Ask John Negus your questions

Mr Fothergill’s

Dormant clematis look ‘dead’ (inset) but will rejuvenate in warmer weather

QI have several clematis in the garden and overwintered in my greenhouse, including a ‘John Huxtable’, but they just look like dead stems. What should I do? Mrs A Crookes, via email

AI wonder if it is simply a matter of time. A simple way of checking whether the stems are still alive is to scrape away a sliver of the bark using a thumbnail. Live stems have green flesh under the bark, dead stems are brown. Varieties like ‘John Huxtable’ flower later in the year on the current season’s growth, so are unlikely to be showing signs of bud burst yet. Second, all the advice given with new

clematis plants is not to expect too much in the first year or two as they will be establishing strong roots and may not do too much growing on top. In year three they will start to perform. I shouldn’t think incorrect planting is the problem here, but just in case, you can try the guide at:  https:// taylorsclematis.co.uk/plant-care.html . Most clematis are fully hardy so they should not need any winter protection, though plants in pots are more vulnerable to cold than those in the ground. However, a frost-free greenhouse should be all that is necessary. I’m sorry I don’t have an exact answer to your question, but I hope that this information is reassuring.

QThe leaves of our bay tree are covered in strange marks. Would it help if I pruned it back? Nigel Clark, Letchworth Garden City, Herts

AThe marks on the bay tree leaves may be caused by scale insect, a sap-sucking pest that can weaken a tree. If this is the problem, spray the tree with a mild solution of washing-up liquid or a proprietary organic insecticide. Several applications will be necessary to catch the juvenile stages of the insect. Alternatively, the problem may be the fungal disease leaf spot, which shows as necrotic grey or brown spots on the leaf. The best way to deal with it is through good hygiene and improved growing conditions. Remove affected leaves and rake up fallen leaves. Feed the plant a balanced fertiliser early in spring to encourage new growth. Bay trees respond well to pruning. In late spring, cut the main stems back, some to soil level, and others by up to half to encourage new growth from the base. Bay scale is a sapsucking pest that can weaken plants

Feed strawberries in spring when things are warming up

QDo alpine strawberries need special care now? George Roberts, Meols, Wirral

AIdeally, feed your strawberries in April when the soil is warming up, with Vitax Q4. Apply it monthly until August, sprinkling it over the root area, and watering it in if the soil is dry. Alternatively, use fish, blood and bone meal at 4oz (112g) per square metre, working it into the soil’s surface. Again, feed monthly until late summer.

Plant out foxglove seedlings in late spring

All photographs TI Media unless otherwise credited Q How should I care for my foxglove seedlings? Janet Savage, via email A When your seedlings are 3in (7cm) high, pot them separately into 3-4in (7-10cm) pots of multi-purpose compost. Keep them in your cold frame, protecting them if hard frosts are forecast, and transplant them outdoors in April or May 8in (20cm) apart each way. They will develop a rosette of leaves this year. Because they are biennials, they will flower, set seed and die the following season. Feed them monthly, from April to September, with fish, blood

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Cyclamens are the little jewels of a pot or shady garden

QHow should I plant up hardy cyclamen? I’d like to grow them in an old sink on the patio. Ruth Winterburn, Hampstead, London

AWhat a lovely idea. Cyclamen will add much in the way of foliage interest as well as long flowering. Producing small pink shuttlecock-like flowers, they are one of my favorite plants. Ensure you use a soil-based compost such as John Innes No2, to which I add 25% sharp alpine grit, as the corms will rot if they sit in wet conditions over the winter. Put plenty of drainage in the bottom of the sink.

Both Cyclamen coum and C.

hederifolium can be grown very

Morguefi le successfully in a sink, but don’t plant them together as C. hederifolium is the more vigorous of the two and will smoother the coum and kill it out. Once established, these plants

will seed themselves into the sink making a beautiful display with time.

QWill the stone from a supermarket mango grow successfully in this country? If so, what compost should I plant it in? Jerry Bryan, via email

Mango trees will grow indoors, but are unlikely to fruit

AMango trees can be grown as houseplants here, but are unlikely to produce fruit as they need a minimum winter temperature of 16ºC (61ºF). Use a pan scourer to scrape away the remains of any flesh and rub the seed with sandpaper to make water absorption easier. Place the stone in a jam jar of water and put it in a warm place, such as an airing cupboard. Change the water every day for two weeks and if the stone sprouts, remove from the jam jar and place in a 4in (10cm) pot of compost with the shoot uppermost. Keep it somewhere light and water frequently. If it doesn’t shoot in the jam jar after a few weeks, pot it up by laying it horizontally in the compost and put the pot in a plastic bag. Seal it and return it to the airing cupboard for up to two months and, if kept warm and damp, it should eventually sprout. When it does, remove from the bag and place in the light. Continue to pot on the seedling as it grows and after the first year pinch out the top bud to keep it bushy. Mango trees like to be watered with rainwater and fed once a week in the summer.

QPlease could you identify this plant? Colin Turner, Tiverton, Devon

AThe climber in question appears to be a Chilean trumpet creeper. There are two principal species, Campsis chinensis and C. radicans , and a hybrid called C. x tagliabuana ‘Mme Galen’. It is normally self-clinging, but the sucker-like adventitious roots on the stem shoots may require tying in when young.

QWhat is this growing at the back of our garden? Ann Marie Tucker, Weston-super-Mare Somerset

AThe mystery plant is teasel (Dipsacus fullonum ), formerly used for carding wool. A handsome British wild flower –a biennial that forms a rosette in its first year, then blooms and dies in its second –its pinkish-purple blooms are followed by seeds that goldfinches adore.

QI’ve been trying to identify this plant, which is growing in a container left out after last year’s petunias. Any suggestions? Susan Barnes, Thorney, Peterborough

AThe plant in question is Montia perfoliata and is also called Claytonia perfoliata . A native of North America, it was introduced to Britain in 1749 where it has become naturalised. Its tiny white flowers, in the centre of ‘perfoliate leaves, have great charm. A woodlander, it romps in light shade.

Seedlynx

Choisya and daphne (left) are good choices for dry, shady areas Grow sweet peas in new soil or compost each year

QI have a 12-15in (30-45cm) strip of border that has a brick wall one side, a house wall on another side and block-paved drive on a third side. The soil is mostly very dry due to a slight roof overhang. Can you suggest a suitable evergreen shrub that will get to around 6x3ft (1.8x1m)? Mark James, via email

AThere are several contenders for the situation. Initially, because the site is in a ‘rain shadow’, work in lots of moisture-conserving composted manure mixed with fish, blood and bone meal. Water well in dry spells. The following would serve you well: Cotoneaster lacteus : Milky-white flowers followed by crimson berries. Euonymus japonicus ‘Aureus’: Golden variegated leaves. Cut out green-leaved reversions.

Choisya ternata : Commonly called Mexican orange, a wealth of creamywhite flowers sleeves shoots in spring and early autumn. Escallonia ‘Slieve Donard’: Appleblossom-pink flowers in late summer. Daphne bholua ‘Jacqueline Postill’: Richly perfumed purple blooms in late winter. Camellia x williamsii: ‘Donation’: Semidouble, peach-pink flowers in April. If the one you choose outgrows its allotted space, trim it after flowering.

QOur new container rhododendron is losing its leaves. Can it be saved? Paul Michaels, Bury, Lancs

AThe usual reasons for leaf fall are that the compost has dried out or leaves have succumbed to disease. In this case, I suspect the former, although it may have been stressed before it was purchased. If your soil has an acid pH, transplant it into a well-prepared and humus-enriched border. Water copiously. Hopefully, if its falling leaves are healthy they will, in spring, be replaced by strong new growth. If your soil is alkaline, grow it in a large pot of ericaceous compost with added grit. Feed monthly when

Rhododendrons will thrive in borders and large containers

QHow can I stop my sweet peas falling foul of a virus? I have to grow them on the same site each year. Terry Stewart, Gloucester

AYour sweet peas are succumbing to virus disease because, for practical reasons, you are unable to grow them on a fresh site each year. At RHS Garden Wisley, the sweet pea area is rotated annually. In the second year, paths between rows are dug and manured, and beds become paths –a procedure that is repeated each year. As you cannot change the site, you could either replace soil with fresh, from another part of the garden, or grow your plants in half-barrels or large pots.

QWhat is this plant growing up a Alamy

fence in my neighbour’s garden? It has been there for years, but she does not know what it is. Vanessa Marsh , via email

Ornamental raspberries make attractive climbers

AThis appears to be a form of ornamental raspberry, botanically called Rubus rolfei. This is a creeping alpine evergreen which, when confronted with an obstacle such as a fence, has no problem ascending it. Summer sees single or clustered white flowers that occasionally produce edible fruits. It is very similar to ‘Betty Ashburner’, a variety that results from crossing R. rolfei with R. tricolor, the latter of which is a vigorous western Chinese species introduced to gardens by the plant hunter Ernest Wilson in 1908.

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QI have filled a raised bed with reused compost and manure. Can I add leafmould and ‘clean’ used compost as well? Maria Mason, via email

ALeafmould is fine to add to your raised bed. The micro-organisms that break down the tough leaves are different from those that work on softer, greener materials, but all are present in compost so it shouldn’t take long for decomposition to be completed. The issues about reusing potting compost are three-fold. The first is the likelihood of transferring soil-borne pests and/or diseases to other plants. Vine weevil is a particular concern, but fungal diseases like damping off and some vegetable diseases can be a source of infection. However, you mention that you don’t add any used potting compost until you are sure it is clear of problems so hopefully this won’t become an issue. The second aspect is one of nutrientavailability. Peat and peat-alternative composts only contain enough nutrients to feed plants for about four-six weeks.

Well-rotted leafmould, compost and manure are wonderful additions to a raised bed

After this we need to think about liquid feeding to keeping our plants strong. However, adding organic matter such as well-rotted garden compost and manure will give the mix a boost. The final consideration is the structure of the mix. Peat and peatalternative composts, being organic matter, tend to break down over time and lose their structure. Mixing old compost with other materials does help, but it might be worth adding some loambased material for longer-term benefits.

QWe have just moved house and we have a beautiful beech hedge. I would like to add some climbing flowers to it, but what would work best? Karen Crolla-Barker, Blackburn, Lancashire

It’s a good idea to make your beech hedge more colourful with climbers,

but unwise to plant roses and other

woody contenders. Shoots will protrude

and make clipping difficult and your

hedge, in competing with one or more

climbers, will suffer.

I suggest you use annual climbers, such as Asarina antirrhiniflora , whose cascading stems are sleeved with Alamy

snapdragon-like flowers; Cobaea scandens , commonly called cup-andsaucer vine, whose purple bell-shaped blooms are impressive; black-eyed Susan (Thunbergia alata ) yielding pretty, flat, yellow or white black-eyed blooms; and bright-yellow canary flower (Tropaeolum peregrinum ). All should be raised from seed in March and transplanted after frosts in

Canary fl ower or cup-and-saucer vine (inset) will grow well through a beech hedge

QOur Coronilla valentina ‘Citrina’ suffered in last year’s drought. Should I chop it right back now? Jennifer Walker, via email

Plants soon recover from a drought year

AI am sorry that your coronilla suffered from drought last summer. Pleasingly, it is amazingly resilient and will, I feel sure, recover. In spring, when new shoots burst from live tissue, shorten dead stems to healthy new shoots or to near the ground if there aren’t any. Cut back strong healthy stems by half, too. Thereafter, encourage robust growth and a wealth of blooms by feeding monthly, from April to September, with a general fertiliser, such as Vitax Q4.

Bear’s breeches is attractive, but can be thuggish

QWhat is this attractive but rather large plant is growing in our new garden? Diane Cairns, Burnley, Lancashire

AThis is a species of bear’s breeches (Acanthus). Yielding spikes of hooded purple and white flowers in summer, above architectural foliage, it is a magnificent herbaceous perennial. Ideally, move it to a bed or border in full sun or light shade. Do it when the soil is crumbly and ‘open’, neither frosted nor soggy. The only problem is that when you lift the plant, roots left behind will produce strong new and invasive growth, so take care. Ideally, set it to create a 6ft (1.8m) feature well away from other plants, which it is liable to engulf.