Q&A with Glenys Woollard - Gardening
Our 7-year-old oak tree (Quercus robur) is growing well, so why hasn't it produced a single acorn?
Be patient. Most oaks need to be at least 20 years old before bearing acorns, with some taking as long as 50 years. But once they start, you should get bumper crops for many decades.
The acorns develop from flower-like structures that look like catkins and appear around the same time as leaves in early spring.
An oak can grow to 35m high with a spread of 15m.
What can we do about the lower leaves of our broccoli plants developing greyish spots, yellowing, then falling off?
Sounds like ring spot, a fungus that affects brassica plants. Check with a garden centre for suitable fungicides if you want to spray, but note that control is best achieved earlier. Ring spot overwinters in fallen leaves and on some weeds, producing spores in spring.
Keeping your patch clear of rubbish and rotating crops is the best way to avoid problems in the future.
If you have a gardening question, email Glenys at glenyswoollard@clear.net.nz
