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Birmingham Botanical Gardens: Correspondence Edition

Peter Gibbs hosts a special correspondence edition from Birmingham Botanics. Neil Porteus, James Wong and Bunny Guinness answer questions from the postbag..

Produced by Dan Cocker
Assistant Producer: Laurence Bassett

A Somethin' Else production for Â鶹ԼÅÄ Radio 4

Available now

42 minutes

Last on

Sun 7 Oct 2018 14:00

Fact Sheet


Q1 – My cordyline is getting ever more straggly and unattractive looking. It is 4 metres (13 foot) tall. Should I prune it back hard and when should I do that?

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Neil – It can be rejuvenated. Find the sunny side of the Cordyline and about 18 inches (1.5 feet) away from the main trunk get a spade and cut round half of the bowl. Leave it until next spring where you will get little initials coming from the south side of the cordyline then you have options to reduce it. It could also be getting starved, as they love moisture.

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James – The most important thing to remember is where they come from. They require lots and lots of water and mild conditions. Add water and fertilizer. Enrich the soil, so it can contain more water.

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Q2 – My azalea first bloom was fine, but in second bloom the buds and blooms are curled with brown edges. It has been in our conservatory and has been watered regularly. What can I do?

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Wayne – It could be that the humidity levels are very low.

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Bunny – Move its position in the conservatory, get it under the shelter under another tall plant to give it not so much sunlight.

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Neil - Prune it back a little bit – if it is evergreen you can prune it back 3 inches (7.5cm). ÌýLook at the roots and see if you can shift it up a size. Give it a little more space to grow in to. They respond well to pruning.

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Q3 – I have a number of different types of half-hardy salvias which have been spectacular this year. How should I protect them over the winter?

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Wayne – You can dig the main plants up and pot them up in a well-drained compost. Somewhere fairly cool and frost free.

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Bunny – Leave them out and take cuttings.

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Neil – You need about 3-4 inches (7.5-10cm) semi-ripe cuttings, you need to flex the non-flowering stems if possible from the side shoots and the back of the plant. If they are quite stiff to the touch that is good. Cut immediately under a node with a sharp knife to cut out the leaf petiole and the bud and put them even in pure sand they would be fine and they would root in about a month.

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James – If you don’t want to move them you can cut them in half and cover them with enviromesh.

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Q4 – I recently moved into a flat without a garden and I decided to try my hand with indoor plants. None of the pots seem to have drainage holes. Is it ok to plant something in a container without a hole – would I be able to get away with little and often watering without the holes?

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James – None of mine have holes in them. If you did find one with holes you may ruin the flooring or furniture. Without the drainage holes you need to water less.

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Bunny – I got a little metal tray to cover my windowsill an inch deep and put my pots in that

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Neil – Aquatic plants – you can never overwater.

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Q5 – I have a south-facing dry garden, how can I grow chia seeds and where can I get them from?

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James – They are one of the easiest plants in the world to grow.Ìý It germinates incredibly quickly and easily. You can get the seed from the supermarket.

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Q6 – We dug some compost from our compost bin into our front garden where the soil quality was very poor. We found two melons growing, they look like cantaloupes, will they ripen and can we do anything to help them ripen?

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Bunny – Get some seeds and try them next year. Unless we have an amazing summer that goes on until November.

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Wayne – They are a glasshouse crop.

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Neil – If it is getting frosty you could bring them inside, put them on a sunny windowsill next to some bananas to get some ethylene, and you might be able to get something.

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Q7 – I have been attempting to grow my own turnips for the past few months but have been struggling with clubroot. I have added plenty of lime but to no avail – what should I do?

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Neil – You need some fresh soil and to box it up to take it out of the splash-zone and grow it somewhere else. Grow it in a big container and try a few turnips.

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Bunny – Get a big raised bed. You can even so them inside now and you might get some young turnips. Sow them n a raised bed, full of compost.

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Q8 – What should I do with my flourishing young apple tree in winter? It is about 3 inches (7.5cm) high. It is outside in a flower pot.

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Wayne – It will be hardy. By autumn it needs to be in the ground

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NeilÌý - I would put a cane in so no one steps on it.

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Bunny – Watch for rabbits. It could grow up to 8 metres (26 foot) plus so plant it where it can grow up to that size.

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Q9 – I have bad sinuses and difficulties with smells. I love the smell of lime tree flowers but I am unsuccessful in finding a suitable variety.

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Neil – Petiolaris Ìý(weeping silver lime)– is one of the best for flowering and scent.

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Q10 – I live in open-countryside with a nice sunny aspect, I have been inundated with shield beetles on my dahlias. Are they a pest and should I get rid of them?

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Bunny – I would leave them

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James – They don’t do any damage.

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Q11 – Bracken is harvested every year in the New Forest. It is sold as a peat substitute – would the panel recommend using bracken?

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Wayne – It is quite acidic so you need to be careful where you use it

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Bunny –I would definitely use it.Ìý

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James – Mix it with leaf mold and it is perfect for ericaceous plants. It can help keep plants warm in the winter.

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Q12 – I had my cat cremated I would like to use the ashes with some planting in his favourite place. I would like to grow a range of plants – any recommendations for year round interest?

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Neil - Magnolia ‘star-wars’

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Wayne – Catmint

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Bunny – Summer Magic (Nepeta Grandiflora) is an amazing catmint

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James – Silver vine (Actinidia polygamaI) has scented flowers and edible fruits. And it produces chemicals, which produces pheromones in cats.

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