Wick System Kids' First Garden

At a Glance

How This System Works

A wick system is the simplest form of hydroponics and the perfect first project for kids. Each planter has two parts: an upper container filled with growing medium where the plant lives, and a lower container that acts as a nutrient reservoir. Cotton wicks connect the two, drawing nutrient solution up from the reservoir into the root zone through capillary action — the same process that makes a paper towel soak up a spill.

There are no pumps, no timers, and no electricity. The wicks work automatically, keeping the growing medium moist without overwatering. Kids can watch roots grow, observe how plants drink water, and learn basic science concepts like capillary action, photosynthesis, and plant nutrition.

Why recycled containers? This project uses materials most families already have at home — plastic bottles, yogurt cups, and food containers. Building a garden from "trash" teaches kids about recycling and resourcefulness while keeping costs as low as possible.

Materials List

Our philosophy: Use what you already have. Hydroponics does not require store-bought equipment. People around the world grow food this way using recycled containers, scraps of fabric, and seeds saved from last season's harvest. The links below are for convenience if you prefer to purchase, but we encourage you to improvise with what is available to you.

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Wick Cord

Cotton wick cord draws nutrient solution from the reservoir up to the roots. This is the easiest thing in the whole project to find for free. Strips of an old cotton t-shirt, cotton shoelaces, cotton rope from a hardware store, or even strips of felt all work beautifully. The whole point of a wick system is that it is simple enough for anyone to build from things around the house. If you want a ready-made spool, cotton wick cord (50 ft) will last through many projects.

Growing Supplies

Starter plugs: Cotton balls or small sponge pieces hold seeds until they sprout. Kids can even fold a damp paper towel around the seeds. If you want something ready to go, Rapid Rooter plugs (50-pack) are fun for kids to use and last a long time.

Nutrients: This is the one thing you do need to buy. Plants growing in perlite need dissolved minerals in the water. A single small bottle lasts months at the diluted strength used for herbs. A General Hydroponics Flora Series (3-part kit) is a solid choice.

Monitoring

A pH/EC meter helps mix nutrients at the right strength (optional for this beginner build, but helpful for learning). pH test strips from a pet store teach the same concept at a lower price. For a digital option, a digital pH and TDS meter kit turns nutrient mixing into a fun science activity.

Recycled & Household Materials (no affiliate link)

These items can be found around the house or purchased inexpensively:

• 3 to 5 plastic bottles (16 oz or 2-liter), cut in half to make the planter and reservoir
• Or 3 to 5 large yogurt containers or deli cups, one for the plant, one for the reservoir
• Perlite or vermiculite (small bag), lightweight growing medium safe for kids to handle
• Cotton string or cotton shoelace (if not using wick cord), must be 100% cotton, not synthetic
• Herb or lettuce seeds, choose fast-growing varieties kids will enjoy
• Non-toxic paint, stickers, or markers, for decorating the containers
• Rubber bands or tape, for securing wick cord
• Small rocks or pebbles, optional, for weighing down the wick in the reservoir

Tools

No power tools required. This build is kid-safe:

• Scissors (adult supervision for younger children)
• A nail or pushpin, for poking wick holes
• Measuring cup for nutrients
• Marker for labeling planters

Build Instructions

Step 1: Collect and Clean Recycled Containers

Gather 3–5 plastic bottles or food containers. For each planter you need two pieces:

Plastic bottle method (recommended):

• Cut a 2-liter or 16 oz plastic bottle in half horizontally
• The top half (with the cap) becomes the planter — flip it upside down so the neck points down
• The bottom half becomes the reservoir
• The inverted bottle top sits inside the bottom half, creating a self-contained unit

Yogurt cup method:

• Use one cup as the planter (poke drainage holes in the bottom)
• Use a second, slightly larger cup as the reservoir
• The planter cup sits inside or on top of the reservoir cup

Let kids choose which containers to use — creativity is part of the fun.

Step 2: Decorate the Containers

Before assembling, let kids personalize their planters:

• Paint the outside of the reservoir container with non-toxic paint (this also blocks light)
• Add stickers, draw faces, write plant names, or wrap with colorful tape
• Let paint dry completely before proceeding
• This step makes the garden feel like their own project

Step 3: Prepare the Wicks

• Cut cotton wick cord into 8–10 inch lengths (one per container)
• For the plastic bottle method: thread the wick through the bottle cap opening, leaving 3–4 inches hanging below into the reservoir and 4–5 inches coiled inside the planter
• For the yogurt cup method: thread the wick through one of the drainage holes in the planter bottom
• The wick must make contact with growing medium above and nutrient solution below

Science moment for kids: Explain capillary action — water molecules "climb" up the tiny spaces between cotton fibers, pulling nutrient solution from the reservoir up to the plant roots. Ask them where else they have seen this (paper towels, fabric absorbing a spill).

Step 4: Add Growing Medium

• Fill each planter container with perlite or vermiculite
• Leave about 1 inch of space at the top
• Make sure the wick is buried in the growing medium, ideally coiled in the center where roots will grow
• Perlite is lightweight and fun for kids to handle — it looks like tiny white pebbles

Safety note: Perlite dust can irritate eyes and lungs. Have kids wash hands after handling, and avoid letting them blow perlite dust around.

Step 5: Start Seeds Together

This is the most exciting step for kids:

• Make a small hole (1/4 inch deep) in the center of the perlite in each container
• Drop 2–3 seeds into each hole
• Lightly cover with perlite
• Or use starter plugs: soak in plain water, press seeds in, and nestle the plug into the perlite

Best seeds for kids:

• Basil: Sprouts in 5–7 days, grows fast, smells great, and kids can use it on pizza
• Lettuce (leaf varieties): Sprouts in 3–5 days, very fast-growing, edible quickly
• Microgreens (radish or sunflower): Visible growth within 2–3 days — instant gratification
• Chives: Easy and fun to snip with scissors

Step 6: Mix the Nutrient Solution

Keep it simple for kids:

• Fill a large measuring cup with clean, room-temperature water
• Add nutrients at quarter strength — herbs and lettuce in wick systems need very little
• Target pH: 5.5–6.5 (if you have a meter — otherwise, most tap water is close enough for this beginner setup)
• Pour the mixed solution into each reservoir container until it is about three-quarters full

Teaching moment: Explain that plants need food just like people do, and the nutrient solution is like a vitamin drink for the plant roots.

Step 7: Assemble and Place

• Set each planter into its reservoir so the wick hangs down into the solution
• Place the assembled planters on a sunny windowsill (south-facing is best)
• If no sunny window is available, a small desk lamp with a daylight bulb works for short-term growing

Step 8: Create a Garden Journal

Give each child a small notebook to track their garden:

• Day 1: Draw the planter, write what seeds were planted
• Day 3–5: Record when the first sprout appears
• Weekly: Measure plant height with a ruler, draw the plant, note any changes
• Harvest day: Record how the plant tastes and what they would grow next

This builds observation skills and makes the project educational beyond just gardening.

Nutrient Guide

Kids' wick gardens use very gentle nutrient levels:

Simple rule for kids: "One tiny squeeze of plant food in a big cup of water." Over-fertilizing is the most common mistake — less is more with wick systems.

Water refill: When the reservoir gets low, refill with plain water. Mix fresh nutrient solution only every 2–3 weeks.

Crop Suggestions for Kids

Estimated Cost

Educational Activities

These activities turn the garden into a hands-on science lesson:

Capillary Action Experiment

Before building the garden, demonstrate capillary action:

• Place one end of a cotton string in a cup of colored water
• Drape the other end over the rim into an empty cup
• Watch over several hours as water climbs the string and drips into the empty cup
• Ask: "How does the water go uphill?"

Light Experiment

Plant the same seeds in two identical wick planters:

• Place one in a sunny window and one in a dark closet
• Compare growth after one week — discuss why plants need light (photosynthesis)

Growth Tracking

• Measure plant height every 3 days and plot it on graph paper
• Calculate the average growth rate (inches per day)
• Compare growth rates between different plant types

Taste Test

When herbs are ready to harvest:

• Blindfold taste test: can they identify basil vs. mint vs. chives?
• Compare hydroponic herbs to store-bought herbs — which tastes fresher?

Tips & Troubleshooting

Tips for parents and teachers:

• Let kids make mistakes — a plant that struggles teaches more than a perfect one
• Celebrate every sprout, even tiny ones
• If a plant dies, discuss what might have gone wrong and try again — resilience is part of gardening
• Take photos at each stage so kids can see how much their plants have grown
• Have kids present their garden to family members or classmates

Maintenance Schedule

Daily (make this the child's responsibility)

• Look at the plants: are they growing? Any new leaves?
• Check the reservoir: can they see water through the container? If not, time to refill
• Write or draw one observation in the garden journal

Weekly (with adult help)

• Refill reservoirs with plain water or dilute nutrient solution
• Measure plant height and record in the journal
• Trim herbs — show kids how to pinch off leaves just above a leaf node

Every 2–3 Weeks

• Fresh nutrient solution — dump old reservoir water, rinse container, refill with fresh mix
• Check wicks — replace if they look stiff or discolored
• Harvest and enjoy — make a recipe together using the herbs or greens they grew

Monthly

• Assess which plants are thriving and discuss why
• Start new seeds to replace harvested plants
• Clean containers if mineral buildup is visible

Frequently Asked Questions

What age is appropriate for a kids' hydroponic garden project?

Children ages five and up can actively participate in building and caring for a wick system hydroponic garden with adult supervision. Younger children can help with planting seeds, decorating containers, watering, and observing growth, while older kids can take on mixing nutrients, measuring pH, and tracking data in a garden journal independently.

What is the easiest plant for a child to grow hydroponically?

Radish microgreens are the easiest and most rewarding first plant for kids because they sprout visibly within one to two days and are ready to harvest in just seven to ten days, which keeps young attention spans engaged. For a longer-term project that is still very forgiving, leaf lettuce and basil are excellent choices because they grow fast, tolerate beginner mistakes, and produce an edible harvest kids can enjoy.

Do kids' hydroponic gardens smell bad?

A properly maintained wick system should have no unpleasant odor at all. If you notice a bad smell, it usually means the nutrient solution in the reservoir has become stagnant or the growing medium is staying too wet, both of which are easy to fix by replacing the solution with a fresh batch and ensuring the wick is not delivering more moisture than the plant can use.

Can you use regular plant fertilizer instead of hydroponic nutrients?

It is best to use a nutrient solution specifically formulated for hydroponics because regular plant fertilizers designed for soil are often missing essential micronutrients like calcium and magnesium that soil naturally provides but an inert growing medium like perlite does not. Hydroponic nutrients contain the complete range of minerals a plant needs and are designed to dissolve cleanly in water without clogging wicks or leaving heavy residues.