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Ness Botanic Gardens - Correspondence Edition

Horticultural panel programme. Eric Robson and the panel present a correspondence edition from Ness Botanic Gardens.

Eric Robson hosts a correspondence edition of the programme from Ness Botanic Gardens. Christine Walkden, Bob Flowerdew and Pippa Greenwood are this week's panellists, answering questions sent in by letter, email and social media.

The questions include ways to rescue dying plants, using coffee grounds as compost and how to win a sunflower growing competition.

Also, Peter Gibbs meets with Charlotte Smith from Â鶹Éç Radio 4's Farming Today to discuss Glyphosate's future in our gardens.

Produced by Dan Cocker
Assistant producer: Hannah Newton

A Somethin' Else production for Â鶹Éç Radio 4.

Available now

43 minutes

Last on

Sun 22 May 2016 14:00

Fact Sheet

Q – I have planted up the tree-pit in the street outside, a small 40cm x 40cm (16 inches x 16 inches) plot, with a small Field Maple planted in the middle. It has free-draining soil and we have put 10cm (4 inches) of moisture retaining compost on top. Dog urine seems to be killing off most things - can you recommend urine-resistant plants? Ìý

Christine - Denticulata auricular seems to be alright – it’s very much species related so I would use trial and error. The real issue could be the dryness of the soil – add much more organic matter into the pit.

Bob – Once daily rinse down the plants with a watering can – in the soil it will be a nutrient but it’s a problem on the leaves.

Pippa – Lamium album or ‘dead nettle’ are meant to be resistant. Ìý

Ìý

Q – What are ladybirds eating in May? Is there anything I can do to encourage them to stay on my allotment?

Pippa – There are plenty of green and black fly about by May so they should be ok.

Bob – Most of the ladybirds that are over-wintering are positioned on tufts of grass with stinging nettles – when the nettles are 6-12 inches (15-30cm) tall – that is when the aphids appear.

Ìý

Q – We have Mistletoe growing on an Egremont Russett (Apple tree) – is it possible to identify from the leaves if this is a male or female plant? If we do get berries that the birds can eat, can we expect to get more growing on neighbouring trees?

Bob – I don’t think you can tell from the leaves – there are many varieties and sub-species – but if it’s growing on an apple tree then it could spread to other apple trees.

Pippa – The best way to grow it is to use the fully-ripened berries from the mistletoe on your apple tree and wedge them into cracks on the other trees.

Christine – They will normally ripen around March or April – it will lose its shiny appearance and go dull and slightly pearly and that’s the time to stick it in the bark. Birds can clean their beaks on to the trunk and that is how the berries get wedged in.

Ìý

Q – On the other side of my garden fence there is a retaining wall with a drop of 3m (10ft) to the lane below. The concrete wall is an eyesore from the other side – what do the panel suggest that I plant in my garden that will trail and cascade over the wall?

Bob – Ivy is tempting but in a wet climate it could take over the rest of the garden – Clematis montana might work well – I like the ‘Wilsonii’ variety which has a chocolate smell.

Pippa – I would suggest Clematis montana ‘Elizabeth’ – which has a lovely perfume. If you wanted something that was more foliage orientated, try Parthenocissus henryana (A variety of Chinese Virginia Creeper) which is less inclined to be too vigorous.

Ìý

Q – Rats have taken residence in my raised beds – I was hoping to plant vegetables this spring but I’m worried the soil will be contaminated – how long will it take for the soil to be safe to plant in again? Is there anything I can do to decontaminate the soil?

Bob – Blood, fish and bone meal in the compost might attract the rats. The organisms in the soil should decompose the diseased organisms from the rats’ urine – but it’s where the rats run on dry sections that they can disperse Weil’s disease from urine on their feet.

Pippa – They could be coming through draining holes through the base. I wouldn’t worry too much – water it more than you might have done and put a mulch of new material on the surface to stop splash up onto the leaves of salad crops.

Ìý

Q – Are you meant to oil your tools after using them? And what oil should I use?

Bob – It is necessary because wood dries out and can splinter – if it’s oiled then it’s more waterproof and lasts longer. Oil also prevents rusting on clean metal. Don’t use old engine oil as it is really toxic. I use old frying oil – it’s a recycled waste product.

Pippa – Inexpensive Rapeseed oil or Vegetable oil will do the trick and is not scented.Ìý

Ìý

Q – I have an 11-year-old Geranium which is still flowering but has become quite gangly – I have kept it indoors (east-facing window) – How can I control the spread and make it fuller without killing it?

Christine – Just prune it – reduce the plant by half which will create growth from the base of the plant and should thicken it. The PelargoniumÌýgeranium should enjoy the dry conditions and can live for years.

Ìý

Q – My friend and I like to rescue dying plants from clearance benches at garden centres, do the panel have any plants they have rescued? And do they have any tips for reviving a plant on the brink of death?

Bob – Usually they have dried out – so I recommend gentle watering – stand the plants in their pots in a large bowl of warm water with just a little soap, leave it in there for 30-60 minutes then take it out and drain it. The plant will dry out the compost and then you have to start watering – don’t feed it straight away, only once it starts moving.

Pippa – If you are talking bedding plants – deadhead them, water them, give them a bit of feed and many more flowers should appear.

Christine – If something is very root-bound (very woody roots coming through the bottom of the pot) they are very difficult to rejuvenate – but if the top growth is looking sad or it has gone over then those are easier to help. Be selective when rescuing.


Q – I am currently fighting Himalayan Balsam (Impatiens glandulifera) and losing – it is taking over large parts of the garden. I would like to fight back by planting some trees with deep root systems – what can the panel suggest? The bank is sloped, sheltered from the wind and in a sunny position but I live in the Ribble Valley so the trees need to be hardy and enjoy plenty of rain.

Christine – You need to get plant material in such as Dogwoods, Willows, Alders and if you coppice them down every year the roots will run well and sucker and bind the soil together. Event plants like the Wild Iris (Iris pseudacorus) and Hemerocallis (Daylilies) will also bind it. It is relatively simple to pull out the Himalayan Balsam.

Bob – On the bank I would use brambles because they will bind the soil, arch over and create shade and should exclude the Himalayan Balsam.

Christine – Hand pulling does work but when it is done to natural areas it can cause horrendous damage to flora and fauna. You may have a problem with seeds being washed down and re-arriving.

Ìý

Q – This year my family and I are having a tallest-sunflower competition, we are all growing the same variety called ‘Earthwalker’ which is a hardy annual – could you give me a few tips for how to get the best results?

Christine – plenty of feeding and allow the plant to get to 6-9 inches (15-23cm), then use plenty of good quality compost and feed and water like mad.

Pippa – Definitely protect it against slugs and snails because particularly when they’re small, they can be lost overnight. If the area is windswept, give them a little bit of support to stop it falling over.

Bob – Don’t put any other plants near it, give it 90cm x 90cm (35 x 35 inches) to itself.

Ìý

Q – My local supermarket is giving away used coffee grounds for customers to use in the garden – Do these grounds contain enough Potassium to promote flower and fruit growth? And are they good enough for feeding tomatoes and pots?

Pippa – Any organic matter could add something in the way of food materials but it smells when it gets warm in the sun and you would be better off starting your own compost bin.

Bob – I would compost them first and because they are dark they will make the compost darker – if you make a darker compost it absorbs more of the warmth and therefore the roots and the soil are warmer. You could spread the coffee grounds around Asparagus plants because the warmer the soil, the earlier the crop.

Ìý

Q – We rescued an avocado seedling from our compost heap and potted it in our conservatory – it’s now over 6ft (1.8m) tall, 4ft (1.2m) wide and has over 5 branches. What do we do now?

Bob – I’d try winding them round in a circle because they are flexible and that turns it into a lower tree. It’s seldom going to crop – I would put it in the garden and if it doesn’t survive it’s no great loss.

Christine – It can be an enormous tree – up to 50ft (15.2m) high and 30ft (9.1m) wide.

Ìý

Q – My mother, once or twice a year, digs up her slate shingle path around her garden and empty it into buckets. She then proceeds to wash each load thoroughly and leave it in trays to dry in the utility room before returning it to the path – Is this necessary to keep slate clean and free from weeds and bugs?

Christine – No, categorically no.

Pippa – There is no need. Perhaps make some planting pits in the slate and get plants growing in there.Ìý

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