There is more than one way to make a plant collar. You can use a variety of materials as the basis for a plant collar, including: For consistent crops of tasty, high-quality caulis, it’s best to choose F1 hybrid varieties, and if you’ve ever had problems with clubroot disease, select resistant varieties. Look too for varieties with an RHS Award of Garden Merit (AGM), which shows they performed well in trials – see our list of AGM fruit and veg for RHS-recommended varieties of cauliflowers and many other crops. Brassica Collars offer a simple solution to stop the cabbage root fly, a notorious allotment pest that can cause serious damage to your brassica crops including broccoli, cabbages, cauliflowers, calabrese and brussels sprouts.

Cabbage root flies ( Delia radicum/Hylemya brassicae) have become problematic in my garden over the last few years. By early summer, I found myself losing at least half of my cole crop plantings to the little buggers. After doing a bit of research at the start of last season, I came up with a plan to keep cabbage root flies away from my plants, and it worked: cabbage collars. The circumference of the plant collar is 3.14 x D (pi times the diameter). The diameter is 2, so the circumference is about 3.14 x 2 or 6.28 inches. As well as traditional white or cream cauliflowers, there are varieties with striking purple, orange-yellow or lime-green heads for added ornamental appeal, both in the garden and on the plate. They generally keep their colour when cooked, unless boiled for too long. Because female cabbage root flies lay their eggs on or right next to the base of host plants, shielding the soil around the base of the plant is key to preventing this pest from becoming problematic. This is best performed within a few days of planting out susceptible cole crops. Typically I recommend covering cole crops with floating row cover to keep pests away, but in the case of cabbage root flies, covering them too early may actually trap newly emerged adult flies underneath the row cover, so instead I turn to making cabbage collars to protect my plants. I put a collar around each plant by late April because the first generation of adult flies typically starts to emerge in early May through June here in my Pennsylvania garden. Making Cabbage Collars What You’ll Need:For example, let’s say you wrap aluminum foil or plastic around a flat piece of cardboard and then curl it into a plant collar. The collar will now be protected from water and soil, so it will take longer to break down. Plastic Plant Collars cardboard, enough to create a 6- to 8-inch circle to go around each plant or recycled rounds of cardboard from frozen pizzas Summer varieties – usually sow indoors from winter to early spring. They are fast growing and form smaller heads, ready to harvest in four or five months. They are generally easier to grow successfully than later varieties, especially if harvested before any hot, dry weather.

Adult cabbage root flies look a lot like bristly houseflies only slightly smaller. They’re about 1 centimeter long with bristly hairs all over their gray bodies. This European species is now found across much of North American and up into southern Canada. If you are worried about damaging the seedling, you can cut a line from the outer edge to the center hole and wrap the brassica collar around the seedling that way. You will then have to staple the cut edges together for the collar to be effective. Just be sure that the collar opening can be enlarged as the plant grows. Gently place the plant in the hole, trying not to disturb the roots, then fill the hole repeatedly with water. Called ‘puddling it’, this also refills the hole with soil and ensures the plant is sitting in a large area of moist groundTo harvest, cut the stem with a knife, taking the head and a few of the leaves beneath it, to protect the curd.

Position the flaps so that they cover as much of the opening as possible, without damaging the plant stem. Toilet paper roll tube – once the toilet paper is used up, just take the cardboard cylinder and use it as a cutworm collar. You might be able to cut the roll into two or three collars. However, make sure you make the collars tall enough to deter pests and keep them away from your plants.

Starting at the center point, use the box cutter to cut four 1- to 2-inch lines that radiate out from the center point. Try to space them equally. Step 4