Kale and broccoli are two of our favourite brassicas and they’ll be at their tastiest best when freshly picked in the garden. I must add a new boy on the block: flower sprouts, or sometimes rather coquettishly called kalette.

This F1 kale/sprout hybrid produces a succession of unbeatable side “tufts” of delicious little leaves.

As with the rest of the brassica brigade, our tasty favourites appeal to pests as well as us, but a few simple barriers will foil them.

Our prime rivals are: slugs, cabbage root fly and cabbage white butterfly larvae.

You could add wood pigeons to the mix and grazing deer if you live in the countryside like me.

As we know to our cost, slugs are keen herbivores – the smaller and tastier a leaf, the better.

Our seedlings are at risk from the moment of germination: I always put seed trays and freshly pricked out young plants safely on a table. When planted out, they need some more protection.

Large yoghurt pots, with the base cut off and a smear of vaseline-type sticky substance round the perimeter, does help. Beer traps and ferric phosphate organic slug pellets also work. Following a recent trial, Which? Gardening recommend Westland Organic Slugstop Barrier pellets, available from B&Q.

As a general rule, molluscs ignore larger, tougher leaves, but cabbage root fly guarantee a brassica’s lingering death as the fly’s larvae consume their hosts’ roots.

So when pricking out into pots or planting in the open ground, place cabbage collars round the base of stems to stop the fly laying its eggs near plants.

Otherwise you’ll see a healthy young plant’s leaves wilt and turn purple. There’s nothing worse than pulling a root-free plant out of the ground.

Cabbage white butterflies are next on the scene, intent on laying eggs on the underside of leaves: small whites lay one or two eggs, large whites an overly generous clutch.

Once hatched, the larvae consume most of their hosts’ leaves. Again, the solution is simple.

When you first see the butterflies flitting around, cover plants with insect mesh or, preferably, insect net but not fruit cage net.

Keep the mesh off leaves as butterflies will lay eggs through the mesh, and keep mesh firmly pegged down.

The determined insects will be sure to find and use any small gaps. Remove mesh in the autumn when you see no more butterflies.

Like me, you may have to replace the mesh with fruit cage net to keep pigeons and deer at bay.

Plant of the week

Malus toringo ’Scarlett’ is a small, spreading crab apple tree growing to about 3m. In spring it has rich pink, fragrant flowers that make a beautiful contrast to the paler shades of most apple blossom. The emerging foliage is deep purple but greens as it develops and the tree bears small, crimson purple apples in autumn.