pigeons
Unfortunately, pigeons are brassica connoisseurs, so if they have found your patch you might need to protect your young kale seedlings with netting. Luckily, they seem to lose interest once the plants mature, so with luck you can remove the netting once you want to start picking the crop yourself.
cabbage root fly
Cabbage root fly can be very damaging to young transplants as they eat away at the roots and weaken the plants. The first generation usually emerge in April, just as you are planting out. If you practice crop rotation you will break the cycle of last year’s pupae hatching out into the next crop.
You can also deter the adult flies from laying their eggs close to the root by placing a brassica collar or circle of carpet underlay around the stem. Enviromesh or horticultural fleece will also prevent the adults getting anywhere near your plants.
cabbage white caterpillars
Cabbage white caterpillars arrive a little later in the season, in June or July, with the white butterflies laying their bright yellow eggs on the underside of the leaves, and the stripey green caterpillars emerging soon afterwards, ready to strip whole plants to a skeleton if you are not sufficiently vigilant.
Rubbing out the eggs as soon as they are laid is the least gory solution. Once they have hatched into hungry caterpillars the squashing is messier, but essential if you are going to get a decent crop.
The good news is that kale will recover from an attack, giving you a later crop in the winter once it is too cold for the caterpillars. Netting, Enviromesh or horticultural fleece will in theory keep the butterflies out, but they are remarkably devious, finding the slightest chink in your armour. If they can’t physically squeeze in they will actually lay their eggs through the netting if it’s touching the leaves. Of course, the netting keeps you out too, so you can neither squash the eggs nor pick the crop, so unless you make a walk-in brassica cage, you will probably be frustrated.
cabbage whitefly
Adult whiteflies are active throughout the year, overwintering on your kale and if you are unlucky, flying up in clouds as you pick the leaves. A mild infestation will not harm the plant, and they are easily washed off in salty water once you get them home. But a really bad attack will damage the plant and lead to sooty moulds appearing on the leaves. Spraying with an insecticidal soft soap or SB Plant Invigorator might be your only option.
mealy cabbage aphid
These aphids hide under the leaves in dense greyish-white colonies. Scrape them off if you see them appear, and then rely on their natural predators ladybirds, hoverflies and lacewings to come to your aid and finish the job.
clubroot
This is an insidious soil borne fungal disease that does exactly what you might expect – it turns the roots into a contorted useless stump, and causes the plant to wilt and eventually die. It is important to buy only plants from a reliable source, or raise your own from seed grown in fresh bought-in compost. Once it is in the soil it is very hard to eradicate, although liming prior to planting out will help, and a strict rotation is paramount.
why is my kale not growing?
This could well be caused by the aforementioned clubroot or cabbage root fly. Pull up the worst looking plant and see if you can see anything amiss below ground. There could still be time to start again with some new seed in fresh ground.
why is my kale plant turning yellow?
There are bacterial infections that can cause yellowing of kale leaves, also the mealy cabbage aphid (see above) can create yellow spots, but the most likely cause is stress. If you have left seedlings in their small pots for too long, they will have run out of food, so planting them in the open ground will definitely help. If you are growing them on to adulthood in a container they also might be struggling for enough water and nutrients. My favourite pick-me-up for hungry looking plants is a foliar spray of seaweed, you will soon see a huge improvement.
what's eating my kale plants?
The most likely culprit is the cabbage white caterpillar or pigeons both of which can soon strip the leaves to a depressing skeleton. If you are seeing little pin holes in the leaves, this is more likely to be a flea beetle attack. These shiny black beetles jump up from the soil surface when the warm weather comes and will attack your seedlings. Keeping the soil moist will help deter them until the plants are big enough to fight the battle.
why is my kale plant wilting?
This will either be caused by drought, overwatering or root damage. Once you have ruled out the first two (by watering or withholding water), pull up the worst affected plant and inspect for either clubroot or cabbage root fly.
why are my kale seedlings leggy?
Most plants get leggy (elongated or etiolated being the more technical term) if they are struggling for enough light. Make sure you haven’t sown the seed too thickly in the pot or seed tray. Just a pinch of the tiny seeds, sprinkled about 2cm apart will be plenty. Then thin them out to 4cm apart and ensure they are growing in a sunny part of the greenhouse or windowsill (don’t forget to add the thinnings to your salad!).
why are my kale seedlings falling over?
Most of the brassica family are very shallow rooted, so they need to be planted deeply into firm ground to prevent root rock. They are often top heavy too, with their extravagant lush leaves being battered by the wind. It can be worth staking them with a cane if your garden is particularly windy, and this should keep them upright a bit longer.
