Brian answers readers’ queries
What’s gone wrong with my roses? The leaves on some plants are normal but others are distorted. WGP, Fareham.
Your specimen arrived in dry paper, thank you. Someone near you is spraying to kill weeds with a hormone weedkiller. Take off all infected leaves and feed with Maxicrop for tomatoes. With a bit of luck they’ll survive. Let me know how things turn out.
You identified a shrub for me in 2008 – clerodendron pleniflora (pictured). I pruned it by a third but it’s still too tall. How can I reduce it? ML, Waterlooville.
Prune very hard when flowers fade and use a spade around the shrub’s canopy. Thrust it 12in down to sever lots of roots. Scatter half an ounce of sulphate of potash per square yard over the area inside the canopy to ensure flowers next year.
Can you identify the weed in my brother’s garden. How do we get rid of it? WB, Hilsea.
It’s horsetail, the most difficult weed to control. With much patience, use Roundup mixed with cooking oil. Cover every shoot and it will do the trick. Ensure it’s not coming from next door. If it is, ask the owners to do the same.
I have transformed my borders by planting cosmos for the first time. I bought them in pots and the large daisy-like flowers look marvellous. LF, Horndean
I’m glad you read my article about cosmea. They are a delight and will flower all summer if dead-headed regularly.
JOBS FOR THE WEEK
Take 3in cuttings from aubrietia plants and remove the bottom 2in of leaves. Put them in a 50/50 mix of sharp sand and seed compost. Put them in the shade and protect from cats. They should root in four weeks.
Place greenhouse ferns in a shady part of the greenhouse. They’ll get scorched leaves if left in direct sun.
Feed greenhouse cucumbers by top dressing the compost’s surface with a little Vitax Q4 fertiliser. Water with a rose on the can. In a few days new white roots will appear on the surface. Now top dress the compost with John Innes No3. This increases the number of fruits. Repeat several times at weekly intervals.
Summer prune apple trees by reducing side shoots by half. The prunings will be soft and should be composted. This will induce fruit buds for next year’s apples.
Use fingers and thumbs to see if early potatoes are ready, don’t dig the whole plant. Give it a liquid feed to encourage more tubers. Spray the foliage with Bordeaux Mixture to prevent potato blight.
Thin grapes again and blow sulphur dust onto the bunches to prevent powdery mildew.
Check tall flowers in borders. They may need staking.