During warm and sunny weather, cabbage white butterflies can visit your cabbage plants. Female butterflies lay their eggs underneath the leaves of the plants. After some days to weeks there are caterpillars that eat a lot of plant material. The big caterpillars often “hide” in the white cauliflower or in the broccoli. Or between the leaves of Red Cabbage, Savoy Cabbage or White cabbage.
When preparing the cabbage in the kitchen, one should take care of searching and removing all caterpillars, otherwise you’ll have an unpleasant surprise on the plate.
Each day you can inspect the leaves of cabbage plants for eggs or caterpillars and remove them.
I think it’s easier to grow the cabbage plants in a “buttefly proof” cage. In this post there is a detailed description of the “cabbage cage”
The cabbage cage consists of these parts:
- At the sides there is metal wire netting. It has about 0.5 inch square mesh. Netting highth is about 63 cm (25 inch).
- In each corner there is a (metal) tube in the soil. About 25 inch of each tube is above the ground. The tubes support the wire netting.
- A rectangular frame made of wooden laths. At each corner there is a pen. Each pen fits in a tube in the soil. This improves the robustness of the cabbage cage.
- Nylon or plastic cord. It has been wrapped around the laths and through the meshes of the wire netting. It makes the cage “butterfly thight”.
- Another rectangular frame made of wood. It acts as a lid. In the frame there is a net with small mesh so butterflies can not pass this net. The lid lays with 4 screws on the rectangular frame. The lid can be removed or it can be opened. A wooden lath supports the lid while opened.
Here is a description of the 5 parts. There is information about making, remodeling or adaptation of the parts.
1. Metal wire netting
On this photo the wire netting is put on the garden soil. When 4 tubes are in the garden soil, wire netting is mounted around them.
These tubes are made of aluminium. They have been used at roll-up blinds. The tubes are about 1.5 inch wide and 4 feet long.
Maybe you can buy this type of tubing at a D.I.Y. shop. P.V.C. tubing can also be used, I think.
3. Rectangular frame
Here a photo of the rectangular frame. It has been made of wooden laths of about 2 inch wide and 1 inch thick.
At each corner there is a plastic connecting plate and a pen.
The connecting plates are triangle shaped pices of polypropene. They have been sawn from a plastic cutting board of about 5/16inch (8 mm) thick.
In each plate there are 4 holes. The nylon or plastic cord is put through these holes during wrapping.
After assembling, at each corner, a small piece of lath has been sawn (hacksaw). This forms some space between the laths, so rain-water can flow away.
Instead of plastic connecting plates you can use metal corner braces. On this photo the rectangular frame with metal corner braces (design 2009). Metal connecting material will rust and is not so robust as polypropene.
A frame with metal corner braces is not so strong and form-retaining as with plastic plates.
Plastic plates are also useful when laying the frame on the 4 tubes in the soil. More about this at “Assembling the cage”.
For each pen you use a long wood screw, a metal nut ring and a piece of hose.
The wood screw with ring and piece of hose is screwn through a hole in the plastic plate into the wooden lath.
On this photo you see the pen fixed in the wooden lath.
Temporary remove the wood screw next to the pen at all 4 corners of the frame. This screw is not in the same lath as the pen. Now you can fold the frame. The folded frame is easy transportable. Later unfold the frame and mount all 4 screws again.
Four pieces of nylon or plastic cord to fix the metal wire netting to the frame.
The “lid” has been made of wooden laths of about 1 1/4 inch x 1 inch. Laths are connected to each other with metal connecting plates.
At the inner side of the frame, so at one side of each lath, there are iron nails. Distance between nails is about 3 inch. Nails will be used to fix the nat later.
The nails are in the wood sloping so later the net will not slip away so easy. The nail head is nearer to the plate than the position where the nail enters the wood. All nails are sloping in the same direction.
When you remove 1 screw in each plastic connecting plate (the right screw), you can fold the lid frame. So easy transportable.
This net has small mesh size. The butterflies will not pass.
The sticker of the net.
Assembling the cage.
When folded, open the frame. Lay the frame on the garden soil. Put in the 4 screws that have been removed prior to “folded transport”. Do not tighten the screws.
Next step is adjusting the frame so making the frame at right angles again. Do this by tightening a nylon string from one corner to the opposite corner.
From one corner
..to the opposite corner.
Use a cord with a loop. Put the loop around the pen. Put the other side of the cord to the opposite corner, tighten and determine the distance. Put a small knot in the cord or keep it fixed between thumb and index.
Then determine in the same way the distance between the 2 other opposite corners. Most of the time this distance is some shorter or longer than the first determined distance. This means that the frame is not rectangular, so it has no 4 right angles. Then “change the form” of the frame a little and determine both distances again. Continue until both distances are (almost) equal. Then fix all screws in the 4 corner plates.
Lay the frame on the garden soil, at the place where the cage must be built.
When the frame is at the right position, push at each corner the pen into the soil. Then take away the frame. Now you have 4 small holes in the garden soil at the position of the 4 tubes.
This metal tube has a diameter that is bigger than the tubes of the cage.
Hit the big metal tube in the garden soil at each small hole. Use a wooden hammer or put a wooden lath on top of the tube and hit with a metal hammer to overcome damage of the tube. Take the tube out of the soil and tap against it to remove the soil from it. Repeat this until the hole in the soil has the same depth as the length of this big tube.
Lay the frame on the garden soil and check if all 4 pens fit into 4 holes in the garden soil. Then remove the frame again.
Put one metal tube in each hole. Hit each tube into the soil until it is about 2 feet above the soil. Use a wooden hammer. Or hit with a metal hammer while putting a wooden block on top of the tube. This is to prevent damaging the tube.
Put te frame on the metal tubes;
- put (at 2 adjacent corners) the plastic connecting plate on the tube.
- lift the frame at the 2 other adjacent corners and put the plastic plates on the tubes.
- now 4 connecting plates of the frame is on 4 tubes.
- at each corner put the pen into the tube.
- when needed, bend a tube a little bit aside to have the pen fitting into the tube.
Keep the frame on the 4 tubes until you start working the soil (digging).
Take the frame from the 4 tubes and lay it on the soil in your garden. The 4 tubes remain in the garden soil. Work the garden earth while tubes are in the soil.
Dig the soil around and between the tubes. This works well.
After digging, lay stepping boards on the garden soil, so earth will not be treaded down.
Make a small furrow between the 4 tubes. In this furrow a small part of the metal wire netting will be digged in.
Put the metal wire netting around 3 tubes. On the photo the netting has been put around all tubes exept the left rear tube.
Dangle the “last tube” (rear left) in the garden soil. Then take this tube out of the soil.
Put this tube at the “inner side” of the wire netting. Use this tube to push against the wire netting until the tube is above the hole in the soil. Then put this tube in the garden soil again.
The metal wire netting is now around all 4 tubes. Push the lower part of the wire netting into the small furrow.
Put the frame on the 4 tubes again. The pens are next to the tubes.
At each corner, put the pen into the tube.
At the corners it can happen that the frame is somewhat higher than the top of the metal wire netting. Then carefully hit the corner of the frame until the tube is at the right depth. Again use a wooden hammer or a wooden block on the frame when using a metal hammer.
Then put earth into the furrow to fix the lower part of the metal wire netting.
Wrap nylon or plastic cord through the upper meshes and around the laths. So the wire netting fits to the laths.
Put the lid on the frame. When you do this without any help from another person, put it “skew” on the frame. Then turn the lid carefully until it is correct on the frame.
When the lid is stuck (jammed), you can make the lid a little bit smaller. Take 2 adjacent screws out at one corner. Shift the connection plate on the lath and put in the screws again. Chipboard screws can be put in wood without predrilling. Bit you may drill or use a thinner chipboard screw. And then put in the original chipboard screw.
Fix 2 laths slanting on the lid. When the lid is still stuck (jammed), you can eliminate stucking by screwing the laths “somewhat further”. So push a lath of the lid more inside and fix the slanting lath then.
Take the lid from the tubes and put it on 3 big flower pots at an empty area in the garden.
You better put the net in the lid above the slanting laths. The net will not bend so easy on the cabbage plants. When the net is lying on the leaves of a cabbage plant, the butterfly is able to put eggs on. These can grow to caterpillors.
Tighten the net a little. Then fix the net to some nails at 2 corners of one short side (on the photo at the right side).
Fix the net behind 2 screws at a long lath (at the bottom of the photo).
Fix the net to some nails at 2 corners of the other short side (on the photo at the left side).
Tighten the net and fix it to all nails in 1 long lath and 2 short laths. On the photo visible at the right, left and lower side.
At the other long lath there is too much net material. On the photo at the top. Tighten the net a little. Again and again, at a part of the net, cut the surplus of the net and fix it to the nails.
Cut the surplus net at the left side.
Check if the net is fixed to all nails. When not, fix the net to the “empty” nails.
Put the lid on the frame to close the cabbage cage. Lay the supporting lath on the lid when not used.
On this photo the cage has been opened at one side. The lath supports the lid.
This photo from 2011 shows the v-shaped end of the supporting lath.