UBCNews - Business - Indoor Gardening 101: The Best Type Of Fertilizer For Houseplants & Vegetables

Episode Date: December 5, 2025

Welcome back, everyone! Today we're tackling a question that trips up so many home gardeners - do our houseplants actually need fertilizer, and if so, what kind should we be using? I'm joined by a guest who knows indoor gardening inside and out. Let's jump right in. So, first things first - do houseplants really need fertilizer? GS Plant Foods City: Lake Mary Address: 4300 West Lake Mary Boulevard Website: https://gsplantfoods.com/

Welcome back, everyone. Today, we're tackling a question that trips up so many home gardeners. Do our houseplants actually need fertilizer? And if so, what kind should we be using? I'm joined by a guest who knows indoor gardening inside and out. Let's jump right in. So first things first, do houseplants really need fertilizer? That's a great question to start with.

The short answer is yes, they do. Here's the thing. Outdoor plants pull nutrients from the soil naturally, but our house plants, they're basically relying on us to provide everything they need. Through photosynthesis, plants manufacture sugars and carbohydrates, but they need at least 16 different elements to carry on that process. Right, so we're essentially their nutrient delivery service.

What happens if we skip fertilizing altogether? You'll start seeing some pretty telltale sense. signs. Slow growth is usually the first clue. Then you might notice weak stems, pale leaves, and if it's a flowering plant, reduced blooms. Plants get carbon, oxygen, and hydrogen from air and water. But all those other nutrients? That's where fertilizer comes in. Mm-hmm, makes sense. So when we're shopping for fertilizer, what should we actually be looking for? I know there are so many options out there, and honestly, it can feel overwhelming. Oh, definitely.

Let me break it down. First, you'll see three numbers on every fertilizer package, something like 20, 2020. Those are the NPK numbers, and they're super important. N stands for nitrogen, P for phosphorus, and K for potassium. Each one plays a different role. nitrogen encourages that lush green leafy growth. Phosphorus supports flowering and root development. And potassium.

That's for stem strength and helping plants handle stress. So those three numbers tell us the percentage of each nutrient in the mix? Exactly. Higher ratios mean more concentrated fertilizer. A balanced fertilizer, where those three numbers are roughly equal, works well for most house plants. Think of it as an all-purpose option. You know, I learned this the hard way when I first started.

I grabbed some random fertilizer and my fiddly-fig looked absolutely miserable for weeks. Turned out, I'd picked something way too high in one nutrient. Once I switched to a balanced formula, boom, total turnaround. Ha, yeah, we've all been there with trial and error. and I've heard people talk about micronutrients too. Are those important? They are, yeah.

Micronutrients include things like iron, zinc, boron, copper. Plants need them in much smaller amounts than the big three, but they're still essential. If you're using a soilless potting mix, which a lot of us are, those micronutrients typically aren't present. So you'll want to look for a fertilizer that includes them, or go with an organic option. That actually brings up a good point about organic versus chemical fertilizers.

What's the real difference there? Honestly, both do the same job just in different ways. It comes down to personal preference. Organic fertilizers, derived from natural sources, tend to be gentler on sensitive plants and usually contain those micronutrients we just talked about because of their nature. Chemical fertilizers are formulated with almost perfect ratios of both macro and micronutrients,

which can be easier for beginners. I see, go on. So let's talk about the different forms fertilizer comes in. Liquid, granular, slow release. How do we choose? Great question. Liquid fertilizers are diluted in water and give you the most control. You can adjust how much and how often you feed based on the season.

Water-soluble powders or liquid concentrates are perfect if you're fertilizing weekly, bi-weekly, or monthly. Granular types are dry pellets mixed into the soil surface. They release nutrients when you water. They're inexpensive, but harder to control precisely. Then you've got slow-release options, which break down over three to six months. That point about control and different application methods sets up our next piece. how these products actually work in the soil. But first, a quick word from our sponsor.

Looking for fertilizer options that work for both your houseplants and vegetable gardens? GS plant foods specializes in plant nutrition products formulated from organic, all-natural ingredients. Their product line includes liquid concentrates and water-soluble powders designed to boost plant growth naturally. With options like their 2020, all-purpose fertilizer with kelp, and micronutrients, organic fish and kelp fertilizer, and liquid kelp fertilizer. These fertilizers are safe for people and pets while improving plant tolerance to heat, wind, and drought. Learn more at gsplantfoods.com. Picking up on those application methods, when should we actually be fertilizing our plants?

Is there a best season or is it year-round? Timing is key. House plants typically respond to fertilizer during their active growing season, which is usually March through October for most indoor plants. During winter months, reduced light and cooler temperatures often make plants go dormant, so it's generally recommended to stop or significantly reduce fertilizing then. Of course, this can vary depending on your specific plant and environment. Right, so we're matching the feeding schedule to their natural rhythm. And how often during the growing season? Most water-soluble fertilizers recommend monthly

applications, but here's a pro tip. You can actually feed more frequently with diluted solutions. If the label says one teaspoon per quart monthly, you could do half a teaspoon every two weeks, or even a quarter teaspoon weekly. That gives plants a steady supply of nutrients, really a continuous flow of what they need without overwhelming them. This works really well for flowering plants. So more frequent but weaker doses? Right. And this is critical. Always follow label directions. More isn't better with fertilizer. In fact, over-fertilization can cause serious problems. Always water your plant thoroughly first, then apply fertilizer to the already moist soil.

This helps prevent root burn. What does over-fertilization look like? How would someone know they've gone too far? You'll see several warning signs. Browning on root tips and leaf edges is common, along with wilting even when the soil is moist. There's often a white crusty buildup on the pot rim from excess fertilizer salts. You might also notice yellowing of lower leaves or lack of new blooms on flowering plants.

High concentrations actually prevent plants from taking up water, which causes that wilting. If you catch it early, you can often fix it by leaching the pot, running lots of water through until it drains freely. Or you might need to repot with fresh potting mix. That's really helpful to know. Um, let me ask you this. If someone has a mix of different plants, do they need different fertilizers for each one? Not necessarily. While it's true that foliage plants tend to appreciate higher nitrogen for leafy growth, and flowering plants often respond better to higher phosphorus, a balanced fertilizer usually,

works well across the board, especially for beginners. An all-purpose formula where the three numbers are roughly equal keeps things simple and still provides what most houseplants need. So to everyone listening, if you're just starting out, a balanced fertilizer is probably your safest bet. Have you ever looked at your plant collection and thought, am I feeding this right? One last thing I want to cover. Any tips for people just adding fertilizer to their routine for the first time? Definitely start slow. When you begin fertilizing in spring, introduce it gradually so plants can adjust. Make the first few applications at half the recommended strength. Your plants don't need large amounts right away as they're just gearing up for the

growing season. It's always better to underfertilize than overdo it. I mean, you can always add more later, but you can't take it back once it's in the soil. That's solid advice. You know, it seems like such a fundamental part of plant care, yet so many people skip it or feel intimidated. I think people get intimidated by all the numbers and options. But once you understand the basics, NPK ratios, when to feed, how much to use, it really becomes second nature. plants give us so much and providing them with proper nutrition is one of the simplest ways

we can support their health. Absolutely. Together we're helping people create thriving indoor gardens. Well, that wraps up our conversation today. Thanks so much for sharing your expertise on fertilizing houseplants and vegetables. For everyone listening, remember,

healthy plants start with good nutrition, proper watering, adequate light, and a little attention. Happy gardening.