Let's Talk About Growth
What could be more satisfying than that burst of life when peak gardening season hits?
That moment when your leafy greens double in size overnight, or your strawberries go from buds to berries in one warm week. Good soil, sunny conditions, and consistent watering are garden staples, while the key to the next level of vitality lies in what you feed them.
Whether you’re brand new to vertical gardening or ready to level up your results, this guide will walk you through everything you need to know about fertilizing a GreenStalk, including how to keep track of your progress.
Granular vs. Liquid Fertilizer: What’s the Difference?
Every plant needs a few key nutrients to grow: nitrogen for leafy green growth, phosphorus for strong roots and flowers, and potassium for overall health and resilience. A well-built potting mix includes some of these, but as your plants grow, they’ll naturally use them up.
Granular fertilizer is your GreenStalk’s first feast. It’s typically mixed into the lower ⅔ of your soil before planting and releases nutrients slowly over time. By topping the mixed-in fertilizer soil with plain potting soil, you give starter plants and transplants the nutrients they need while leaving room for baby plants to grow into the full meal. This gives your plants a strong foundation from the jump. One great option is the Fox Farm Organic Jump Start Fertilizer 3-4-3 , which is ideal for seedlings and transplant support.
On the other hand, liquid fertilizer acts fast. You dilute it in water and apply it directly into the top water reservoir or to the individual pockets. Liquid feeding is perfect for giving plants a boost, encouraging flowering, or supporting heavy-producing crops. We recommend Fox Farm Grow Big Fertilizer 6-4-4 to promote lush vegetative growth.
While worm castings are technically a supplement fertilizer, they’re usually added when building your initial soil mix. They help improve microbial activity and root health, and are gentle on plants such that they can be added throughout the growing season. You can experiment with worm castings throughout a plant’s life cycle to learn which plants thrive on a boost of micronutrients and how often to apply.
How Often Should You Fertilize?
Fertilizing doesn’t need to follow a rigid schedule, but having a simple rhythm helps. Incorporate granular fertilizer once, ideally when filling your GreenStalk for a new season. That single step sets a nutrient-rich foundation.
Seeds and seedlings, typically before they have two true sets of leaves, are sensitive to fertilizer and need much less than their more mature counterparts. For smaller plants, consider using a ¼ strength dose of liquid fertilizer and increase the strength as your plants grow.
Some plants are heavy feeders (like tomatoes and cucumbers) and will appreciate regular doses. Others, like many herbs, prefer a lighter touch. Always water first if the soil is dry to avoid root burn, and hold off on feeding during extreme heat or right after transplanting.
When adding liquid fertilizer, follow the directions on the bottle, adding a full dose every two weeks or a half dose every week.
Over time, you’ll start to notice what each plant needs, and when. It’s not black and white or an exact science, but an opportunity to discover what works in your garden.
How to Tell When Your Plants Need a Boost
Your garden will tell you what it needs, you just have to know what you’re looking for.
If the lower leaves start turning yellow, it may be a sign of nitrogen deficiency.
If growth feels stunted or leaves have a purplish hue, phosphorus could be lacking.
Browning or curling edges on older leaves may suggest a need for potassium.
Don’t worry about diagnosing perfectly, because all of those indicators can also be from over- or underwatering, disease, temperature stress, or the end of the plant’s life cycle. These clues are simply signals to check in and respond. A single feeding with liquid fertilizer can often give a noticeable boost to a struggling plant.
Keep Track, Grow Smarter
One of the best ways to feel more confident in your fertilizing routine is to keep notes — and that’s where the GreenStalk Garden Journal shines.
This simple, gardener-friendly notebook lets you:
Record what fertilizer you used and when
Track plant responses like growth spurts or leaf changes
Create crop-specific cheat sheets to reuse each season
Stay curious and adjust with intention
You don’t have to log every detail—but even a quick note like “Fed lettuce – Grow Big – looks greener already ;)” can help you learn what works in your space.
Over time, these observations become a personalized growing guide—one that helps you plant smarter, harvest more, and enjoy the process all the more.
If you’ve never fertilized before, try adding granular fertilizer to your next new planting. Already in the middle of your season? Add a serving of liquid fertilizer to those plants that look to need it most and see how it goes. The beauty of gardening is that there’s no one right way to do it. Just remaining present with your plants and learning the rhythm of growth as seasons change.
Need Gardening Advice?
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