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Sample Questions and Answers

I have bought a lovely deep pinkish red, small flowered cyclamen and wondered if it was hardy?
It has no variety name on it.

It's hard to be certain about the hardiness of this Cyclamen. If it was being sold as what might be called a 'winter bedding plant', then it will depend very much on the kind of weather we get this autumn/winter and where you live. If you are in the south, and have a sheltered spot to put it in, it might well survive for several months outside. But a real, hard, frost will finish it off, even if it is advertised as 'winter hardy'.

I suspect that this is what you have bought, especially if the plant has well-developed foliage as well as lots of flowers.

It just might be a form of the species Cyclamen hederifolium, which is hardy and can be planted outside. However, its habit of growth is to produce flowers in the autumn and develop foliage after the flowers have more or less finished. It is also smaller in all its parts than the kind of 'bedding' cyclamen which are in the shops and garden centres now.

I live in Cumbria with an acid soil and grow excellent hydrangeas but these are all blue. I have a 'red' bed and would like to grow a red hydrangea in it and in a semi shaded position. Preferably a mop head, medium growth ie 1.5m max height and spread and one that will retain its colour and whose leaves change reddish in autumn. What can you recommend? I'm quite happy to 'mulch' with chalk each spring.

According to the RHS, Hydrangea 'Preziosa' as one that retains its rose-pink, ageing to crimson-red flowerheads 'even on acid soils'. This is a compact variety (1 -1.5m) with purple tinged young stems and globular flower heads.

Will the shoots with green leaves of Elaeagnus pungens maculata become variegated next spring/summer or should they be removed? I can find no guidance on pruning. Please help.

Any green shoots on your Eleagnus pungens maculata should be removed: unfortunately the production of green shoots is a characteristic of this handsome shrub.

As far as pruning goes, this is a very forgiving subject, which is why it is quite often seen in public landscaping schemes, where it can even be kept clipped to quite formal shapes. Since the very fragrant flowers are produced in autumn, it is probably best to prune in the spring, shaping it up to your own requirements. It will even respond good-temperedly to cutting hard back into mature wood, so you don't need to feel at all nervous about having a go at it!

I grubbed up a lovely little grove of bamboo in a shady nook behind the house which had become rather invasive and so it had to go.

I am now desperate to find something that will help cover up some ugly pipes in the nook. No direct sun ever falls on this back wall where the pipes are. It faces northeast, but the morning sun is blocked by the way the house juts out. The amount of indirect light is good, I suppose -- a rhododendron in a large pot back there flowers reliably. But I am keen to have a climber to cover up those wretched pipes. The soil is loamy, moist, fairly well-draining. It is also somewhat alkaline, though has been much amended with commercial bags of neutral top soil and manure.

Would a Clematis montana flower in a shady situation, do you think? And what about a Pyracantha? Do you think it would it produce berries? Any advice and suggestions of other attractive climbers would be most welcome!

As far as finding something suitable to cover up the exposed pipes, the situation is not too bleak. Of your suggestions, the Pyracantha is certainly tolerant of your conditions and could be trained against the wall to give flowers and wonderfully coloured fruit. They are susceptible to both canker and fireblight, but the varieties 'Sappho Orange' 'Sappho Red' and 'Sappho Yellow' are said to be resistant to these diseases. Clematis montana would not be at all worried by shade at its base, but would then shoot up to find light in order to flower, so may not be suitable. 

There are other climbers that will manage with the lack of sunlight: Parthenocissus henryana (one of the 'virginia creepers') has beautifully marked leaves which colour in autumn and is self clinging. Unfortunately it is deciduous, so only the framework of its stems would be there in winter. Although technically a shrub, and also deciduous, is Jasminum nudiflorum, but its early flowers give it interest in winter until the new leaves grow. Prune after flowering to maintain a fan-shape against the wall. Also deciduous is the rather interesting Muehlenbeckia complexa grown primarily for its curtain-like habit and tiny interestingly shaped leaves. It bears tiny green flowers in late summer: it might sit rather nicely in the Japanese style. Ivies of varies types would of course do a handsome year-round job, but without flowers. However, choosing a cream-variegated one would bring some light into that area, as would the evergreen Euonymus fortunei 'Silver Queen' which will reach 2 to 3 metres when grown against a wall.

Finally Camellias could look good here, as long as the situation is sheltered from cold winds and comfortably warm in summer. Since you already grow a Rhododendron in a container, you are obviously familiar with the sort of soil needed and the watering regime in summer, so it is just a question of whether you would be prepared to add more containers.

I am presently involved with trying to grow a Tudor garden at a 17th century hall. 

So far there are two kitchen garden beds approx 12ft x 12ft, which has some basics in them, chives, rosemary, pennyroyale, mint. Also dotted about the beds are examples of blackcurrant, gooseberry and lavender and in the middle of one bed there is a Medlar Tree. There are six raised beds 4ft x 4ft which I want to use to illustrate herbal uses during the 16th and 17th century.

As far as planting out the six 4 x 4 ft beds, one way of designing them would be to put a tall plant in the centre of each bed, with lower growing ones planted round them. This would work from the point of people viewing them from all sides. If they are to be viewed from one side only, then put a couple of taller plants along the back of each square, with lower ones in front. Many herbs are vigorous, so don't plant each bed too full or some will get squeezed out.

You don't say what the aspect is, but there are herbs for both sunny and shady situations: a visit to a specialist herb nursery will make sure that you get the right herb for the right place. As we don't know from your query what part of the country you are in, search on the web for 'herb nurseries' and see which are nearest to you.

If the garden you are working on is open to the public, you will need to take care from the point of view of poisonous plants and so on. One that needs to be mentioned in particular is Rue, which would almost certainly have featured in a 16th/17th century herb garden. If skin is brushed against rue leaves, and then exposed to sun, severe photosensitivity blisters can result for susceptible people. So do your research carefully with as many good reference books and advice from herb growers as you can manage.

I am wondering if you could give me some advice about my Sea Holly please? Its an established plant in my border and has been in place for about three years. It flowered the first year but not since, but it does have a lot of leaf growth and looks otherwise healthy. Its at the front of a border but is not in full sun the whole day as the border is partially shaded by a fence late in the day.
I am wondering whether to try and move it to an area with more sun?

It is rather difficult to give precise advice without knowing which of the many Sea Hollies you have in your garden. The behaviour of your plant may suggest that it is a form of Eryngium giganteum, sometimes known as Miss Willmot's Ghost Sea Holly. This is, in theory, a biennial but it often takes more than two years to start to flower. However, the fact that it has flowered before may rule this out, unless the one you have now is in fact a 'child' of the first one.

The lack of sun for part of the day should not be too much of a problem, especially as the plant is looking healthy.

Since Sea Hollies do not like disturbance, it is probably best to leave it where it is to give it a chance to flower next year. To encourage flowering of this, or any plant, a feed rich in potassium (potash) will help. In a general fertiliser which lists N (nitrogen), P (phosphorus) and K (potassium), look for one that has a high percentage of K. (Tomato fertiliser may be suitable).

As usual I have been overwhelmed by my seed raised plants and now have a greenhouse full of plants dying to go in the ground but I would hate them to be killed over winter after all of my tlc.

The plants I'm particularly talking about are Ammi and white snapdragon.I know that we are advised that both of these make bigger plants from an autumn sowing but these are biggish plants already-will they survive outside?Or should I continue nurturing them in the greenhouse/cold frame?

I've also got lots of agastache in plugs-if I plant these out in the next few weeks will they be okay?

Sounds as if you have had a succesful year with your seeds!

Starting with the easy answer - it would be best to keep Agastache until the spring before planting out. It is always difficult to be certain about hardiness, but some are borderline in cold gardens, and certainy more vulnerable when young.

As far as the Ammi is concerned, it is more difficult. Autumn direct-sown Ammi tends to germinate in the spring, and then grows rapidly. So the seed is what is sometimes called 'winter hardy'. However, plants themselves being 'soft' may not be quite so hardy if we get a hard winter. There is the additional problem that they do not transplant very well, hating disturbance to their taproots. This would suggest planting out now before they get too settled in their pots. A bit of a dilemma! A belt and braces approach may be best - plant some outside now, and pot on the remainder into as deep pots as possible ready to plant out in the spring. Snapdragon is tougher and easier to transplant, again with the proviso that we don't get a really hard winter so a half and half approach may also be a good idea with them.

Please could you tell me something about Clematis crispa which I am unable to find in any of my reference books.

I received seed of this variety from the HPS last January and one seed has germinated and grown into a healthy looking plant. At present it is 6 inches tall and is in a three and a half inch pot with a small cane for support, but there is no sign of any tendrils which makes me wonder is it an herbaceous variety rather than a climber?

Any information and advice you can give me about this clematis would be much appreciated.

Clematis crispa comes from southern USA, and has several 'common names' among which is Marsh Clematis. So this will tell you that it likes a warm spot and soil that is consistently on the damp side. When you plant it out in its final position, plant it quite deep.

It is a climber, reaching six to ten feet and flowers late in the season with very pretty small blue bell-shaped flowers. Prune hard in spring, taking all growths down to about nine inches/20 cms.

I have planted a Solanum crispum in a large tub but it doesn't seem to be doing very well. Was it the wrong thing to do? It is in a paved area where we have put up trellising. A trachelospermum seems to be ok in a pot in a similar position.

Solanum crispum is not usually too fussy about soil, only needing a sheltered position to give of its best. However, it is normally very vigorous and really might find being restricted to a container, however big, not to its liking. It's not clear from your enquiry if your plant was doing well but is now unhappy, or if it has never really got going. If it has been good and is now struggling, it could be that it has run out of reserves in the tub, and its roots really need more room and more nutrients.

If it has never really been happy, this could be down to several causes of which drought or drowning are two! As we don't know what sort of soil it is in, and how well it drains, this could be the problem. A three to one mix of John Innes No 3 and general purpose compost should be about right, as this will give it some stability while also allowing the medium to be free draining and 'open' enough. Obviously, with regular watering, you will need to replace the washed out nutrients on a regular basis during the growing season. 

The other possible cause of its unhappiness is that its roots might be getting too hot. Many climbers really need a cool root run, even if they prefer their top growth to be in a sunny sheltered spot. Clematis and some Honeysuckle, for example, would fall into this category.

We've got two large natural ponds, dug about 4 years ago-one is full all year round but the other one gets steadily emptier as the summer goes on. They are in a field so so we suspect that one has old land drains underneath. This looks very unsightly,just a big muddy hole, so I was wondering if there exists a plant that would cope with being under water all winter and dryish all summer.It doesn't have to be spectacular-just something that would cover the clay.

You don't say how deep the water is during the winter, and this is really quite critical in determining which plants will tolerate a varying depth of water. Many of the plants described as 'marginal' tolerate conditions from damp mud to water standing up to about 6 inches deep, so there is plenty to choose from there as long as the winter water is not too deep. Fewer plants tolerate a range from 'damp' to anything deeper than 6 inches.

There is also the problem that many of the plants that would cope with a dry period followed by deep water are so vigorous that they would choke the pond: reeds and rushes for example. It would probably be worth visiting a specialist nursery or supplier, once you know the usual depth of the water in winter, and being advised by them.

I've got lovely shrub roses in the front garden which are getting very tall and I would like them trained up the house walls.My husband is unwilling to use screw and wires because our house is made of attractive old stone and he thinks the fixings would look unsightly,especially in the winter when the roses are bare.Is there any way of fixing them discreetly?

With all due respect to your husband's reservations, the use of wire and vine eye screws is the most unobtrusive yet robust way of supporting climbing roses. Galvanised wire (rather than green plastic covered wire) weathers quickly, and the vine eyes would also quickly weather and become almost invisible against stonework. It is hard to come up with anything that is more 'discreet' but strong enough to support the summer weight of healthy, flowering, climbing roses. It could also be argued that well-pruned and fan-trained bare rose branches can look very attractive and sculptural in the winter!

The alternative would be to deliberately choose something noticeable, like attractive trellis panels. These could be painted in one of the subtle shades now available for outside wood work; there is probably one that more or less matches the colour of the stone. The panels should be mounted on spacer blocks so that there is a gap between the panels and the walls to allow the rose growths to go behind the wood lathes and weave themselves more securely into the trellis.

I hope that you can help me with a problem I have experienced with a Hamamelis plant that I have had for about 5 years or so. It has always been very healthy, has grown well and flowers profusely. It is in light shade in loamy soil and is watered when I feel it necessary. All of a sudden, all the leaves have turned brown and crinkly and the forming flower buds are no longer in evidence. This has occurred in the space of 3-4 weeks. At first I thought that it was experiencing an ‘early autumn’ but I think that it’s chances of survival are pretty slim. One of our local HPS group members looked at it and suspects that a neighbours walnut tree is the problem because, apparently, they produce a substance which is toxic to other plants. The tree is about 5-6 years old and is growing at quite a rate and is partly shading the hamamelis. Do you think that it is the culprit or can you offer another reason please.

There is considerable evidence to suggest that the Black Walnut is particularly toxic to some nearby plants, and some authorities say that the Common Walnut also has a detrimental effect.

The roots of walnut trees, which can spread far further than the spread of the branches, exude a toxic substance which is harmful to quite a list of trees, shrubs and plants: unfortunately Hamamelis is one of these. Apparently the drip from the leaves can also be harmful. So taking all things into account, it does sound as if this might be the problem. Even if you were able to persuade you neighbour to remove the walnut, the problem would still persist as long as the root system remained in the ground.

The suddenness of the Hamamelis' demise almost certainly points to some problem below ground, so unless there has been a drastic alteration in ground conditions (unprecedented drought or drowning) then it looks as if the walnut might be the culprit. There is the remote possibility of honey fungus being responsible: is there any evidence of this being present in your, or your neighbour's, garden? Not that this would be a comforting diagnosis either!

I purchased a ‘Mock Orange’ last year from a garden centre. No blossom or flowers. I can’t recall pruning since its purchase. This year the plant has sent out many tall (4-5 foot) new growths but no sign of any flower buds or blossom. The growths continue to get taller!!

It is now the end of June. Should I prune this plant hard back now and wait until next spring to see some development.

This must be very disappointing for you, especially as Philadelphus everywhere seem to have been laden with blossom this year.

But there is probably no need to worry; just be patient! The new growths you describe will be next year's flower-bearing branches. So, you might just 'tip them back' (i.e. cut off perhaps 30 cms at the end of the growths) but don't prune any harder than this. You can also cut out the older wood (which is what was probably there when you bought the plant). This will give you a shrub that is made up entirely of next year's flowering branches.

Each subsequent year, after flowering cut out some of the wood that has borne flowers, leaving new replacement wood alone (unless there is too much, in which case you can take out weaker growths.)

Hope this reassures you and that you have plenty of blossom next year.

Which stems on Winter Jasmine should I prune out when it has stopped flowering. Some branches look old and woody. How far down to the roots should I prune?

You are right to be thinking of pruning your winter jasmine after flowering and to be concentrating on the old woody branches as these will in time create a tangle of dead wood, depriving newer growths of light and killing them. So, cut out as many of the old growths as you can right back,even to the ground, or to where younger growths can be seen. It is after flowering that new growths should be appearing, both from the base and from older branches.

If there is little sign of new green growths, restrict the removal of old branches to about half the total, and remove the remainder the following year. Feed and water the plant to encourage new replacement growths: winter jasmine is often grown in situations where there is rain shadow, so some watering and feeding in the summer is appreciated.

In general, try to train the plant into a fan shape, tying it into wires or something similar as this will make sure that all the branches get light and air. Keep the leading growths, but cut back laterals (side shoots) quite hard, to keep a clear fan shape. These will ripen over the summer and bear flowers next winter.

My Choisya plant is getting a lot of dark green leaves and although I use the secateurs to cut them off just above the soil they still turn a dark green when they grow again. Do you have any advice for me so that they grow with golden/yellow colour leaves?

Unfortunately the golden-leaved forms of Choisya are prone to reverting to green. You are doing all that can be done (i.e. cutting out green shoots whenever they appear) and it is most important to do this as the more vigorous green shoots would in time overwhelm the less vigorous golden ones. Sorry that there is no magic solution to the problem!

I wonder if you could help me with advice on a Forsythia Spectabilis that I have just bought. I planted it a couple of months ago but now the leaves are turning brown and falling off. Could you tell me what I am doing wrong?

This is very odd because generally speaking Forsythia are more or less bomb-proof. If the leaves are browning and falling off it would suggest that all is not well below ground with the roots. It could be that it is too wet, or too dry!

Did you soak the root ball and the planting hole as you planted it? If not, it could be that it is dying of drought in which case generous watering might give it a new lease of life. Newly planted shrubs, especially if in full leaf, are very vulnerable to drying out and need watering during dry spells for some weeks after planting.

On the other hand, if you have had a lot of rain in your area, it is just possible that you planted the shrub in a place that holds water and doesn't drain easily. If this is the case, the roots might have 'drowned', being unable to function properly in airless, permanently wet conditions. But the possibly of drought would be a more likely cause.

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