Intro: Cruciferous Cages to Prevent Cabbage Moths
Never have to spray your broccoli, cabbage, kale, or other cruciferous vegetables again! These cages prevent the cabbage moths from invading your plants without shading them too much. You can have easy access to it through the lid but you don't have to remove it to water or to see how it's doing. They are also tough enough to last many years.
Step 1: Supplies Needed
Hardware cloth - 1/8" or 1/4" square holes, 30" to 48" wide
36" Aluminum screening for lids
cardboard or wooden circle template for lid
22 gauge florists wire
Heavy gauge wire (optional)
Step 2: Cut Lid
Make a cardboard circle template for the lid. Mine is 27" wide and made of plywood but it is not necessary to be made of plywood. I found this width to be a good size for any of my vegetables. Cut the aluminum screening about 2 inches wider than your template with the tin snips. It doesn't have to be perfect unless you are worried about appearance.
Step 3: Cut Length of Hardware Cloth
Cut the length of the hardware cloth to make the cylinder cage using the tin snips. You will need to do a bit of basic geometry for the right length. For the cylinder to have a 27" diameter, you need to multiply 27" x 3.14(pi) + 1" overlap = 7'2". My first cages were made with 30" width (which is the height of the cage) but I found that broccoli and kale will outgrow this by the end of the season. I bought 48" but these are too wide to work with and I ended up cutting off about 6". In hindsight, I wish I would have looked harder for 36" width. My first cages were also 1/8" square hardware cloth and this worked well over the years. Recently, I bought the 1/4" square and so far, so good on still keeping the moths out.
Step 4: Sew Together and Add Lid
Using the 22 gauge wire, sew the width together. I used green colored wire so I could see what I was doing easier plus it's what I had on hand. Using a clamp on one end will help you manage it. It does take some patience! Stand it up and optionally, you can tie a piece of heavy guage wire on top with the thin wire for stability. This does help to keep the lid on but it will take more room to store since you can't collapse it.
Mold the aluminum screen lid to the top. You can make the lid out of the hardware cloth but the ends are sharp and it's difficult to mold to the top. The aluminum screening is much easier on the fingers.
Step 5: Stake Cage Over Your Plant
I use two stakes wired to the cage to hold it in place in the garden. A few times over the season, I take the cage off to weed but if your arms are long enough, you can reach down from the top to weed. Above are two pictures of cabbages. One that grew in the cage and one that grew out. It really works! I still cook my broccoli and inspect thoroughly for worms and it may be possible for a moth to slip in when you have it open, but I have had good results with it. The shade of the cage may keep it from growing as rapidly but it also keeps it from flowering sooner.
The cost of making a cage can cost anywhere from $10 - $20, which can be cost prohibitive. However, take into account that you don't have to worry about spraying toxic chemicals and the time you will save eliminating this chore.