Kratky Supplies

What you need

These Kratky supplies are all you need to start a Kratky garden at home.

• A dark container that holds water
• A lid or cover that blocks light
• Net pots
• Growing medium, such as clay pellets
• Hydroponic nutrient
• pH test kit or meter

A dark container that holds water

A wide-mouth mason jar is the most popular choice for one small plant. Buckets with lids and storage totes work for larger plants or several plants at once. If the container is clear, cover it with foil, paper or a sleeve so light cannot reach the water. More in Step 1: Pick a container.

A lid or cover that blocks light

The lid keeps light out and holds the net pot. Mason jar lids work well with a hole in the center, and some stores sell lids made for net pots. For buckets and totes, drill holes in the lid to fit your net pots.

Net pots

A net pot is a small plastic cup with slots so roots can grow through. Choose a size that fits snugly in your lid: small net pots for jars, larger ones for buckets.

Growing medium, such as clay pellets

Clay pellets, also called expanded clay or clay pebbles, support the plant and let air reach the roots. Rinse them before use. Rockwool cubes or seed sponges are handy for starting seeds and fit inside the net pot.

Hydroponic nutrient

Choose a nutrient made for hydroponics, ideally one labeled for leafy greens or general growth. Read and follow the label. More in Step 2: Add water and nutrients.

pH test kit or meter

A pH kit tells you whether the water is in the right range for your plant to take up its nutrients. Drops and strips are cheap and simple; a digital meter is quicker to read. pH up and pH down products adjust it. See Nutrients, pH and Safety.

Nice to have

• Seeds or seedlings (see Plants to Grow)
• A grow light, if you do not have a sunny window
• Measuring spoons or a small measuring cup for the nutrient
• Tape and a marker for marking the water level
• A notebook or phone notes for your grow journal

You may already have several of these at home. Start with one container and add more once you know what you like.

Where to find supplies

Garden centers, hardware stores and online shops sell net pots, clay pellets, hydroponic nutrients and pH kits. Mason jars are sold in grocery and kitchen stores. Many people start with a jar and lid from home and buy only the net pot, growing medium and nutrient.

A starter kit for one jar

• One wide-mouth mason jar and lid
• Aluminum foil or a dark sleeve
• One net pot that fits the lid
• A handful of rinsed clay pellets
• Hydroponic nutrient
• A lettuce or basil seedling

Supplies to reuse

Most Kratky supplies can be reused again and again. Wash jars, lids and net pots in hot soapy water between plantings. Clay pellets can be rinsed and reused many times. Seed cubes and sponges are usually single-use. Reusing supplies makes each new planting cheaper.

Store it safely

Keep nutrients and pH products in their original, labeled bottles, out of reach of children and pets. Keep glass jars where they cannot fall. More on Nutrients, pH and Safety.

What you do not need

You do not need a pump, an air stone, a timer or electricity for a Kratky jar. You do not need soil, or special tools beyond something to make a hole in the lid. That is what makes the Kratky method simple and inexpensive.

Supplies checklist

• Container and lid
• Light-blocking cover
• Net pot
• Growing medium
• Hydroponic nutrient
• pH kit
• Seeds or seedling
• Bright spot or grow light

Once you have these, turn to Step 1: Pick a container and begin. Keep everything together in one labeled box, so it is easy to find for the next planting.

What it costs to start

Most of the cost is in the first bottle of nutrient and a pH kit, and both last for many plantings. Net pots and clay pellets are inexpensive, and a jar may already be in your kitchen. After the first planting, each new container costs very little.

Buying tips

Check that your net pots fit your lids before you buy in bulk, and choose a nutrient sized for home use so it stays fresh. A small bag of clay pellets goes a long way in jars. If you plan to grow several plants, a pack of net pots and a larger bag of pellets is usually better value.