How to Protect Your Brassica Plants from Pests

Why Should I Cover My Garden in the Spring and Fall?

In many areas, spring and fall are the perfect times to grow Brassicas. Unfortunately, along with growing Brassicas comes pests like the imported cabbageworm, and the best way I have found to avoid any damage from those pests is by covering your plants.

I first heard about this method at a Mother Earth News Fair, and after trying it, I’m a huge fan. I honestly think my family and I wouldn’t have had any greens one fall if it weren’t for me covering them with tulle after transplanting them outside.

See for yourself in this video. The difference in the uncovered and covered plants is pretty convincing, right?

NP | Backyard Garden Tour | October 2016

So how can you use this method, too?

How Can I Protect My Garden in the Spring and Fall?


First you need a frame – something to hold up the tulle, row cover, lightweight garden cover or old sheets, so they aren’t lying directly on top of your plants.

If it’s time to plant and you need more time to set up your frame, go ahead and lay the cover right on top of your plants. It’s important to cover your plants as soon as they are planted to prevent eggs from being laid on them. You don’t want to trap eggs inside the cover, because once they hatch, the larvae will devour your plants.

Eventually though, you want to set up a frame so you can get the cover you are using off of your plants. Your plants will need the room to grow, and they will want the space to dry out after the morning dew and rain.

When I first covered my plants, I laid tulle right on them. Then, I set up some rebar and PVC pipe “hoops” to keep it off the plants as they grew taller and spread out.

Plant Under Rebar, PVC Pipe and Row Cover

Rebar + PVC Pipe

This is a great option if you want a DIY project or need a less expensive option.

It’s what I used in my raised beds. I keep them in the ground all year, removing the cover and putting it back on when needed.

Originally, I set it up so I could garden year-round, protecting my plants from freezing temperatures, but I quickly learned how much it come in handy for protecting Brassicas from pests as well.

Garden Hoops

These can be purchased in a tall version, giving you more flexibility with different plant heights,  and a short version that is ideal for a 3 foot wide bed, providing enough room for 14” tall plants.

Garden Cover


You can find tulle at a local fabric store or buy it online.

I used some that I had left-over from a sewing project and bought some light green tulle to add to it when I needed to cover the entire bed.

Can’t find the right size? You can sew pieces together to create the size you need – that’s what I did, and it worked great.

Lightweight Garden Cover or Row Cover

You can also lay down a lightweight garden cover to protect your plants. The one I linked to allows light to shine through and protects your plants down to 28°F.

These are sometimes called floating row covers as well because they are fairly easy to add and remove from your garden beds. Personally, I drape mine over the rebar and PVC pipe and then hold them in place with some concrete pavers because we already had those on hand. You could use pavers, logs or garden staples to hold your cover in place.

Food Tents

These are designed to protect your food and drinks from bugs when eating outside, but they can serve the same purpose for plants by protecting them from pests as well.

This is a great solution if your plants are spread out around your garden and you don’t need to cover a very large space.

However, be mindful about the dimensions, keeping in mind how tall your plants will grow when mature. These tents are made to cover up to 8” height which would work for mustard greens, radish and turnip, but your kale, Swiss chard, collard greens, broccoli and cauliflower will quickly outgrow them.

Old Sheets or Fabric

No need to get fancy. If you have a tight budget or are just looking to use something around your house – old sheets and fabric can do the trick, too.

If you do go this route, be sure to use light colors and not lay them directly on the plants. Sheets and fabric tend to dry out much slower and could cause damage or invite disease.

Combination of Hoops and Cover

This Gardman Netting Grow Tunnel comes with both the galvanized wire hoops and the netting you need for a quick set up.

It’s a great option for in-ground beds in rows and/or a speedy set up.

Greens and Flowers Harvested from the Garden

Wrap Up…

…your spring and fall garden plants to protect them from pests like the imported cabbageworm.

The biggest garden help for me during these growing seasons is to use a cover to protect my plants while they mature. It allows them to get a strong start, and it allows my family to eat off of them all season long!

Just be sure to measure your growing space before purchasing materials to cover it. And remember, this works so well for Brassicas because they don’t need pollination. If you want to try this with other plants, be sure to uncover them once they flower.

2 thoughts on “How to Protect Your Brassica Plants from Pests”

  1. I use tulle as well! Draped over hoops made from bent electrical conduit (it’s cheaper than PVC). I did just buy some micromesh off Amazon, because there is always a fly that gets in there, and then my cats try to attack and rip the tule. I’m hoping this micromesh will last more than a few season.

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