Row Covers
Lightweight fabric covers placed over crops to physically exclude flying and crawling pest insects while allowing light, air, and water to penetrate.
What it is
Row covers are made from lightweight, spun-bonded polypropylene or polyester fabric sold in various weights. Lighter grades are used primarily for insect exclusion while transmitting 85 - 90% of available light. Heavier grades also provide frost protection. They are a mechanical, chemical-free tool approved for use in any growing system.
What it does
Row covers create a physical barrier that prevents adult insects from reaching plants to feed or lay eggs. They are most effective when crops are covered from planting or transplanting before pests arrive. They simultaneously create a warmer, more humid microclimate that can advance growth by 1 - 2 weeks, and protect against some foliar diseases spread by flying insect vectors.
When to use
Install row covers at the time of sowing or transplanting, before any pest pressure is observed, for maximum effectiveness. Use over brassicas from planting to protect against cabbage butterflies and flea beetles. Cover squash, cucumbers, and courgettes at planting to exclude cucumber beetles and squash vine borers, removing at flowering to allow pollination.
When not to use
Remove row covers once plants come into flower if the crop requires insect pollination, or when temperatures under the cover consistently exceed 86°F, which can reduce fruit set. Inspect the undersides of covers regularly - if pests were already present at installation, the cover can accelerate their population growth in an enclosed environment.
How to apply
- 1
Prepare the bed and sow or transplant crops before installing covers, or install on the day of planting.
- 2
Lay the row cover fabric loosely over the bed, allowing enough slack for plants to grow upward without the fabric pressing on them.
- 3
Secure the edges firmly to the ground using soil, sandbags, staples, or purpose-made fabric pegs all the way around to prevent pest entry at ground level.
- 4
Check under the covers every 5 - 7 days for any pests that may have been present before installation, and inspect for ventilation on warm days.
- 5
Remove at flowering for pollinator-dependent crops, or at any time pest pressure has passed and temperatures under the cover are manageable.
Garden, by Willowbottom recommends only organic, wildlife-friendly solutions. No synthetic pesticides, no harmful chemicals - ever.