9 minute read
Ask John Negus your questions
from amma e5 7e6y5
by coolkdei2
Removing old and damaged leaves
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Potting up hellebore seedlings
Hellebores are a beautiful and easy-going early spring fl ower
ow can keep hellebores looking good?
QI have lots of beautiful Helleborus nige r in my garden. How can I keep them healthy and help them flower? Angie Bayliss, Penrith, Cumbria
AHellebores will thrive in organically rich, limey soil. If you can’t get mushroom compost, which contains chalk, I suggest you mulch plants with 3in (7cm) of composted manure. You can either buy a proprietary brand from a garden centre, or see if a local farm is selling sacks of selling well-rotted manure. Provided you augment your compost with a sprinkling of 30oz (84g) per square metre of garden lime, and a spring, mid and late-summer application of Vitax Q4, your plants will thrive. Additionally, remove half the older leaves in autumn, and the remainder in spring, just before new foliage and flowers appear. This makes room for new growth and reduces the risk of disease such as leaf spot moving from old to new growth. Leaf spot is a fungal problem that spreads when raindrops splash up onto the leaves from the soil, carrying spores. Symptoms are brown patches of dead material on the leaves that can fall through, leaving the leaves in holes. Stems can also be infected, causing plants to collapse and tiny black fungal structures may be seen. Halt the spread by removing and disposing of all dead and infected material (do not compost) or by using fungicide. Regular mulching also keeps spores buried so they are less likely to be splashed up onto plants. Hellebores are prolific self-seeders, so if one you particularly like is surrounded by its seedlings, pot them up and grow them on before planting elsewhere in the garden.
Are nasturtium seeds edible?
QI have heard that nasturtium seeds are edible. Do you need to prepare them first? Lucy Allbright, via email
ASpicy nasturtium seeds are pickled and served chopped with pasta, sauces, salads and dressings. Gather half-ripe seeds and rinse them. Dissolve a ¼ cup of salt in a quart of water and add ⅔ of a cup of seeds. Keep seeds submerged for two days by covering the container with a zipped plastic bag, pushing it down inside the container. Strain the seeds and rinse to remove salt, then add ⅔ of cup of white vin and one teaspoonful of sugar to a small saucepan and bring to boil for one minute, stirring. Put seeds into ½ pint (450g) jars and cover with hot vinegar. Add a bay leaf to each and let them cool to room temperature before sealing with lids. Pickled seeds can be stored at room temperature or in a fridge. Nasturtium seeds make a good side dish Nandina is attractive and easy to grow
Name this shrub
QA shrub that’s about 4ft (1.2m) tall with reddish spear-shaped leaves is growing in our new garden. Can you identify it please? Andrew Gordon, Basingstoke, Hants
AYour plant sounds like Nandina domestica , or sacred Japanese bamboo. When mature, its white summer flowers are usually followed by large cones of small red berries. A member of the berberis family from India, China and Japan, it was introduced into cultivation in 1804. It has great appeal, and thrives in full sun and is easily propagated from semi-ripe cuttings in summer or from seed.
Many epiphytic orchids produce miniatures called keikis
What’s a keiki?
QWhat is a keiki? I think they are part of orchid propagation. Craig Stewart, via email
AMany epiphytic orchids, especially phalaenopsis, produce keikis, which are plantlets that appear from an orchid’s main stem, or from its flowering spike –not from its roots – and are identical to the parent. If one appears, and you want to detach it, wait until the roots are 2-3in (5-7cm) long, then remove it with a sharp, sterilised knife. Set the plantlet in orchid compost, and care for it as you would the parent plant.
Dividing a mature peace lily
Cut off browning leaves of established peace lilies
How can I revive my elderly peace lily?
QMy relatively old peace lily is starting to look a bit jaded, with a few browning leaves. How can I revive it? Martin Winters, Saxmundham, Suffolk
AMy peace lily has done exactly the same, but after close investigation I found the leaves that were affected had either borne flower stems, were tucked right underneath and lacked sufficient light, or were the oldest and therefore least productive leaves. Dividing peace lilies helps them regenerate. It is some years since I last split mine, so each division is well established and it is quite natural for them to shed some of the older and unproductive leaves to concentrate energy into young and vibrant foliage. It is also natural for the plant to shed the leaves that bore the flower stems –they have served their purpose and can be discarded. There is really nothing to worry about, and the best thing to do is to cut out the yellow leaves as low as you can without damaging the surrounding foliage. Peace lilies are amazingly forgiving of neglect, but will reward you tremendously for a bit of care and your plant looks extremely healthy and shiny – it is obviously very happy in its home!
Will potatoes grow in a growbag?
QIs it possible to cut growbags in half for growing potatoes? Pam Johnson, via email
ACutting a growbag in half and growing potatoes in each is a great idea, though you will need to remove most of the compost first and replace it as your potatoes grow. Make sure the base of each is covered with 4in (10cm) of multi-purpose compost and nestle four tubers onto it. Chit them (sprout them) first by setting the tubers upright with the budded ‘rose’ end on top in seed trays or egg boxes. Place the potatoes somewhere light in temperatures of 50ºF/10ºC and when the sprouts are around ½in (13mm) long, reduce them to two or three. Plant the tubers in mid-March.
Chitting potatoes before planting
Potatoes will grow very well in a growbag split into two
Quick questions & answers
QWhy doesn’t our potted oleander flower? Cecilia Montes, via email
AIt could be down to potassium deficiency, so give the plant a high-potassium feed weekly between April and September and top-dress its pot with John Innes ericaceous compost. Also, prune the plant in spring if it is getting too large.
QIs spring a good time to divide bamboos? Mark Bolton, via email
ASplit your bamboo clump in March or April when soil is warming and night temperatures are higher than they are now and conducive to growth. Before dividing the clump, shorten the section you wish to divide to within 9in (23cm) from the soil.
QHow can I care for my pansies and violas so that they flower for longer? Andrew Marsden, Telford, Shrops
ARemove the faded blooms every week to stop seeds forming and work a slow-release fertiliser such as Osmocote into the soil or compost. This will release nutrients in mild weather, but not when temperatures drop and roots are unable to take in nutrients.
Write to us: Ask John, Amateur Gardening magazine, Pinehurst 2, Pinehurst Road, Farnborough Business Park, Farnborough, Hants, GU14 7BF.
Email us: amateurgardening@ti-media.com
Overwatering and too little heat can cause Clivia miniata to suff er
Can we stop our kaffi r lily fading away?
QHow can we look after our kaffir lily? Its leaves are starting to look withered and yellow. Debbie Unsworth, via email
AThe kaffir lily (Clivia miniata ) is a native of South Africa, named after Lady Clive, Duchess of Northumberland, whose grandfather was the famous Clive of India. It is normally undemanding and delights us with heads of bright orange flowers in spring. I suspect that yours is looking unhappy because you have overwatered it, driving air from the compost. If that is not the cause of its distressed appearance, it may be suffering from too little warmth. If the compost is soggy, push a pencil into the drainage hole to allow air to drive out excess moisture. Ideally, repot it in John Innes No2 or 3, and water only when the compost surface is dryish. Encourage it to flower well by keeping it cool for eight weeks or so from October to December. Then move it to a warm, light room where the temperature doesn’t drop below 61ºF (16ºC). Feed with high-potash liquid fertiliser when flower buds are forming.
Caring for potted daffs after fl owering
QI have 20 pots of daffodils planted up for spring colour. When they have finished I leave them in their pots until next year? Colin Mace, via email A By all means keep your daffodils in their pots to flower next year. All you should do after blooming is to remove faded leaves whe they are brown and dead Simply pull them gently from the bulbs. If they can’t be easily detached cut them off at ground level. Your daffodils will then remain dormant until August, when they start to grow again. Ideally, repot them in a mix of equal parts, by volume, of John Innes potting compost No1 and multipurpose compost. I am assuming that the pots in question have drainage holes. If they don’t, reset bulbs in those that do. Do this when they are dormant, in late spring or early summer. The important thing is to make sure the compost doesn’t become soggy and airless as this will kill the bulbs. Daff odils and other spring bulbs thrive in containers
Worming out casts
QOur lawn are covered in worm casts. How can I get rid of them without killing the worms? Linda O’Farre via email
Worm casts are unsightly and can encourage weeds
AI am sorry to hear about the worms in your garden. Although some are needed to help aerate the soil and encourage a good sward, the best way to reduce them is to feed the grass with lawn sand. This contains sulphate of ammonia, an acid and nitrogenous fertiliser that is disliked by worms, so they move away from it. Apply it every five or six weeks from April until August. Your lawn will be lush, and the worms casts should no longer be a problem.
Celandines are attractive, but can be invasive
Many celandines
QWhat is the best way to get rid of celandines? They are pretty, but are also a pest! Ian Woodward, via email
AThere are three effective ways to control celandines. 1: Fork them out in spring when young and the tiny tubers are firmly attached to the main carrot-like storage organ. 2: Paint leaves in spring with Roundup Gel, a systemic herbicide that travels to all parts of the plant. 3: Cover invaders with weed-control geotextile that excludes light so that growth dies. Ideally, camouflage it with chipped bark. Keep the ‘mat’ in place for a year or so.
