Trees & Shrubs FAQs
Can you please tell me how to get rid of Bamboo roots when they have been cut down to ground level?
When should I cut my Hebe bush back and how hard?
Can you explain please why our Hydrangeas do not flower but look otherwise quite healthy?
I have a Camellia that I have had for several years.It was fine at Christmas with lots of flower buds .In January I noticed the leaves were covered in a black powdery mould. Can you help?
Your Camellia is suffering with sooty mould, this is a fungus that grows on the sticky residue secreted by sap sucking insects ( Aphid, black fly, scale insect etc.) Camellias are particularly prone to Scale insects, these (as the name suggests) look like scales or flattened wax blobs usually found on the under side of the leaves. The first step is to treat the plant with an insecticide to kill the bugs (I suggest Provado Bug Killer) , It will then be possible to clean off the sooty mould without it reoccurring.
Can you please tell me how to get rid of Bamboo roots when they have been cut down to ground level?
Having cut the tops off, you don't have the option of using a weedkiller [it would need to go into the leaves] so I suggest that you dig them out. This will be very difficult so it is worth considering hiring in a stump grinder in.
Having kept Rhus (stags horn sumach variety) for several years now, could you please tell me approx how deep the roots extend. I know from experience that the plants spread via underground runners and that the root system can cover a vast area;
Rhus has a very extensive root system that often exceeds the spread of the branches by at least 50% of their width. However, the roots are generally very shallow and consequently less likely to get into drains. It is unlikely that the roots will venture into the sub soil and your drains should be down in that lower level of soil. Damage to the roots of the common Rhus typhina generally leads to suckers being produced but the very finely cut leaf varieties seem to have much neater root systems and rarely produce suckers. I would always recommend the cut leaf variety for this reason.
I was wondering if you could please provide me with some information on the propagation of Hawthorn, ie from seed, cuttings etc?
Hawthorn is propagated from seed or is budded onto seedlings of hawthorn in the case of selected named varieties. It is extremely difficult to root cuttings. Seed is collected when the haws are ripe, the fruit is removed by maceration and then the seed is either sown outside and will usually germinate in the second spring after sowing or more likely stored by mixing with a mix of peat and perlite at just above freezing until early spring. If sown then, this chilled seed will germinate within a few weeks. Incidentally, we sell hawthorn seedlings during the winter for hedging and they are so cheap that you may not bother to sow your own!
We have recently sold our house and I wish to take some shrubs out of our garden to our new property. Can you advise me how I should move my shrubs especially as it may be some time until I can plant them at our new property? (November)
Many shrubs will move well now (November) but you will need to dig evergreen plants out with a rootball of earth, wrap it in sacking and keep wet until replanted. It will help to prune the top back by about 25%. Those shrubs that lose their leaves will generally transplant more easily but they will move more successfully if some of the leaves are removed beforehand. I suggest that you prune out old wood and shorten soft new growth back too. This will help to restore the root to shoot balance which will be out of kilter as you will be bound to leave quite a lot of root behind. Remember that it is the fibrous roots that are the important ones and they have the ability to grow and get your plants established. Establish all in large pots with good potting compost and keep the plants in shade and well watered. Purchasing some shade netting may be worthwhile and this can be used to shelter the plants in their new position in your new garden until fully established. Naturally, you will need to prepare the planting holes well by adding some organic matter, general fertiliser and finishing off with mulch. Watering well until established is vital and this may be needed even in winter. One final point, you may need to let the prospective buyer know which plants you are taking with you. Your estate agent will advise on this.
I'm looking for an unusual climber for a trellis on decking. The spot is west facing, with dappled shade and I would like an evergreen. I want something different, maybe with catkins or variegated leaves or change of colour but not clematis.
Your request for evergreens limits the choice a bit but for catkins try either winter flowering Garrya elliptica (male form) or summer flowering Itea illicifolia. For interesting flowers try the Coral Vine (Berberidopsis corallina) or the more common Trumpet Honeysuckle (Lonicera sempervirens). Both have striking orange-red blooms. You could plant the evergreen Hydrangea seamanii or Pileostegia viburnoides, both are self clinging climbers with dainty white lace-cap flowers. We stock these varieties but they are not widely available everywhere.
I have a large lavender bush in full flower, which has also become very woody over the years. It looks okay from the front, but is a mass of exposed growth from the rear of the bush. Should I remove and replace?
Your lavender may not shoot from old bare wood so rooting a cutting before you chop it back now is a good ploy. You then have a young plant to put in if the pruning kills the old plant. Late summer is a good time to root Lavender cuttings.
I have a pink Hebe in my front garden and it has got rather woody and straggly. When would be the best time to take a cutting?
Your Hebe should root easily from semi-ripe non flowering shoot tips of about 4" long. Late summer to early autumn is a good time to propagate evergreen shrubs by taking cuttings. You may find that it will root without using hormone rooting powder but by using some, the roots appear more quickly and consequently there is less chance of the cutting perishing before roots grow. Do buy fresh hormone rooting powder as it quickly loses its' effectiveness and is best stored in the fridge.
When should I cut my Hebe bush back and how hard?
The best time to cut Hebes back is in spring. However, they don?t always shoot from bare wood so it is better to cut them back a little every spring rather than wait until you have to drastically prune. If you have to cut hard, root a cutting before you do so in case the plant dies. You can then replant the cutting. It is best to regard Hebes as relatively short lived plants and replant when they look scruffy.
My wife has two Clematis montana ('Elton' and 'Freda'). In large pots and were a gift to her last year as new plants. Whilst they both look healthy and are in half sunlight, fed and watered regularly, neither have flowered. Can you advise?
Clematis montana varieties are very vigorous climbers that flower on last years stems in spring, so it is possible that they were cut back just before they were bought for her, hence no flower this year. Keep well fed and watered and plant out in to the ground if at all possible. They will probably flower in May next year but are rather vigorous for pots.
Can you please tell me what the little limpet like bumps are on my plant? The plant is growing on a south facing wall. Do I need to treat it and, if so, what with?
Your plant has Scale Insects and certainly needs treating! If this is an ornamental plant, spray two or three times with Provado Bug Killer. If a food producing plant, please advise variety for further advice. There is now a natural predator that you can send off for to control this all too common pest. We can organise this for you at Cleeve Nursery.
I have powdery deposits on a Clematis. I have sprayed it but now given up and cut it down. Is there anything I can do?
It sounds as if your Clematis had powdery mildew and that can be hard to control. This is often worse when it is hot and dry and your plants are stressed. Try to keep them well watered and fed, clear away any fallen leaves as they may harbour spores to re-infect your new shoots next year. Shade the roots with an evergreen plant or a large flat stone. If you spot an early infection spray immediately with a product such as Scotts Fungus Clear to protect new leaves from attack.
I have two new roses which are being eaten by something. It looks like a cut that you see from leaf cutter ants. Do you know what this is and how can I prevent losing my favourite climbing roses?
This is, I suspect, caused by the Rose Cutter Bee and may be getting more of a problem. Generally, if your plant is well established, the few leaves that it neatly cuts and takes away to roll up as a kind of nest will only have an unsightly impact on your plant but, if it is a small plant you need to take action. A general insecticide such as Provado Bug Killer will probably control this one but do weigh up whether a few lost leaves are worth tolerating when balanced against the immense benefits that bees have to gardens.
Can you please tell me how much woody herbs such as lavender, hyssop and thyme should be cut back and the best time of the year to do this??
Lavender is best cut back after the flowers start to fade. Cut back each flower stem removing a small part of the leafy stem too, but don't cut back into woody leafless stems unless the plant is still young. Hyssop and Thyme can be trimmed now or in early spring. I favour now as they seem to produce new growth more readily at this time especially if given some feed now too. There comes a time [no pun intended] when thyme is reluctant to shoot again and is best replaced with a fresh plant or with a cutting rooted from your old plant.
Please advise on plants I can put under a large Magnolia tree, laurel and other shrubs in a border? It is shaded by a wall to the south so gets minimal sun, if any. There is a lot of ground to cover and I would like something low maintenance.
Try Periwinkles, especially Vinca minor Bowles Variety [blue] or Alba [white] (5) or Cotoneaster dammeri (3), Hardy Geranium macrrohizum (4), Lady's Mantle {Alchemilla mollis} (4) or for really tough areas Euphorbia robbiae (4). The numbers in brackets indicate how many to plant per square metre. All are easy and low maintenance.
I have two tree peonies which have produced growth at the base, which look like the ordinary bush peony. Is this lower growth "suckers" and should it be removed, in the same way as rose suckers?
This is almost certainly suckers from the rootstock or root system of the plant. As tree peonies are rather difficult to propagate from cuttings they are grafted onto a species or variety that is easier to multiply. Grafting itself is a skilled operation and requires much practise. This is why grafted plants tend to be more expensive. The down side is that they sometimes produce these unwanted shoots. They should be removed at the earliest opportunity as close to the root system as possible. If just cut off at ground level, the tendency is for dormant buds left at the base of the shoot to wake up and before you know it there are lots of suckers not just one! Other plants that should have suckers removed at this time of the year include Viburnums, lilacs, roses, witch hazels, maples and even most young trees.
I have had Clematis 'Niobe' and Clematis 'Lasurstern' in large containers for eight years or more. They have been most successful but in recent years with less and less flowers.
For best results top-dress the container in spring with a good fertiliser like Vitax Q4 and feed during the season with Miracle Gro. I recommend repotting into fresh soil based compost in early spring.
I am looking for a colourful climber (not white) to be planted in the corner of the garden to climb up the fence. This particular part of the garden is rather shady.
Try the honeysuckle called Dropmore Scarlet or sempervirens. Both thrive in the shade and are red flowered. Berberidopsis corallina is another, but unusual, climber that does well in shade but this one prefers an acid soil.
I planted a Wisteria in my garden five years ago and it still hasn?t flowered. When will it begin to flower and is there anything I can do to make it flower next year?
Wisteria can take a while to settle down and flower but this will take longer if you a have bought a plant that is a seedling and not propagated as a graft or layer. The reason for this is that as a seedling it is still a youngster and not yet mature but as a grafted or layered plant it has already gone through the juvenile period and should flower within two or three years. Wisteria must have full sun and good drainage. Flower buds will be encouraged by summer pruning in late July or early August. Shorten back all new growth to within a secateur length of where growth started that year. This gives the plant quite a shock and triggers flower bud initiation.
I was given a Camellia plant for a recent birthday present which is already in a pot. What is the best location for the placing of it? Advice on care and feeding of it?
Virtually all Camellias are actually quite hardy, but their flowers are frost tender, so growing it outside should not be a problem at all. The exposed location could mean that the blooms get bruised and go brown [this is what happens when they get frosted too] but the leaves are very wind tolerant and Camellias can be seen used as wind breaks in Cornwall. Avoid positioning your plants where the morning sun falls directly onto the plant, the sudden thawing of the blooms after frosting causes the cells to rupture and go brown. A gentle thawing may be tolerated without too much damage. Camellias prefer a compost or soil with very little lime in it so check your soil's pH [you can get a tester from most garden retailers]. If above pH 6.5, add moss peat, pine bark or another acid compost or perhaps sulphur chips. If growing it in a pot, use lime free, sometimes called 'Ericaceous' compost. They make excellent container plants! Feed with Miracle Gro Ericaceous Plant Food during spring and summer. Never let the rootball become too dry, especially in June to July when the new flower buds form for next spring. They will tolerate full sun but the leaf colour is richer if they have some shade.
Up until last year we had a beautiful Lavatera which we had nurtured for many years to block out an unsightly area behind the house. Last year, half of it just shrivelled and died along with half a Hazel, another smaller Lavatera and a Buddleja.
It certainly sounds as though you may have the fungal disease honey fungus in your garden but I can't be absolutely sure. Lavatera and Buddleja can be relatively short lived and can also suffer from their roots being snapped off if the top sways around a lot. On the other hand, hazel is very long lived and not especially prone to this disease. Although honey fungus has a "sweet name" as you put it, I doubt that many gardeners who have it in their garden would be so polite! It is extremely difficult to get rid of it and attacks a very wide range of woody (but not herbaceous) plants. Incidentally, the name comes from the honey coloured toadstools that sometimes appear in autumn. The other thing to look for is black bootlace like strands growing under the bark of the host plant. I don't think that there is now a product available to the amateur to treat this one but you may be able to get a contractor to do it for you. Some plants show some resistance and to screen your unsightly area try laurel or yew, they may not be as pretty but should survive.
Could you please tell me if it is possible to take cuttings from my Leylandii trees to bring on, and if so how do I do it?
Leylandii is in fact always propagated by cuttings. They are taken in the autumn using a semi-ripe cutting of about 10-12cms long with the bottom of the cutting having just a little brown wood. The lower side branches are stripped off to 'wound' the cutting and this helps roots to form. Fresh hormone rooting powder or liquid should be applied to this wound and the cuttings inserted in trays or pots (in a greenhouse or conservatory) filled with compost such as 50:50 mix of vermiculite and bark. Providing heat to the base of the pot or tray helps a lot and the top should be kept moist and cool, covering with very thin polythene or horticultural fleece might be sufficient to reduce water loss until new roots form. Roots will form in 2 to 3 months but not every cutting will root. You will then need to grow the rooted cuttings on in pots for a year or so before you can safely plant them out. Masses of conifers and evergreens are propagated this way. Whatever you do, bear in mind that this is a very vigorous plant and be prepared to trim it regularly. It will make an excellent fast growing screen or hedge if cared for properly.
Can you explain please why our Hydrangeas do not flower but look otherwise quite healthy?
Perhaps you are pruning your plants too much? Hydrangeas generally produce flowers on older wood and, if all shoots are pruned hard regularly, the flower buds are pruned out too. Hard pruning also encourages soft vigorous new growth that is less likely to produce flowers. It could also be that the plants are too heavily shaded, even though they enjoy some shade, or that they need a dressing of a high potash feed such as Sulphate of Potash and a liquid feed like Phostrogen.
Can you please recommend a shade loving climber? We would like to cover a high wall, 3ft away from our conservatory which receives full daylight but no direct sun. It is a sheltered spot with good moist soil.
Apart from the obvious range of ivies to choose from I would suggest either an evergreen climbing Hydrangea [H. seamanii] or the deciduous one [H. petiolaris]. Alternatively, if the soil has a low pH, and is therefore acid, you could grow something rather different -Berberidopsis corallina which is evergreen and very attractive on bloom. If the wall is short [say 4ft] you could grow the winter Jasmine and a 'Japonica' [Chaenomeles] together. This would give good winter and spring colour but would require some attention to train them as they are not true climbers. With whatever you plant it is well worth considering planting a Clematis too so that the period of interest is extended. Pale coloured Clematis from the large flowered groups look at their best in shade.
I have two rose cuttings which were rooted in water (as done with Busy Lizzies for example). Please can you tell me if this is a recognised way of propagating roses and are they likely to be more susceptible to disease?
Roses are budded or grafted onto rootstocks of a form of briar rose to control the vigour of the variety. However, those rooted as cuttings and grown on their own roots often perform well in the garden and have the distinct advantage of not producing suckers of the unwanted type. Often gardeners will root cuttings from a cutflower rose variety,especially if they have a connection with a particularly important occasion, and these often do not perform well (they sometimes lack winter hardiness having been grown under heated glass or imported from East Africa). Good luck with growing yours on!
I have been looking for a plant called the New Zealand Christmas Plant or Pohutukawa. I'm told that it is hardy in this country and it grows on the coast in New Zealand. Where can I get one?
This is Metrosideros and occasionally seen in gardens in the south west and up the western side of the UK and Ireland. It is a spectacular tree or large bush in bloom but won?t stand lots of frost. The flowers are bright scarlet and can cover the tree in late winter. It is quite salt tolerant so might perhaps be grown close to the coasts where frosts are less likely. In Shepton Mallet you will be taking a chance growing it but as they say nothing ventured, nothing gained! The best place to find an uncommon plant such as this is to search on the Plant Finder site of the Royal Horticultural Society http://www.rhs.org.uk