The Cheapest Ways to Fill Your Planters Like a Pro

Container gardening is fantastic planters like a pro. It lets you add splashes of color to patios, grow veggies on balconies, or bring nature indoors, even if you don’t have a sprawling yard. But anyone who’s eyed up those gorgeous, oversized planters knows the hidden cost: filling them! Bag after bag of premium potting mix can quickly drain your gardening budget, and large, soil-filled pots become incredibly heavy.

Fear not, green-thumbed friend! There’s a smarter, cheaper way. By using readily available filler materials for the bottom portion of your pots, you can significantly reduce the amount of expensive potting soil needed, make your planters lighter and easier to move, and often repurpose items destined for the landfill. Let’s dive into the most cost-effective strategies to get your planters filled and flourishing without breaking the bank.

Table of Contents

Unlock Savings with Smart Planter Fillers

What do you fill fake planters with

The core idea is simple: planters like a pro generally only need soil in the top portion of the pot where their roots grow. The space below can often be filled with lighter, cheaper materials. Think volume, not just soil! Here are some popular and budget-friendly options:

Recycled Treasures: Before you toss those empty plastic containers, consider their potential! Clean plastic water bottles, soda bottles (keep the caps on to prevent water filling them), milk jugs, and yogurt containers make excellent lightweight fillers. Crushed aluminum cans also work well. Simply place them in the bottom of your planter.
- Pros: Free, extremely lightweight, keeps plastic out of landfills (at least for a while).
- Cons: Non-biodegradable. Some gardeners express concern about potential chemical leaching from plastics over time, especially for edible planters like a pro , though many use them without issue. Aluminum is generally considered safe.
Nature’s Bounty: Your yard might hold the key to free planter filler. Pine cones, fallen leaves (especially oak leaves which break down slowly), small twigs, and wood chips can all be used to take up space.
- Pros: Free, organic, eventually decompose to add some nutrients (though minimal compared to compost).
- Cons: Organic materials will break down over time, causing the soil level in your planter to sink. You’ll need to top it up periodically. They can also potentially harbor pests or diseases if not sourced carefully, and may compact, reducing drainage if used too densely.
Lightweight Wonders: Think packaging! Non-biodegradable packing peanuts (the styrofoam kind, not the cornstarch ones that dissolve in water) are incredibly light. To prevent them from mixing with the soil or spilling out if you repot, it’s wise to contain them within a mesh bag, an old pillowcase, or even an empty potting soil bag before placing them in the planters like a pro.
- Pros: Extremely lightweight, readily available, repurposes waste.
- Cons: Styrofoam is non-biodegradable and an environmental concern if it escapes into the environment.
Weighty Matters (Use Sparingly & Strategically): Broken terracotta pots, chipped ceramic tiles, gravel, or medium-sized rocks can be used at the very bottom. These add stability, which can be useful for very large, top-heavy planters in windy locations.
- Pros: Adds weight for stability, repurposes broken items, can potentially aid drainage if layered correctly .
- Cons: Adds significant weight, making planters hard to move. If not layered properly or if drainage holes are blocked, they can actually impede water flow.

The Secret Sauce – Affordable Soil Solutions

Reducing the volume needed is step one, but the soil you do use still costs money. Here’s how to be savvy about your gowing medium:

Bulk Buying Power: If you have multiple containers or raised beds to fill, buying potting mix, compost, or soil components like planters like a pro moss, coco coir, perlite, and vermiculite in bulk is almost always cheaper per unit volume than buying small bags. Check local nurseries, landscape suppliers, or even municipal composting facilities. You might need a truck, or see if delivery is an option for a reasonable fee.
DIY Potting Mix Magic: Crafting your own potting mix is surprisingly easy and significantly cheaper than pre-mixed bags.
- 1 part Coconut Coir or Peat Moss (for moisture retention)
- 1 part Compost or well-rotted manure (for nutrients and structure)
- 1 part Perlite or Vermiculite (for aeration and drainage – perlite drains faster, vermiculite holds more moisture) Mix these components thoroughly in a large tub or on a tarp. Wear a mask, especially when handling dry peat moss or perlite, to avoid inhaling dust.
Giving Old Soil New Life: Don’t throw out potting soil from last season’s containers! Unless the previous plants had serious diseases (like fungal wilts or root rot),

1. Sift & Clean: Dump the old soil onto a tarp and remove old roots, rocks, weeds, and visible pests.
2. Sterilize (If Necessary): If you suspect disease or pests (like fungus gnats), you can sterilize the soil. Spread it thinly on a dark plastic sheet in full sun for 4-6 weeks (solarization), or bake it in an oven-safe tray at 180-200°F (82-93°C) for about 30 minutes (let it cool completely before using).
3. Replenish & Revive: Old soil is depleted of nutrients and its structure might be compacted. Mix it roughly 50/50 with fresh compost. Add a handful of worm castings or a balanced, slow-release organic fertilizer.

Layer Like a Pro – The Perfect Planter Setup

Okay, you’ve gathered your fillers and sorted your soil. Here’s how to put it all together for happy plants and a happy wallet:

Drainage is King: Ensure your planter has adequate drainage holes at the bottom. If not, drill some! Without drainage, roots will sit in water and rot, no matter what fillers you use.
Add Filler: Place your chosen filler material (recyclables, natural items, styrofoam etc.) in the bottom of the planter. How much? Aim to fill the bottom 1/3 to 1/2 of the pot’s depth, depending on the planter size and the root depth needs of your plants. Shallow-rooted annuals need less soil depth than perennials or shrubs.
The Separator: This is key! Place a layer of landscape fabric, window screen, or even a couple of layers of newspaper over the filler material. This prevents your valuable potting soil from washing down into the filler layer while still allowing excess water to drain through.
Soil Time: Add your rejuvenated old soil, DIY mix, or new potting soil on top of the fabric separator. Fill to a level that allows enough room for your plant’s root ball.
Plant Away: Gently place your plant in the pot, ensuring the top of its root ball is about an inch below the rim of the planter. Fill in around the roots with more soil, gently firming it down.
Water Well: Water your newly potted plant thoroughly until water runs out the drainage holes. This helps settle the soil around the roots.
Mulch (Optional but Recommended): Adding a layer of organic mulch like shredded bark, wood chips, or even more leaves on top of the soil can help retain moisture, reducing watering needs, and suppress weeds.

Smart Considerations Before You Fill

While using fillers is generally a fantastic cost-saving strategy, keep a few things in mind:

Soil Sinking: Organic fillers (leaves, twigs, wood chips) will decompose and compress over time. Expect the soil level to drop, requiring you to top it up with more soil or compost each season. Non-biodegradable fillers like plastic or styrofoam won’t have this issue.
The Drainage Layer Debate: For years, adding a layer of gravel at the bottom was standard advice for drainage. However, some soil scientists argue this can create a “perched water table,” where water sits in the soil above the gravel layer because the change in texture impedes capillary action. Recent experiments suggest drainage layers can help, especially with coarser soil mixes, but the most critical factor remains having sufficient drainage holes. If using gravel, ensure it doesn’t block these holes and always use a separator fabric.
Edible Plants: If growing vegetables or herbs, be more cautious about your fillers. Avoid treated wood. While many use plastics without problems, if you’re concerned about potential leaching, stick to natural, inert materials like pine cones, broken terracotta, or invest more heavily in making your own quality soil mix.
Root Depth: This method works best for plants with shallow to moderate root systems (most annuals, many perennials, smaller shrubs). Very deep-rooted plants like large vegetables (think mature tomatoes or root veggies) or trees might require a greater volume of actual soil. Research your specific plant’s needs.

People Also Ask (FAQs)

Q1: Can I use styrofoam to fill the bottom of a planter?

Yes, you absolutely can use styrofoam (like packing blocks or non-dissolving packing peanuts) as a lightweight filler. It takes up space effectively and doesn’t add weight. It’s best to break up large blocks and contain peanuts in a bag for easier management and to prevent them from mixing with the soil. Remember, it’s not biodegradable.

Q2: How much filler should I use in a large planter?

A general guideline is to fill the bottom 1/3 to 1/2 of the planter’s depth with filler material. However, the exact amount depends on the size of the planter and, more importantly, the mature root depth requirements of the specific plants you intend to grow. Always ensure you leave enough depth (at least 6-12 inches, often more) of actual soil for healthy root development planters like a pro.

Q3: Is it okay to use rocks in the bottom of planters?

Yes, rocks or gravel can be used, primarily to add weight for stability in large, potentially top-heavy planters like a pro . They can also help keep drainage holes clear if placed carefully. However, they add significant weight, making pots difficult to move. The traditional idea that they universally improve drainage is debated; good drainage holes are more crucial. Always use a landscape fabric layer between rocks and soil.

Q4: Can I mix garden soil with potting soil for containers?

It’s generally not recommended. Soil straight from the garden tends to be dense and contains clay, which compacts easily in the confined space of a pot. This compaction reduces aeration and drainage, potentially leading to root rot. Potting mixes (commercial or DIY) are specifically designed to be lighter and provide better drainage and air circulation for containerized roots. If you must use garden soil, amend it very heavily (at least 50%) with compost and aeration materials like perlite or coco coir.

Q5: What can I use instead of perlite for drainage?

Several materials can substitute for perlite to improve aeration and drainage in potting mixes:

Vermiculite: Similar volcanic rock origin, but holds more moisture than perlite while still providing aeration.
Coarse Sand: Use horticultural sand or builder’s sand (not play sand, which is too fine). Adds drainage but also weight.
Small Gravel/Crushed Granite: Adds drainage but also significant weight.
Rice Hulls: A lightweight, sustainable byproduct, provides good aeration but breaks down over a season or two.
Pumice: Another lightweight volcanic rock, excellent for drainage.
Well-structured Compost & Coco Coir: Sometimes, a mix rich in chunky compost and fibrous coco coir provides enough structure and drainage without needing extra aggregates.

Conclusion: Grow More, Spend Less

Filling those beautiful planters doesn’t have to empty your wallet. By strategically using inexpensive or free filler materials for the bottom portion and getting smart about sourcing or creating your own soil mix, you can dramatically cut costs. These methods not only save money but also make planters like a pro significantly lighter and easier to handle, all while potentially reducing landfill waste. So go ahead, embrace container gardening on a grand scale – your budget, your back, and your beautiful blooms will thank you! Happy planting!