Welcome to my potting shed! This is the column where I’ll share all my gardening hints and tips – and I’ll try to answer any queries you may have.

Q I’ve tried to grow Japanese anemones in the sunny border in front of my house but they just fizzle out. – Jenny Morrison, Alloa. A Your border may be too dry for them. Add lots of organic matter to the soil and water regularly until well established.

Cut out rasp stems that fruited this year and tie new stems to horizontal wires. If there are too many, remove some. Q My roses have been badly affected by black spot. Is there any way of getting rid of the disease without using chemicals? – D. McGill, via email.

A Removing and destroying affected leaves and pruning out stems with lesions will lessen the impact but black spot spreads so quickly it is unlikely that you will defeat it without using a fungicide at regular intervals.

Test if sweetcorn is ready to harvest by pinching a kernel. When this exudes a milky sap, the corn is ripe. Q Why do the apples on the tree that I grow as a cordon against a wall never ripen properly? – Mr Ian Turner, Stirling.

A It could be they are not getting enough sunlight. Cut back shoots more than 8” long to three leaves above the base and if there is any new, upright growth, take that out too. This way more light will reach the fruits and next year’s crop should also be improved.

Cut off foliage on maincrop potatoes three weeks before harvesting to firm the skins. Q Couch grass has invaded my garden. What’s the best way to get rid of it? - Linda Fraser, via email.

A You could use a glyphosate-based weed killer, but you’d have to be very careful not to get it on anything that you want to save. The alternative is to dig up all the plants, remove the weed from their roots and the soil, then replant.

Remove and destroy pelargonium leaves affected by rust and water plants from below to reduce the chance of the disease spreading to heathy foliage. Q I’ve always got a huge glut of plums. Can I freeze them? - Anna Tate, Fort William.

A You can. Wash, half and stone the fruits then spread on a tray and freeze. Once frozen you can store them, in the freezer, in bags or containers.

Remove suckers from roses, scraping back the soil to expose the join, then pulling off the unwanted growth.