Q: Can I prune a Japanese maple and if so when ? MS via Facebook

A: Prune Japanese maples in the summer if you want to control vigour and you will shape the tree as you like more easily when it is in leaf. Don t prune maples too hard and avoid pruning in the spring.

Q: I thought all dahlias came back every year; why don't mine? TC via Facebook

A: Dahlias survive the winter underground in the form of a tuber. Traditionalists lift the tubers at the end of the autumn for storage and plant them out next spring. Dahlias will fail if left in the ground if we have a cold or wet winter as they will get frosted or rot. Slugs can also eat the shoots before they emerge above ground. If you want to try again and leave them in the ground for winter you must have free draining soil. At the end of the autumn cut the plants back and put a good layer of straw or hessian over the plant. Prop a roof tile over the top to keep the worst of the rain off. Clear away in spring and keep slugs at bay.

Q: What is the fastest growing tree for my garden? DG via Facebook

A: Gum trees (eucalyptus) are very vigorous and evergreen as is the cherry laurel. Poplars and sycamore are quick but they are huge plants when mature.

Q: Should I rip up my kiwi plant that hadn't flowered in 10 yrs? I only have one. KS via Facebook

A: You need male and female kiwi for pollination to produce fruit. It's difficult to tell them apart, maybe you have a male plant. After 10 years of no show I would call it a day.

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