主播大秀

Eric Robson chairs the horticultural panel programme from Cambridge. Chris Beardshaw, Bob Flowerdew and Christine Walkden take questions from the audience.

Produced by Darby Dorras
Assistant Producer: Hannah Newton

A Somethin' Else production for 主播大秀 Radio 4

This week's questions and answers:

Q. My Marjorie's Seedling Plum is normally prolific. This year, there was lots of fruit but it was tasteless. There was a large wound on the trunk, could this have anything to do with it?

A. The problem with a heavy crop is that the volume of fruit dilutes the sweetness. The tree may have contracted a bacterial disease through the wound - perhaps silver leaf is already affecting it. Next year, give it a big dose of manure and spray it with seaweed solution. Thinning may help. If it doesn't do any better, plant a 'Coe's Golden Drop' plum tree instead, it's even better!

Q. I have two Wisterias grown in the same place. One has thrived and one has not. What is going on? The Wisteria that is not doing well is a clear butter yellow, while the other looks healthy and is just beginning to get a bit of autumn colour.

A. This looks like a cultivation problem rather than a stock issue. This could mean the root is being compromised in some way; perhaps it has hit the foundations of the house? Minor changes in which the soil has been treated can affect the health of the plant. It's worth lifting the weak plant out and having a look at the soil profile and checking if there is any concrete or pipes down there (be careful not to rupture a gas or sewage pipe!) because this may be the source of the problem.

Q. How could I improve my Sweet Potato yield?

A. Don't grow them in the ground. Grow them in tubs or containers. Tie up the foliage into the sun; don't let it touch the ground.

Q. I planted crocuses under my apple tree beneath the turf. The crocuses grew up through the long grass. When I trimmed the grass with shears, there were bald patches. What should I have done differently?

A. Grass will get bald patches when it grows long, and Crocuses like free-draining conditions and lots of sunshine and so they will struggle in their current location. You could try growing Fritillaria Meleagris ('Snake's Head Fritillary') in the long grass instead. Try Camassias or just another variety of Crocus that thrives in damper, darker conditions like Colchicums ('Naked Ladies'). Mow the grass in the spring and summer and then let the grass grow for Autumn when the Colchicums will come through.

Q. The shoots and suckers of a Lilac grown in a hedge are taking over! What can I do?

A. This sounds like the Vulgaris species, it is very invasive and it will compromise other plants - so not a good choice for a hedge! Chris suggests letting one or two of the suckers to grow up to form a clear stem or multi stem plant that forms a canopy above the hedge rather than trying to incorporate it into the hedge. Bob disagrees, and thinks that Lilac can make a lovely hedge, just keep it under control with regular trimming.

Q. The plants in our small pond are getting overgrown, when is the best time to thin them out without disturbing the wildlife?

A. Bob says that there is no good time because the wildlife will be disturbed either way, but thinning in late November would minimise the disturbance. Take out as much water as possible before you thin and then pop it back in when you've finished because you don't want to put tap water in there.

Chris says that if you want to maximise the wildlife remaining in the pond after thinning, assemble a washing line above the pond and hang the removed plants on it so that any creepy-crawlies simply drip back into the pond. Leave the clearing to mid summer when the water is warmer and the larvae have moved on. You can clear the pond one section at a time.

Christine suggests you tell your neighbours what you're planning, because this can be dangerous. Eric suggests using a plastic hairbrush for removing the weeds.

Q. Could the panel suggest suitable rootstocks for apple trees that will be planted in less than ideal conditions?

A. Get a survey done of the site and then pay a visit to a rootstock expert like East Malling. Be warned that you won't be able to grow every apple variety well because some varieties need a very wet climate. Ensure that each plant has a custodian - someone to keep an eye on it and tend to its specific needs.

Q. What can I plant now that will look amazing within the next few weeks to wow a guest? I don't mind throwing money at it!

A. Autumn bulbs are the way to go. You can plant them in big swathes for a spectacular display.

Show less