Diarmuid Gavin on the top garden gripes and how to solve them

Weed control

‘Help! my garden is full of weeds — dandelions, daisies and bindweed. I don’t like using chemicals. Where do I start?’

You can cover the area with layers of old cardboard and top this with some mulch. The cardboard will gradually break down but, in the meantime, will exclude light so weeds can’t flourish. However, this can take up to a year and may not be practical, depending on the size of your garden.

Otherwise you just need to get out there and dig it all out by hand. Just like housework, some people find this very therapeutic; others hate it. After that, you need to get planting. Nature abhors a vacuum, and new weeds will colonise quickly if you don’t fill the space. Regular weeding thereafter will keep things in control. Having the right equipment will help enormously here — use long-handled hoes and forks for digging out those perennial toughies.

Slugs and snails

‘Slugs and snails are the bane of my life. Can you give me any tips for controlling them?’

In a wet country such as ours, slugs and snails are the number-one pest problem for gardeners. I don’t like what they do to hostas but, in general, I can live with them. They are a valuable food source for frogs, hedgehogs and lots of birds so, in the wildlife-friendly garden, they are useful.

However if they are eating everything in their path, something needs to be done. You can pick them off by hand and relocate them if you don’t like killing them. They love to munch on fresh new foliage so you can protect new plantings by the use of plastic collars, layers of grit and eggshells or copper rings — the copper gives them an electric charge apparently.

Finally, you can use a biological control in the form of nematodes — this comes in powder form which you mix with water and drench the soil with. These parasites will kill off the resident slug population in that area.

Vine weevil

‘My plants are being eaten by something. My photinia leaves are covered in little notch-shaped bites and the whole plant is looking unwell. I’ve noticed it in some other shrubs in my garden so whatever it is seems to be on the move. Help!’

This is the dreaded vine weevil — a small creature that can wreak havoc in your garden, so you need to take action. The adults are munching on the leaves but it’s the larvae in the ground that are doing the real damage, munching on the roots of your plant.

The best way to tackle this is with nematodes such as Nemasys Vine Weevil Killer, which you should apply as per directions, usually when the soil is warm enough in April and September. You can also try and catch the adult culprits at night-time by inspecting the leaves with a torch and removing them. They have their natural predators such as frogs, hedgehogs and birds, so the more wildlife-friendly your garden is, the more likely nature will balance everything out.

Rose blackspot

‘I love growing roses but have a real problem every year with blackspot. What do you recommend?’

Blackspot is a fungal disease that looks bad and weakens the plant. Like many fungi, it flourishes in damp conditions, which is pretty standard weather on this island. Roses are best in an open, airy, sunny position, and the stronger they are, the better they will fight infection, so adhere to good watering, feeding and pruning regimes.

Once you have it, and it’s easy to spot with its dark lesions and spots, you need to spray regularly in the growing season. This can be with an organic oil or baking soda mixed with water and some liquid soap. You could also try alternating sprays as the fungus tends to build resistance. Remove the infected leaves in winter from the plant and destroy.

Plant of the week

Helleborus ‘Viv Luisa’ Hellebores provide early nectar for pollinators — I observed an early bumblebee tumbling out of their petals last week. Ideal plants for growing under deciduous trees where they will flower through late winter and spring with their nodding, cup-shaped flowers. Grow in fertile, moist but well-drained soil. Viv Luisa is a beautiful variety with regal maroon purple double flowers.

Today’s News in 90 Seconds – February 21st

Reader Q&A

I bought a miniature Christmas tree in a pot for the festive season. How do I look after it now as it’s beginning to look a bit unwell and brown at the tips? Melanie

Your small tree is probably a dwarf variety of fir or spruce and will be much happier outdoors in its natural environment. Even though it’s small now, it could well grow into something much bigger, so decide whether you want to take that chance and plant it in your garden. Or perhaps you’d like to keep it in a pot outdoors so that it can be brought back inside next Christmas as a temporary indoor decoration. If it remains in a pot, you will need to keep it watered as it will soon dry out. Submit your gardening questions to Diarmuid via his Instagram @diarmuidgavin using the hashtag #weekendgarden