Episode 25: Controlling Vine Weevils and Gardening Jobs & Plants of Interest for April
How to control Vine weevils, our plant of the month; Lamprocapnos spectablis, plants of interest for this month; Uvularia grandiflora and Berberis darwinii and jobs to do in the garden for April.
Download: Episode 25: Controlling Vine Weevils and Gardening Jobs & Plants of Interest for April
File Size: 14.0 MB, Duration: 30' 06"
April is the month probably most associated with spring. March sometimes holds on to the cold and wet of winter, whilst May can be nearly as warm and summer-like as June.
Gardeners always have something to do, whatever the month, but April is probably the busiest month of the year in the garden. It is a month of fresh colour and lush new growth and a month full of the horticultural joys of spring.
How to Control Vine Weevils
The first step in trying to control vine weevils is not to get them in the first place and to this end it is advisable to only purchase plants that are certified to be free of the pest. Similarly, only sterile, pest free compost should be used and any containers used are best cleaned with something like Jeyes fluid prior to use.
Adult vine weevils
- Adult vine weevils are nocturnal and feed on a plant’s leaves at night
- About 1cm long with rough black, textured bodies freckled with rusty-brown spots
- Slow moving and not able to fly, but are good climbers
- Adult females vine weevils lay eggs in soil or compost during late summer and early autumn
- Damage caused by adult vine weevils is mainly cosmetic, eatting unsightly notches around leaf margins
Vine weevil larvae
- Creamy-white in colour, legless and have a distinctive brown coloured head, usually curled up into a c-shape
- Particularly affect container grown plants
- The larvae feed on plant roots below soil level
- Symptoms are not usually evident until the larvae have almost finished feasting and the plant is about to collapse
- Vine weevil larvae particularly like Cyclamen, Begonia, strawberry plants and Primulas
- By early winter, the larvae pupate in the growing medium, developing into the adult weevils
Control
- Collect and kill the slow moving adult weevils from affected plants at nighttime from late spring onwards before they have a chance to lay their eggs
- Place rolled-up corrugated paper affected plants; adult wine weevils take shelter under the paper during the day and can then be caught and destroyed
- Smear vaseline around the rims of containers, preventing access to the adults
- Soil surface of pot plants can be mulched with sharp gravel, providing a physical barrier to the adults burrowing down into the compost to lay their eggs
- Add nematodes, tiny worms that feed on the vine weevil larvae. Only use when temperatures are warm enough during the growing season
- Dispose of the growing medium from affected areas and plant, don’t put this on the compost heap
- Remove any plant debris from around the base of pot plants as this provides daytime shelter for adult vine weevils
- Provado is a chemical control for vine weevils
Plant of the Month
Our plant of the month for April is Lamprocapnos spectablis - Bleeding Heart
- Formerly known as Dicentra spectablis, the plant was renamed after new research into it’s genetic makeup
- Fully hardy, deciduous, herbaceous perennial
- RHS H7: <-20C Hardy in the severest continental European climates
- Height up to 1m, spread 0.5m
- Partial shade, but will tolerate full sun if the soil is moist
- RHS Award of Garden Merit
- Growth Rate: Average, 2 – 5 years to maturity
- Flowers: Bright pink pendant heart shaped flowers with white accents produced on long arching flower stalks above the foliage, April to May
- Foliage: Attractively divided light green leaves with a fern-like appearance
- Soil: moist, humus-rich, preferably neutral to slightly alkaline soil
- Foliage may aggravate skin alergies and harmful if ingested
- Ideal in a shady border, but as the foliage dies back early, plant amongst a mixed summer flowering border for continuing interest
- Propagate by division of the rhizomes in early spring or after the leaves have died back, or by root cuttings in winter
- Maintenance: Easy to grow with low maintenance and generally pest and disease free, mulch in autumn
Jobs in the Garden
- Cut-back Penstemons and Hardy Fuchsias
- Now that the worst of the winter weather is becoming a distant memory, these two borderline hardy plants can be pruned
- Last month the potential for a severe late frost was still there and the top growth of these plants protected the fresh basal shoots
- Cut all of the older shoots down to these young basal shoots this month
- Mulch Borders and Flower Beds
- Mulch this month, with the aim of preventing soil moisture evaporation, locking in moisture from previous months
- Mulching also slows down weed growth if sterile mulch is used e.g. bark chip or Cocoa shell
- Lawn Care
- April is one of the busiest months for lawn care
- Mowing is usually necessary at least once per week in April
- Organic or in-organic feed/weed treatments can be applied
- Lawns can be scarified
- Any winter damage can be repaired with seed or turf
- Herbaceous Perennials
- There is still time this month to split congested clumps of herbaceous plants
- Prise them apart with two forks or divide with a spade
- The centre of the perennial will be the most tired, just keep the outside sections
- Feed roses with specialist rose food
- Dead-head early flowering bulbs
- Keep an eye on night time temperatures and protect the flowers of fruit trees when frost is forecast, using horticultural fleece
- Prune Forsythia and early flowering shrubs as soon as they have finished flowering
- Plant out half-hardy or tender summer bulbs such as Dahlias and Gladioli
- Sow hardy annuals e.g. Clarkia in the border, where you want them to flower
- Plant evergreen trees and shrubs
- Container grown plants can also be planted this month
In the Vegetable Garden
- Sow inside: Runner beans, Tomatoes, Marrows, Courgettes, Cucumbers, Melons, Pumpkins, Sweetcorn.
- Plant out without the need to protect from frost: Early and maincrop potato varieties, Kale, Spinach, Swiss Chard, Calabrese, Lettuce, Globe artichokes, one-year old Asparagus crowns, Peas, Carrots, French beans, Leeks and Onions (seeds and sets)
- Young aubergine plants can be moved to a cold frame this month for hardening off
Plants of Note
Two plants that we felt were worthy of note for this month are:
Berberis darwinii - Darwin's barberry
- Charles Darwin discovered Berberis darwinii in 1835
- Fully hardy, dense evergreen shrub
- RHS H5: -10 to -15C. Hardy in most places throughout the UK, even in severe winters
- Makes a good hedge
- Growth Rate: Average; 10-20 years
- 2.5m tall, 2.5m spread
- Full sun or partial shade; a sunny location will promote fruiting
- Soil: Moist, but well-drained; doesn't like to be waterlogged
- Flowers: Clusters of bright orange-yellow flowers are produced in spring (April to May) and sometimes again in autumn. Large clusters of small, blue-black fruits follow the flowers
- Foliage: Oblong, dark green, leathery, holly-like leaves with a few sharp spines on their margins
- RHS Award of Garden Merit
- RHS Perfect for Pollinators Award
- Maintenance: Low maintenance although May be infected by powdery mildews. Requires minimal pruning; best pruned in autumn or winter after fruiting
- Propagation: Propagate from seed or from semi-hardwood cuttings
Uvularia grandiflora - Bellwort
- Also called: Cornflower, Large-flowered bellwort, Merry bells, Throat root and Wood daffodil
- Fully hardy deciduous herbaceous perennial
- RHS H5: -10 to -15C. Hardy in most places throughout the UK, even in severe winters
- Growth Rate: Average to Fast, 2-5 years to maturity
- 1m tall, 0.5m spread
- RHS Award of Garden Merit
- Full shade or partial shade
- Soil: Moist, but well-drained, fertile, humus rich soil
- Flowers: Narrow bell-shaped yellow flowers with twisted tepals on arching stems
- Foliage: Bright green, lanceolate shaped leaves
- Maintenance: Low maintenance, although slugs and snails could be a problem
- Propagation: Propagate from seed or by division in early spring
Forthcoming Garden and Flower Shows
- 14 - 15 Apr: RHS Great London Plant Fair 2015
- 17 - 19 Apr: RHS Spring Flower Show Cardiff 2015
- 23 - 26 Apr: Harrogate Spring Flower Show 2015
- 27 - 28 Apr: RHS London Botanical Art Show 2015
Useful Links
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