Sewing Insect Netting Curtains for Polytunnel and Greenhouse Doors

Machine-sewing fine mesh netting is tricky, but a custom insect curtain for my polytunnel door was essential to exclude wasps, bees, large flies, and pigeons while maintaining ventilation. Here's how to sew a durable, well-fitted panel using fine insect mesh.

1. Choosing and Measuring Netting

Select outdoor-rated fine insect netting (I used carrot-fly mesh). Measure the opening, adding 1–2 inches per side for hems. Consider extra width to secure sides—straight-hanging curtains gap in wind, letting insects in. Hemming prevents fraying; elastic tape in the top hem allows tying to the frame.

2. Pinning Double-Folded Hems

Fold raw edges ¼–½ inch, fold again to encase, and pin. Ironing (with a cotton press cloth, dry iron, medium heat, no steam) works better than pins, which slip out of fine mesh. Hem sides and bottom; top edge may not need hemming if stiff.

3. Sewing Machine Settings

Use a standard foot, zigzag stitch (stronger than straight). Settings: 1.2 mm stitch length, 5 mm width, Sharp 60/8 needle for fine fabric. Stitch slowly along the double-folded hem.

How to Sew a Double-Folded Hem

4. Zigzag Stitch Result

Not pretty, but exceptionally strong and fray-proof.

5. Securing the Top Edge

Create an elastic casing: lay elastic tape 1 inch below top edge, fold netting over it, pin, and zigzag-stitch just under the elastic—don't stitch through it. Leave excess elastic at ends for tying to the frame.

6. Making an Elastic Hem

The elastic casing runs the full width, secured with pins at corners for hanging.

7. Adding Elastic Side Tabs

Optional: sew 3 elastic tabs per side to secure the curtain laterally, preventing wind gaps. Switch to a universal 80 needle for sewing through elastic.

8. Installed and Working

Elastic ties at top and sides hold the panel taut. One side uses Velcro on the tabs for easy access. Door stays open for ventilation; insects stay out.

These techniques adapt to windows and vents too. Fine mesh gives you control over what enters your growing space while keeping airflow high.

Image Credit: All images on this page belong to the author, Marie Williams Johnstone.