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37 thoughts on “Forum

  1. My yew hedges have unsightly brown (dead) patches. They first appeared at the end of winter this year. Some bits started to rejuvenate but then collapsed. does any one know what is the cause? and more importantly what should I be doing about it?

    1. I was told that once you saw dead leaves it was too late to treat but saw no signs of infection earlier.

  2. I’ve been inspired both by Marion’s gravel garden and by Annie getting rid of all lawn, and am thinking of getting rid of our second (circular) lawn to replace it with gravel. Can anyone recommend books/articles on gravel gardening apart from the obvious one by Beth Chatto?……and what do the garden designers out there who know our garden think?

    1. Go for it Heather! I think it would look great gravelled and certainly would define the area.

    2. I don’t know of any books other than Beth Chatto’s. I think gravel would offset your planting style very well, and would add an extra dimension to your garden, too. I didn’t use any membrane under the gravel we laid as it can become disturbed when walked on, causing the edges to poke out in an unsightly way, and anyway I like self-seeders. Using different grades of stones provides context – larger ones can visually define the border edges – so choose a gravel which is available in different sizes so that there is continuity of tone and finish. We bought ours at Kingacre, next-door to Codicote Garden Centre, they have a good selection. Bulk bags are the cheapest method. About 3 – 4 25kg bags per sq metre will give good coverage. Plants that look good in gravel tend to be drought-tolerant sun-lovers, they tie in with the dry-garden look and tolerate the exposure well, too. Good luck.

    3. The Dry Garden by Mark Rumary is quite good. You can borrow my copy. I have never regretted getting rid of our front lawn. Most of the gravel we put down about 20 years ago has now worked its way into the ground. I, like Marion did not use a membrane to encourage self seeders. We haven’t ever added to the gravel as the plants have filled all the space!

    4. like Marion, I think it would define that section of your garden and look good, but I’m no garden designer. I eventually removed all the matting as it choked the developing plants, also the roots of unwanted seedlings got stuck in it and were harder to remove.

    5. What a shame i just found your question tonight. Spent all day teaching a one day gravel gardening course. Will be repeated again next year. Or just come on one of my open days and see my two gravel gardens. Derry Watkins, Special Plants

    1. Edwina, I cut down my newly planted achillea “Terracotta” after flowering as it was looking straggly so I’m hoping it will put on more growth.

    2. Yes, they should. I’ve got (early flowering) A. ‘Moonshine’ flowering again now, also an un-named pink one. I don’t remember getting (later) ‘Coronation Gold’, currently on its first flowering, to re-flower so maybe it depends whether they’re earlier or late season.

  3. Slug and snails. I managed to watch Gardener’s World last night and was surprised that Carol was recommending Sidalcea as a slug proof plant as I bought a S ‘Elsie Heugh’ years ago and it didn’t even survive long enough to be planted out so I’ve avoided them. Have other people been more successful? Slugs and snails and possibly the badgers on my Northampton allotment are currently enjoying pumpkins, beans (various) and onions. Unfortunately they are not eating the weeds!

    1. Are you sure it’s not mice? we caught 80 mice in three weeks who were peas, beans, clematis and goodness knows what else. Peanut butter is the bait to use.

  4. Liatris spicata – do any of you grow this plant? It is looking good in our garden at present, see: The purple spires are around 60 -75cms in height and have the curious habit of starting to flower from the top! They are in flower for around six weeks from mid summer and after that the brown stems maintain interest throughout autumn and winter. They look good in combination with grasses and other late flowering perennials. Bees and other flying insects love them. They are also extremely good value. I bought two packs of twelve large corms for £3.99 each at a garden centre last winter. Planted at around 20cms apart the two packs cover around a square meter patch of border, which is cheap! I recommend them. Adrian

    1. Apologies Adrian for a late reply but I agree, Liatris spicata are still looking good in the garden here but failed to reach the dizzy heights of your plants remaining at 50 to 60cms. It will be interesting to see how they survive the winter, mine are in a fairly dry position so should be ok and like you I found them very available and cheap to buy.

    1. I just took a look – it’s a rather unusual website in terms of navigation, try it from a desktop and you’ll see.

  5. Iris unguicularis are looking great now. However come June they look decidedly scruffy and floppy. I have had advice for and against cutting the leaves down in June and would be very grateful to know what you experts think?

    1. I’m absolutely no expert, Meta……but I tend to cut out just the very scruffy looking leaves, as I do with Libertias. I have a Geranium ‘Rozanne’ which flops over the top of my Iris unguicularis by June so the scruffiness is less obvious. I’ve never tried cutting all the leaves out. Perhaps try one section and see if it re-sprouts from the base?

  6. Thank you very much, Heather, for this sensible advice. I shall try the method of half and half by cutting down every other plant and leaving the others. We shall see….

    1. I’m dubious about cutting all the leaves off if the central fan is healthy. I think it may weaken the plant. It’s a bother to have to cut away only the outer leaves but I think it’s probably worth it to get flowers next winter. Sometimes, if the plant’s well-rooted, the leaves come away if pulled outwards, peeling off from the base, but I’ve been a bit cavalier in the past and ended up holding an uprooted plant, so maybe it’s better to resign yourself to a fiddly, knee-stiffening half hour. I like Heather’s suggestion of succession planting, with one plant hiding the tired remains of another.

  7. Does anyone have experience of Cornus capitata? I have a seed grown tree, several years old and about 7 feet tall which has never flowered. It seems to me that the recent cold winters, while not killing it, have knocked it back to such an extent that it has been unable to make flowering wood. Should I give it more time, speak to it severely or pull it out and see it as an opportunity to plant something else?

  8. A lovely deep pink Cheiranthus/Erysimum (biennial) has seeded itself in my garden & I’d like to propagate it. I’m rubbish with seeds, but prepared to try. Or could I take cuttings? If so, I’d be grateful for details.
    Many thanks,

  9. Hi Alison. If you wait until the flowers have finished, dead-head the plant and reduce stems by about half, then water it with a weak feed solution, you should find it produces new lateral or even basal shoots. Once they’re about 3″ long, you can take cuttings. Strike them in compost with 50% sharp grit and keep in a shady place. If you go via the seed route, it’s pot luck on the resulting colours.

  10. My turks cap lilies look very ‘odd’ this year. They grew as normal and the buds have developed into normal size blooms but all the leaves have died/dried off along the whole of the stems. This happened when the buds were still very small. As far as I can see there aren’t any blotches (fungus?) on the leaves or signs of insects.
    I will be so glad to know why this has happened and hope that the advice will not be to dig all the lilies up and not plant any more there for the next 5 years!

    1. Hi Meta, I’ve passed on your enquiry to the committee to see if anyone can help. Bill

  11. I have a Trachycarpus fortuneii which is about 10 feet tall (about 3 feet in 2002 when I was given it). If anyone is interested in having it you’d be very welcome – it’s too big for its space. As I don’t remember to check the Herts HPS forum very often, please use my email address – in case anyone is prepared to dig it up & cart it off!

  12. I suspect that this is somewhat off topic, but I will risk it anyway.

    I have been contacted by a committee member of the Welwyn Garden Society about the interesting idea for an Urban Arboretum within Welwyn Garden City. The project is currently being discussed amongst the “movers and shakers” of the town including the Society and the Borough Council. It involves the planting over time of interesting and unusual trees right across the town in suitable public green spaces, as well as in private gardens where visible to the public. It is hoped that this arboretum would become a significant attraction for the town with all the appropriate publicity and supporting leaflet material. The centenary in 2020, celebrating the foundation of Welwyn Garden City is also a consideration.

    I was asked whether I knew of anyone with a good knowledge and interest in trees, who might be prepared to become involved in the project, which is obviously at a very early stage at present. I couldn’t immediately think of anyone but agreed to ask around – hence this post.

    If you are interested or think you know of someone who might be interested, I do have some further information. So please feel free to email me

  13. I have several aquilegias which seem to be flagging. Att least half the plants seem to be growing normally, but the affected leaves start pale and distorted, then go dry & black & curling at the edges. No sign of snaill damage. Some new shoots near the flower buds have greenfly. There seems to be no sign of downy mildew anywhere, and there are no purple patches on the stems. It looks a bit like spray damage, and indeed 3 of the affected plants are near roses which I treated with Bayer Provado Ultimate Bug Killer 3-4 weeks ago. But there are also affected plants nowhere near roses.

    I don’t think I can send a photo, but I’d welcome any advice, particularly if it would be a good thing (alas) to bin the affected plants. Many thanks.

  14. It seems to me highly likely that this is indeed downy mildew which I understand is not visible in the same way as other mildews. There is a long article on the subject on the national collection holder’s website with lots of photos. (Just google aquilegia downy mildew.) I have been digging up affected plants right next to plants that still appear to be healthy.

  15. Has anyone used a Hotbox for composting? are they any good – reports vary but I have yet to speak to anyone who has actually used one. They seem expensive

    1. Hi Edwina, I will be interested to hear how you get on if you do try one, as I am giving a talk on composting to the HHPS in 2018. All my composting so far has been “cool”.

  16. Hello Everyone!
    we are looking for a couple of hardy plants and hoping that members will be able to point us in the right direction locally.

    1. philadelphus madrensis – it’s a very specific mock orange that we saw at Edinburgh Botanic Gardens. We actually smelt it long before we found it, and we’d love to have it in our garden.

    2. Hornwort Ceratophyllum demersum – this has been recommended to us as a British native pond oxygenator

    Many thanks in advance,


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