Prune and plant
March rose notes
Continue to summer prune. Cut back those long, untidy canes. It will make winter pruning easier.
Water regularly in the early morning or evening a least twice a week.
Make sure the soil around the roses hasn’t become compacted. Carefully loosen it with a fork or hoe. Sprinkle a handful of potash around the dripline and gently fork in to ensure strong canes in spring.
Look closely at foliage. Unless you are a manic sprayer it is probably marked with black spot by now but, if the leaves are yellow, it could be due to a magnesium deficiency in the soil. To combat this, dissolve a scant teaspoon of epsom salts in a litre of water and pour around the dripline.
Deadheading is optional this month. There is no point in deadheading roses that finish flowering at the end of summer but with roses that keep on blooming until winter, deadheading will keep them to task.
It’s not too early to order new roses from specialist nurseries. Popular varieties sell out quickly.
Summer crops are still producing
But no matter how warm it feels where you are, they’ll all be over soon! As you pull out your tomatoes, peppers, beans and eggplants, fill any gaps with carrots, beetroot and radishes, which can all be sown direct now.
Swedes and turnips can too – if you live somewhere that offers a cold enough winter to sweeten them up. Otherwise, plant spinach or silverbeet seedlings.
Sow some peas and broad beans as well. They are nitrogen fixers so they are a good option to grow in a bed where you’ve just grown leafy crops.
Brassica seedlings can be planted but protect them from cabbage whites! These rapacious butterflies will still be on the wing, so cover seedlings with a physical barrier such as a net curtain or horticultural mesh.
Fill gaps with green crops
A Canterbury study found that green crops need to be sown as early as possible to maximise their effect on the soil.
The type you use depends on what you’ve been growing and what you plan to grow. Mustard is a brassica, for instance, so don’t use it as a green crop in a bed where you plan to grow cabbages and broccoli.
Green crops keep down weeds, add organic matter to the soil, help retain water and can also be used to ‘‘sterilise’’ your soil to a degree if you’ve had a problem with a soildwelling pathogen – mustard and daikon radishes both have a natural biofumigant effect (although be aware they’ll kill any good guys in the soil).
Daikon are a good choice if you want to break up compacted soil – leave them in the ground to rot and they’ll leave the holes they’ve drilled. – compiled by Barbara Smith