fish Emulsion) at half strength. Nasturtiums really don't need much, especially early on.

Weeks 4-6: Rapid Growth and Budding

• Increased Watering: As plants get bigger, they drink more! Check your bag daily.
• Second Nasturtium Fabric Grow Bag Fertilizer Feed: Mid-period, around Week 5, give another half-strength dose of your liquid organic fertilizer. At this point, your companion plants (like radishes) are probably starting to bulb up, and the nasturtiums will be putting on serious leaf growth.
• Monitoring: Keep an eye out for pests. Nasturtiums are great at attracting aphids, but sometimes they attract *too many*. If you see a heavy infestation, you can spray them off with a strong jet of water or gently wipe them away.

Weeks 7-8: Flowering, Fruiting, and Companion Harvest

• Nasturtium Blooms: You should be seeing loads of those gorgeous, peppery flowers now! Harvest them regularly to encourage more blooms.
• Companion Harvest: Your radishes or lettuce should be ready for harvest. This is awesome because it frees up space and nutrients for the nasturtiums to really go wild.
• Third Nasturtium Fabric Grow Bag Fertilizer Feed: A final half-strength feed during this period helps sustain the flowering and leaf production. This ensures your nasturtium fabric grow bag fertilizer strategy keeps them happy and productive.

Weeks 9-10: Continued Harvest and Enjoyment

• Consistent Harvesting: The more you pick nasturtium flowers and leaves, the more the plant will produce. Don't be shy!
• Water & Monitor: Keep up with regular watering. In hot weather, you might even need to water twice a day.
• Enjoy! Your nasturtiums should be a vibrant cascade of color and flavor. Use the leaves in salads, the flowers as garnish, or even pickle the seed pods for "poor man's capers"!

Mistakes I've Made (So You Don't Have To)

Oh, believe me, I've messed up plenty with nasturtiums. One time, early in my micro-gardening journey when I lived in Portland, I thought "more fertilizer is always better!" Rookie mistake. Nasturtiums, especially if the soil is already good, can get really leafy and produce very few flowers if you hit them with too much nitrogen. The plant just thinks, "Awesome! I should focus all my energy on these lush greens!" It's like a teenager choosing snacks over studying. So, that first nasturtium fabric grow bag fertilizer application? Go light. Super light.

Another classic rookie move: Underestimating their sprawling nature. Even the "bush" varieties can get pretty big in a decently sized fabric grow bag. I once tried to tuck a nasturtium into a 3-gallon bag with a pepper plant – not a good look. The nasturtium practically smothered the pepper. Now, I give them more room, or I go for the vining types that I can train upwards or let spill dramatically over the edge.

Also, don't ignore the aphids. Yeah, they're a trap crop, but if you let them get utterly out of hand, they'll stress the nasturtium too much, and then it won't be able to protect its companions effectively. A quick spray of water or a dab of insecticidal soap (if you're a bit more advanced) can keep them in check without harming the plant or the edible parts.

Little Things That Make a Big Difference

• Warm Water for Soaking: Some folks soak nasturtium seeds overnight in warm water before planting. It can speed up germination. I don't always do it, but when I remember, it works!
• Harvesting Regularly: I cannot stress this enough. For flowers, for leaves, for companion crops. The more you harvest, the more the plant feels compelled to produce more. It’s the plant's way of ensuring its survival.
• Pinching Back: If your nasturtium starts looking a bit leggy or too enthusiastic in one direction, don't be afraid to pinch back some of the newer growth. This encourages bushier growth and more flowers.
• Check those roots! With a fabric pot, you can sometimes see roots trying to peek through the fabric. It’s a good sign of healthy growth, but also a reminder that they’re actively air-pruning.

When to Harvest and What to Expect

The beauty of nasturtiums is that pretty much the whole plant is edible (except the roots, usually). You can start harvesting leaves as soon as they're a decent size, usually around Week 4-5. They'll have that classic peppery, slightly mustardy bite. Great in salads, sandwiches, or blended into pesto.

The flowers usually start appearing around Week 7 or 8. Pick them regularly! They're fantastic for garnishing, adding a pop of color and a mild peppery flavor to dishes. Pick them in the morning after the dew has dried for the best flavor and shelf life.

And those little green seed pods? Don't toss 'em! If picked when young and still soft, they're often called "poor man's capers." You can pickle them in a simple brine, and they make a wonderful tangy addition to various dishes. I've got a whole post on growing nasturtium in a tin can where I dive deeper into these edible delights.

For your companion plants, follow their typical harvest schedules. Radishes, for example, are usually ready in about 3-4 weeks from sowing. Harvest them promptly so they don't get woody or bitter.

With this nasturtium fabric grow bag fertilizer approach, you're not just growing a pretty plant; you're creating a mini-ecosystem that's productive, pest-resistant, and honestly, just a joy to watch flourish. Give it a try, you won't regret it!