Brian answers readers’ horticultural queries
I grow peas on my allotment but find those I sow in June are spoiled by a white covering on the leaves and often this disease infects the peas in the pods. There must be a way to prevent this. Do you have an answer? JR, Copnor.
This is pea mildew. It can be prevented by spraying once a week from mid-June. Use Bordeaux mixture dissolved in water. It is often serious if the roots get too dry. Regular watering reduces the risk. If you think the spraying programme is too much of a chore, spray the plants as soon as you see the first signs of the mildew and then once a week.
Can you tell me what is attacking the bases of the stems on my lobelia cardinalis (pictured)? They have distinctly linear, quite deep, gouges. RB, Portchester.
Thank you for bringing in the sample in dry newspaper. It arrived in perfect condition. This damage is caused by tiny black or brown slugs at night; they are about the size of a match head. Soak the roots with Slugclear liquid slug killer.
Is it too late to plant runner beans? I was given a copy of your brilliant method of growing them in a growing bag. I live in a flat and would like to have a go. Is it essential to use 8ft canes? HF, Shinfield, Reading.
I used to live at Shinfield when I was a boy. It isn’t too late. You may still find plants at your garden centre and 8ft canes are essential. Get someone to help you pick them.
JOBS FOR THE WEEK
Did you remember to cut back aubrietia plants? There is still time to do this. Give them a liquid feed afterwards.
Spray rows of peas with Fungus Fighter fungicide to reduce powdery mildew – one of the reasons why people don’t grow their own peas.
Indoor hibiscus plants are growing rapidly. To keep them shorter, nip out the tips of all the main stems.
Remove dead flowers from all annual flowers and when the weather is hot, use a high nitrogen fertiliser instead of tomato feed.
Buy a packet of spring cabbage seeds. Try Duncan F1 or Offenheim 2. These don’t bolt if the weather suddenly turns hot in spring. These must not be sown until the second week in August. I will remind you.
Disbud dahlias. Leave the top bud and remove the two flower buds which grow each side. When cutting dahlia blooms, long stems are needed, but before cutting look where the side shoots are left because these will come into bloom in a few weeks.