Growing cucumbers indoors – complete step-by-step guide

Quick overview: how to succeed with your cucumber curtain

1. Prepare & sow – indoors, Feb–March (or year-round with grow light)
2. Replant when the plant has 2–3 pairs of leaves.
3. Tie up the window and shape your cucumber curtain
4. Maximize your harvest with proper watering, nutrition and harvesting
5. Act quickly on pests to keep the plant healthy

Step 1: Preparation and sowing

This is what you need

• Cucumber seeds
• Growing briquettes or small pots
• Dish with rim
• Transparent cover (plastic film, plastic bag with holes, glass dome or mini greenhouse)
• Good quality potting soil
• Pot of at least 5 liters with drainage holes + barrel

How to sow cucumbers

1. Sow indoors from February–March when the light returns. With a grow light you can sow all year round.
2. Sow one seed per growing briquette or in a small pot with potting soil.
3. Cover the seeds with something transparent that lets in light but retains moisture.
4. Place warm – the seeds germinate best on underfloor heating, a heating mat or above a radiator.
5. Water with lukewarm water . The soil should be moist, but not wet.
6. After 5–15 days, the seed germinates. The plant then needs a lot of light.
7. Place in a bright window (at least 6 hours of sun) or use a grow light for 13–15 hours/day.
8. Check daily – growing briquettes dry quickly.

Tip: Seeds can germinate at different speeds. Be patient!

Step 2: Transplanting

When the plant has 2–3 pairs of leaves (4–6 leaves in total) , it is time to repot. You will often also see roots starting to grow out of the briquette.

How to replant

1. Choose a pot of at least 5 liters with drainage holes.
2. Feel free to add Leca balls to the bottom for better drainage.
3. Fill with potting soil and water through the soil.
4. Plant the cucumber at the same depth as before (not deeper).
5. Plant one plant per pot .
6. Place in a bright and warm place, preferably in a sunny window.
7. Water as needed and start nutrient watering once a week .

Step 3: Create your cucumber curtain (tie up the plant)

When the plant starts to grow rapidly, it is time to shape the cucumber curtain itself in the window.

How to tie up the cucumber curtain

1. Place the pot next to the window.
2. Cut a string (e.g. hemp thread).
3. Tie the string carefully around the plant.
4. Attach the string to the top of the window (nail or hanging tape).
5. Help the plant to wind its way up the string.
6. Keep the soil evenly moist.
7. Nutrient water once a week.

Step 4: Maximize your cucumber harvest

When the plant begins to bloom with yellow flowers, the harvest is near.

• The first cucumbers may shrivel – this is normal.
• Cucumbers are largely made up of water – regular watering is crucial .
• It is advisable to water from below to reduce the risk of pests.
• Continue nutrient watering every week.
• The cucumbers are ready at 10–15 cm , when they are shiny and springy.
• Harvest often – it will produce more new cucumbers.

Step 5: Fight pests in time

Pests can affect anyone. The sooner you act, the easier it is to save the plant.

Common signs of vermin

• Small black flies (mourning gnats)
• Sticky leaves
• Discolorations or spots on the leaves

Effective methods

• Sticky traps
• Replace the top layer of soil
• Shower the plant with lukewarm water
• Spray soapy water (1 dl soap + 9 dl water)
• Neem oil
• Myrnix

Frequently asked questions about cucumber curtains

When should I sow cucumber curtains?

From February–March indoors. With a grow light you can sow all year round.

When is it time to replant?

When the plant has 2–3 pairs of leaves or when the roots begin to appear.

How big a pot is needed?

At least 5 liters, always with drainage holes.

When can I harvest the cucumbers?

When they are shiny, elastic and about 10–15 cm long.