Advice, Tips and Jobs For January
ADVICE, TIPS AND JOBS FOR JANUARY
By Howard Drury
With the mild weather and associated gales and high rainfall continuing well into January 2020, I have had to stand back and look long and hard at the jobs for this month. I’ve revamped and expanded my jobs for January, if you have an old copy please discard it as there have been many changes not least in the chemicals available and their uses (Several were withdrawn from sale on 1st of November 2015). Traditionally January is a time to plan ahead with seeds and plants to order The weather can vary dramatically and quickly this month it is this that largely determines what gardening may be possible. Therefore, the list below will vary year to year according to weather especially if the cold start to the month continues. I have also taken into account the effects of so called global warming, including new jobs being brought about by the wetter seasons, the milder and very changeable winters.
The list is based on the South Midlands and will need amending according to where the reader lives. Some tasks mentioned may not be possible until six weeks later for those living in Scotland for example. Keep off ground that is wet and/or frozen. Years of work cultivating the soil can be destroyed in just a few careless moments. Plants are best left to fend for themselves during inclement weather, unless frost protection is being provided. Jobs will also be dictated by trends in the garden market and in design. 2016 could become the year of fruit and vegetables in the form of the potager garden with a few flowers to add colour and help pollinate crops after last year’s bee population decline!
On the worrying side is evidence of something killing conifers in more than one garden in Wolverhampton. The RHS and I agree there is no sign of conifer canker on samples we have inspected. Aphids were present and the ground was very acidic and very dry. Now a specimen above an underground spring has shown similar symptoms. This may be something new or a combination of several factors such as a couple of very dry seasons or severe competition for water and nutrients as the trees were around 90 years old and very closely planted.
Each year I spent some time trying to gauge which jobs need doing when and this is really the art of gardening, however the very wet cold late autumn and early winter has meant that many jobs are either well behind or impractical to carry out. Because of my wet ground my lawn is in places full of moss. The ground is far too wet to carry out any treatment and my advice would be to keep off the ground whatever jobs you are thinking of doing if you have any doubt that you might be causing damage to the soil especially if your garden has flooded in recent months.
I would recommend going around your garden examining each border in turn and when necessary try and aerate any ground that seems unduly wet by using a fork to gently lift the soil and introduce air and at the same time allow drainage. Should extreme cold weather conditions threaten it is well worth having course organic mulch material available to protect the roots of less hardy plants and newly planted subjects, especially evergreens as the frozen ground can prevent moisture uptake which during periods of prolonged frosty weather can cause the death of plants by drought. This is why the better nurseries such as Ashwood will take susceptible plants into protected conditions.
December has always been a quiet month for questions and giving advice but it seems a lot of people are very interested in planting soft and top fruit and January is the time to get started. Other people seem extremely concerned about the recent wet weather and flooding in certain areas of the country with quite a few people complaining that it is worst on clay soils and with this in mind I’ve prepared two extra fact sheets which are available on my website the first is a list of plants for damp soils and wet sites while the second is a list of plants that will either thrive or tolerate being grown on clay soils. Simply type in either title into the search box and press enter to locate the factsheet which can be saved or printed out.
My advice to people planting this month, especially those gardening on wet soils would be to add plenty of gritty sand and to plant as high as possible. I’m also recommended that people plan and build raised beds for many subjects including those ornamentals that need drier conditions, fruit and vegetables. I would however not advocate the use of wood as the wet conditions cause it to rot more quickly. I would recommend thoroughly the use of Link a Bord which is made from recycled waste plastics.
With the massive increases in food prices over recent months my final piece of advice this month is to plan, plant and grow your own fruit and vegetables. Not only will this save money and give you satisfaction of knowing how the crop is been grown and what treatments have been given but it will also reduce the risk of ingesting pesticides as a recent survey showed that every single person examined had a noticeable amount of pesticide residue in their body and recent reports have linked one pesticide with the decline in the bee population due to them losing their sense and ability to find their way home. There are now worries that this same pesticide may be causing the massive increase in dementia in human populations – let’s hope accurate evidence can confirm or deny these accusations. Meanwhile get growing your own – you know it’s safe and I am sure it tastes better!
if like me you’ve piled the pounds on over the Christmas period, thanks to my wife’s great cooking and by sitting around too much then simply get out into the garden, enjoy a few winter gardening tasks and lose weight at the same time, what’s more the colder the weather the more calories you will burn off but don’t catch a cold and don’t overstretch yourself.
I often suggest tidying up the garden after Christmas and while some of you will want to cut off the old foliage from around the deciduous hellebores it is a balancing act between tidying up generally and leaving less habitat for pests such as slugs and snails or leaving enough protection in the form of old stems and plant debris to encourage a wide range of insects and other wildlife some of which will be beneficial and others less desirable. These can all form part of the valuable food chain especially for our birds.
Birds are now suffering tremendously from a shortage of especially berries and seeds, the latter can be easily supplemented by purchasing good quality bird food. The wet weather is also made it difficult for our birds to survive using up more energy in trying to keep dry and warm so extra food at this time particularly this year will be appreciated.
The mild wet late autumn has meant that many growers have been unable to lift deciduous plants such as hedging trees and shrubs along with field grown roses. Most nurseries have now caught up and you will find an excellent selection of deciduous plants in most good garden centres and nurseries. These are best planted as soon as possible to allow them to build up fibrous root system before they come into leaf. The art to for the home gardener will be to juggle the urgency of planting with the care that is needed to plant when conditions are acceptable and not too waterlogged or frozen.
January often sees the first of the new season’s hellebores coming into flower, many are earlier and taller than normal due to the mild autumn last year. In recent years there have been huge steps in the introduction of hybrid evergreen varieties. These produce a multitude of flowers and are much more vigorous than the common Christmas rose, Helleborus niger. Ashwood nurseries are also introducing several new exciting strains of their legendary Helleborus hybridus groups under the titles of H. h. Sunrise, H. h. Sunset and H. h. Daybreak strains; these encompass new colour breaks and are bound to be in very short supply following their introduction this spring.
The appalling growing season last year is bound to lead to poor seed harvest crops and poor germination viability tests. This in turn will in no doubt lead to a shortage of seeds both on the seed racks of our garden centres and in the mail order catalogues so I would recommend purchasing your seeds as early as possible.
By early January many of the local garden centres should be well stocked with a variety of summer bulbs and potato tubers. The dry summer followed by wet weather in Scotland has meant a much reduced harvest for the seed potato growers, which in turn means we might see a slight increase in price but a very definite reduction in tubers size and overall availability. With this in mind I would suggest making your purchases as early as possible in the season.
THE FLOWER GARDEN
Sow seeds of Androsace, allow seeds to freeze out of doors, and then bring the pots into a position with temperature of 7°C (45°F). Leontopodium and Aubrietia can be sown in cold frames towards the end of the month.
Prepare new and existing beds for planting by incorporating well-rotted compost or manure, but not when the ground is frozen. However frozen ground may aid the transporting of compost and manure, in anticipation of better weather. Continue winter digging of all areas when conditions permit.
Early in the month there will be the possibility of transplanting or separating larger clumps of aconite’s which seem to re-establish well if transplanted at this time of the year.
Most herbaceous subjects except those, which flower in early spring, can be divided at this time of the year soil and weather conditions permitting. Always discard the older centre portions of plants where sufficient stock is available.
Plant trees and shrubs and roses during mild spells, but only when ground conditions are suitable. Do not plant if soil is wet and sticky or if frost/snow is lying on the surface. If conditions are unsuitable for planting, simply heel bare rooted plants in. Examine recently planted trees, shrubs and roses, re‑firm ties etc. as necessary, but only carry out this work when the ground is fairly dry. There are plenty of alternatives to peat for improving soils prior to planting. On heavy soils use coarse gritty sand to hold the soil open for many years rather than organic matter which literally rots.
Make up seed orders as quickly as possible, and either visit the better local garden centres or send to reputable seed companies alternatively order by phone or email. Study lists of new cultivars and order new plants, specifying delivery times.
Prepare areas for outdoor Chrysanthemums or Dahlias by thoroughly digging planting areas, adding generous amounts of well-rotted farmyard manure or home made compost. Where quality blooms are required the soil should also be tested using either a D.I.Y. kit or the services of a mail order soil-testing laboratory.
In mild weather lily bulbs may be planted. Choose slightly shaded positions where bulbs will not be disturbed. On heavy soils plant only after improving the drainage and place the bulbs on a deep layer of gritty sand.
Protect less hardy plants from severe weather, by covering with suitable materials or moving any plants in containers to sheltered locations. Protect pots and containers from frost damage with old carpets etc. Ensure containers are on pot feet for best drainage.
In mild areas some gardeners prune winter flowering heathers as flowers fade, however from experience it may be best to leave this until new shoots appear in spring.
Take root cuttings of suitable plants e.g. Phlox, Primulas Pulsatillas Acanthus mollis etc.
Prune and tidy winter flowering Jasmine in milder areas after it has finished flowering.
Tidy up all borders, pruning where necessary, lightly fork over beds without disturbing any roots or emerging shoots.
Remove fallen leaves and debris etc. from alpines and other choice plants to prevent decay and lessen chances of attack from slugs.
Clear dead tops of non‑shrubby plants from borders. Fork over surface of soil between plants and bury weeds. Continue digging heavy soils to be weathered by frost. Leave the soil in sods rather than a fine tilth, the frosts will break down the soil for you. Never turn this soil over in spring, simply use a three pronged cultivator or the tines of a fork pushed backwards and forwards.
Lightly cultivate around bulbs if possible to keep weed seedlings at bay and aerate the soil after last year’s wet autumn, but without damaging emerging shoots or surrounding plants.
Prevent slug damage to young emerging shoots by applying slug pellets etc. especially during mild wet weather on Carnations, Pinks and Delphiniums. Use a slug killer as a prevention rather than waiting for signs of damage.
Plant out hardy pot grown bulbs that have finished flowering, weather permitting. Otherwise keep in a cold frame until conditions improve, feed bulbs regularly to build them up to flower in subsequent seasons.
Plant deciduous hedges in strips of well-prepared ground. Remember small young plants always establish better than larger specimens. Carefully align young plants to obtain the thickest hedge and trim regularly even as young plants, this produces more rapid and thicker growth.
Pick over plants such as Pansies, Bellis and Polyanthus removing any yellowing leaves. Watch out for greenfly during mild spells of weather, spray if seen.
Scatter a general fertilizer around summer bulbs such as Fritillaria imperialis and Lilies. These and Lily of the Valley may also be top-dressed with a leaf-mould/grit mix.
Check protection on tender bulbs such as Agapanthus, Eremurus and Nerine, January can be a cold month.
Plant plump fleshy lily bulbs as soon as they arrive in the garden centres. Either pot or plant direct into the garden. Lilies are best planted on a well-drained site with extra grit for drainage. Leaf-mould can be used to aid moisture retention and provide food. Watch out for slugs.
Protect the roots of pot grown subjects such as Camellias and Bays from frost. Wrap pots with insulation, and keep in a most sheltered place during inclement weather. This is especially important where plants are grown in thin walled plastic pots, affording little frost protection. Camellias will die if their roots are frozen.
Plant named divisions of pampas grass, divide overcrowded clumps and feed with high potash feed existing plants.
Rejuvenate old hedges such as privet and hawthorn by pruning hard, on some hedges this is best done over several years, pruning one side first then the other.
Check around Primulas in the garden. Lightly stir the soil but on no account disturb resting buds or damage roots.
Protect flowers such as crocus and Polyanthus from birds with wreath wire (never cotton).
Helleborus niger will be well into flowering now so remove any old flower stems and plants will benefit from a slow release feed and a mulch of well rotted leaf mould which must be kept away from the neck of the plant. Continue to feed until late summer. The orientalis or lentern rose group of hellebores can have the previous years foliage removed as the new flower stems elongate.
The cooler December means the Helleborus ‘Ashwood Garden Hybrids’ are slightly later coming in to bloom and the wild bees are looking for food!
January and February are the ideal month’s to juggle around deciduous shrubs and other plants in the garden that may be in the wrong place. Plants that are too close together can be separated and where plants are too close to the edge of the lawn the width of the border can be slightly increased by digging in the turf and creating a wider border. I would not consider transplanting evergreens until late March at the earliest.
This is a good time of the year to remove any old leaves and rubbish from the base of hedges, together with any Ivy.
Prevent areas of ponds and pools from freezing by inserting an old tennis ball in ice free water and regularly gently pressing down to release dangerous gases building up under the ice. Alternatively use an electric pool heater ‑ preferably operated on 24 volts via a transformer. Alternatively place a saucepan of hot water on the ice and keep topping up with hot water. (Keep a piece of string attached to the handle in case it sinks when topping up!)
Following periods of heavy snow attempt to remove excess snow from evergreens and conifers, tying in any loose branches for maximum support.
During adverse weather conditions put out suitable quality wild bird food and ensure a regular supply of fresh water is constantly available. Sunflower seeds and specialist winter seed mixes are much more valuable than peanuts. Bread is lethal and should be avoided.
Check round the garden for pests such as greenfly over wintering, spray to control or where possible remove unwanted host plants such as groundsel.
Sweep lawns with besom, when dry, to remove debris and worm casts. Be prepared to lightly top your grass during mild periods of weather if ground conditions permit. Lightweight hover and rotary mowers are good at this time of the year for lightly topping the grass without compacting the soil.
Repair edges to lawns by reversing damaged edges. Where necessary carry out any turf laying and repairs when weather is open and ground conditions are suitable. If not previously carried out, the lawn may be top-dressed with a mixture of loam, peat and sand.
My lawn was mown in late December 2019 with the battery powered 56 volt Ego rotary lawn mower to clear light debris and to top the grass to a uniform height around 35-40mm.
Check over the lawn mower and other powered equipment, adjusting and servicing where possible. Alternatively have your tools professionally serviced before you need them and everyone else requires service
Watch out for problem spots at this time of the year such as waterlogged or wet areas. Note any areas of excess moss. Plan treatment such as spiking or install drains. Continue to keep the lawn clear of debris and be prepared to lightly top the grass during really mild weather, but keep off if too wet.
Net fruit trees and bushes to help prevent bud damage caused by birds however be prepared to remove nets at the threat of heavy wet snow.
Prune out previous year’s fruited wood on blackcurrants i.e. darker stems and examine for swollen buds indicating an attack of big bud mite. Remove and burn any infected branches. Newly planted blackcurrants should be cut down to within 3 inches (75 mm) of the ground. Take cuttings of blackcurrants by using 7‑10 inch (175‑250mm) sections as hardwood cuttings and burying completely upright in trenches.
Prune autumn fruiting raspberries. Tie in raspberry canes to training wires (summer and autumn fruiting varieties). Check posts and wires and control any weeds amongst the canes.
Prune gooseberries if not already done ‑ moderate thinning is all that is required. Protect bushes from birds with netting, remove if snow is forecast to prevent damage.
Feed soft fruit bushes with sulphate of potash at the rate of 30 gram sq m (1oz. to the square yard) annually, and 60 gram sq m (2 oz to the square yard) of Superphosphate every 2-3 years. Alternatively use a compound fertilizer such as Vitax Q4. Those gardening on lighter sandy soils can increase the rate by up to 50%
Cloches or plastic covers should be placed over any early varieties of strawberries.
Spray fruit trees with winter wash (often based on citrus extract rather than the illegal Tar oil) on dormant trees. Check tree ties and supports of trained trees. Continue pruning apple and pear trees when dry to prevent canker. Examine apple trees for canker wounds, cut out and paint over. Check and renew grease bands on trees to prevent the adult females of several moth species crawling up the trunks to lay their eggs.
Prune Damsons, Medlars Quinces and Mulberries. In most cases only light pruning is required, keeping especially damsons open in the crown to ripen wood and fruit All young trees require careful formative training more than pruning.
Plant new fruit trees and bushes when conditions allow and order replacements for old or dead plants but try to avoid planting in the same spots as previous trees. Plant Morello cherries on north facing walls in well prepared planting pits. Bitter or sour cherries are best grown facing north while sweet cherries prefer more sun on a south or west aspect.
If not already completed, prune grape vines during dormant period before sap rises, except when stems are frosted, by reducing laterals to one or two buds. Grape vines may also be planted at this time of year in well prepared planting holes enriched with plenty of organic matter after thorough double digging.
Carry out routine winter pruning of fruit trees, especially apples and pears, removing larger branches with pruning saw and treating wounds with fungicidal timber sealants. Also cut off any sections showing signs of mildew. Aim to keep the centre of all fruiting trees open to admit light and air. Do not prune stone fruits at this time of the year.
Contrary to belief older figs benefit from having some of the oldest stems removed in order to promote vigorous sucker like growths that will mature and produce fruit.
Check all fruit tree ties and stakes, also any supporting posts for soft fruit such as Raspberries. Check all supports on wall fruit especially vine eyes, repair as necessary.
Apply residual weed killers to areas of established fruit, but do not use where suckering subjects such as raspberries are being grown.
Check all fruit in store discarding diseased and deteriorating stock.
Protect crops against birds and cold weather.
Finish winter digging, leaving the surface rough. Do not dig in manure where root crops are to be grown this year.
Outdoor rhubarb can be forced by covering crowns with large lightproof box or dustbin. Plant new rhubarb crowns, covering each planting station with strawy manure for winter protection. Divide old crowded crowns, lifting carefully and discarding the oldest central crown, replant the others 1m (40”) apart after improving the ground with organic matter and thoroughly digging over 60cm (24”) deep.
Sow leeks and onions under protection for transplanting later, if not already done.
Place cloches or new one of the fabrics over light soils in sheltered spots in anticipation of early sowings.
Make first sowings of cauliflower, cabbage and lettuce if you have heated glasshouse, for harvest late May to early July.
Cover sea kale crowns in a similar manner to rhubarb to encourage early shoots.
Protect any autumn sowings of peas and beans with cloches etc. and examine/protect from slug damage.
Weed Asparagus beds if necessary and mulch.
Purchase seed potatoes, unpack and set up the egg size tubers on end immediately in boxes or egg trays in frost free, well lit place, to produce plenty of sturdy sprouts for planting time. Choose cultivars carefully for cropping season and resistance to pests and diseases. For example Pentland Piper is eelworm resistant, Pentland Dell and Pentland Ivory are less susceptible to keel slug attack while Maris Peer resists scab and eelworm. For chitting the temperature should be 5-7°C (41-45°F), some light is necessary, but restrict the humidity and keep the air circulating. This should produce sturdy sprouts that will provide a longer growing season and a heavier yield. Watch out for greenfly on tubers, spray with an insecticide at first signs.
Sow early frame varieties of carrots in heated cold frames or those built on a hot-bed system.
Remove any dead diseased and yellow leaves from brassicas and protect the plants from hungry pigeons. Clear brassica stalks as crop finishes to prevent carry over of cabbage aphid, burning old stems.
Towards the end of the month sow peas in sheltered mild areas, south of the Midlands on well-drained soils.
Lift, divide and replant sage and thyme. Plant new herb gardens, allowing sufficient space for plants to spread.
Apply wood ash to the onion bed and lightly fork over when dry.
Start preparing ground for runner beans by thoroughly double digging area and adding compost or manure. Sow broad beans in sheltered areas and on well-drained soils.
Lift a few root vegetables such as carrot, parsnip, salsify and artichokes in case of severe frost, ideally packing in boxes or piles of damp sand to prevent shrivelling, and check any others, such as potatoes and onions in store discarding any deteriorating material.
Beetroot still in good condition but are taking space that should be dug as soon as possible
Apply ground limestone or chalk to areas where brassicas are to be planted later if your soil is neutral or acidic.
Cover areas with sheeting to warm the soil ready for early sowings. The use of raised beds and covers makes for an early start especially on sandy soils.
Prepare pea trenches, digging out top 60cm (24”) to allow the forking over of the base before incorporating 7.5cm (3”) layer of manure, finally replace the topsoil firmly adding 60 grams sq m (2 oz sq yd) of bone meal and 30 grams sq m (1oz sq yd) of sulphate of potash. (Note peas and beans require little nitrogen as they produce their own)
Watch out for slugs in the vegetable garden, use pellets or organic alternative
Many houseplants will have been given as Christmas presents and it is important to ensure plants are kept in suitable positions, remember poinsettias need 18-20°c (65-70°f) to be happy while such temperatures would be far too high for Polyanthus, Cyclamen, Azaleas and forced bulbs, these are all better in much cooler conditions around 7-12C (45-55F) do not overfeed or overwater and allow plants to settle down. Planted bowls make be disassembled and plants potted individually in as small a pot as practical. Any potted bowls left planted must be watered carefully as few have sufficient drainage if any at all.
Indoor azaleas thrive on regular soakings, and can be plunged into bowls or buckets of lime free water up to the lower branches until the bubbles stop emerging, plants can be left to drain before being placed in a cool well lit position.
Sow onion seeds under glass or in a propagator, treat with a fungicide and grow on cool. Prick out before the loop of foliage straightens out, into trays or individual cells. Grow on in a temperature of 8-12°C (45-55°C) in maximum light.
Where possible give all greenhouses a thorough cleaning using Armillatox, Jeyes Fluid or Garden Disinfectant to remove algae and pests/diseases, which may be over-wintering. Check and prepare propagators for use. Make sure all pots and seed trays are thoroughly cleaned.
Carefully plan the use of heated and unheated greenhouses for the next few months, taking into account possible national weather trends and effects of the local microclimate. Prior to use of greenhouses, it is advisable to install secondary glazing in the form of bubble insulation after thoroughly checking the greenhouse for leaks due to glass slippage etc. Run heating systems checking efficiency of heater units, temperature control, thermostats etc.
Do not rush to sow seeds when it may be difficult to maintain high temperatures e.g. for newly pricked out geranium seedlings requiring a temperature of 68 F. Take opportunity to sow a few seeds of cabbage, cauliflower and lettuce to provide first cut of new seasons greens in June. These will not need much heat to germinate and little or none is the requirement once they are up. Sow leeks and onions under protection for transplanting later, if not already done, and prick out/pot up just before the seedling finally uncoils.
Buy in or make up seed sowing compost and store in a warm environment ready for use. Never use cold or frozen compost. Remember compost only has a limited shelf life - try to use it up within 3-4 months of purchase.
Towards the end of the month pot up a few tubers of early potatoes. Use 25cm (10”) pots and good garden soil, Use 7.5cm (3”) layer of soil and then place tubers upright and cover with 5cm (2”) of soil and keep topping up as shoots emerge, tubers should be ready to harvest ten weeks later.
Take root cuttings of Anchusa border Phlox, Anemone hupinensis and Verbascums.
Pot on autumn sown sweet peas into 7cm (3”) pots individually and keep cool. Some form of twiggy support may be necessary. Grow on in cold frame or cool greenhouse.
Bring in potted bulbs to maintain succession of flowers later on, stake and tie daffodils etc. as unobtrusively as possible. Old flowering bulbs may be kept in the glasshouse until conditions are suitable to plant outside. Lily bulbs may now be potted up to provide flowering plants in late spring. Gladii also make good pot subjects flowering in late spring and early summer if potted this month, grow in a similar manner to lilies.
Careful attention should be paid to ventilation especially during damp weather. Remember, where gas or paraffin heaters are being used it is essential to leave a ventilator slightly open to avoid toxic fumes.
Botrytis on my variegated Geranium collection needs more air and leave the fan running on the greenhouse heater, water only if desperately needed.
Where pests and diseases are a problem it is often best to use smokes at this time of year rather than sprays. Sometimes of course, sprays are the only method available in which case pick a bright sunny day, and apply the spray in the morning, so allowing the foliage to dry before the evening, but keeping direct sun off soft foliage.
Pot on any Geranium and Pelargonium cuttings as growth commences ‑ watch out for greenfly, control at first signs. Pinch out growing points to encourage busy plants unless cuttings are need, which can be removed early next month.
Prune and re-pot back into same size pot, old Fuchsia plants prior to restarting them into growth. Over-wintered cuttings may be potted. Standard fuchsias should be carefully examined thinned and pruned to encourage formation of a dense new flowering head in the new season. Treat all posts of fuchsia with Provado to control the larvae of vine weevil; an added bonus will be the control of all foliage and soil pests for six months.
Check over early and late flowering Chrysanthemum stools removing any decayed leaves. Do not over-water nor keep in too warm an environment. Towards the end of the month they will benefit from being placed onto a heated bench to encourage strong soft new growth for cuttings in Feb. or March, date depending on cultivar, those being grown for exhibition may well have already been propagated.
Feed Cinerarias weekly with a flowering houseplant fertilizer or weak tomato fertilizer applied to the soil. Calceolarias should be fed similarly every 14 days. Check on over-wintered tubers of Gloxinias and Begonias, discarding any rotting tubers, or cutting out any minor infections and treating the clean cuts with a suitable fungicide.
Keep Primulas and primroses in cool conditions e.g. 6-8°C (40‑45°F). Water sparingly and keep in good light. Schizanthus, Cinerarias and Primulas may be treated likewise whilst Calceolarias require slightly warmer conditions.
During periods of extreme cold weather plants in the glasshouse should be kept drier. However, during sunny periods rapid drying of compost occurs often causing plants to wilt, but do not be fooled by the large soft leaves of plants such as Calceolaria and Cineraria, as these can easily wilt when the plant roots are still moist. Where possible, watering should be carried out in the mornings.
Towards the end of the month, where conditions permit, geraniums, Begonias Antirrhinums, and sweet peas may be sown.
Clean the leaves of houseplants. Leaf shines can be used on shiny leaved subjects but if in doubt simply use a damp clothe in one hand supporting the leaf with the other hand.
Cut back Plumbago and Passiflora to 1 or 2 buds of old wood.
Take cuttings of Coleus, Heliotrope and geraniums by using short, softwood material inserted in a propagator.
Plants received for Christmas are often relegated to the greenhouse due to poor appearance in January. Remember Azaleas require regular immersion of pot in tepid water whilst Cyclamen will not tolerate waterlogged crowns and should be watered from the base. Inspect all potted plants in house and glasshouse removing any damaged/dying foliage and faded flowers and keep leaves free from dust using proprietary leaf shines only where recommended by manufacturers.
Keep the glass clean inside and out during these short days. Plants should be kept in good light to prevent leggy, elongated plants developing.
Sow seed of fibrous rooted begonias for maximum flowering period. Along with Gloxinias they need 18c (65°f) to germinate. Cannas hibiscus and hippeastrum can be sown given a temperature of 21°c (70°F), the former need soaking in warm water for 24 hours prior to sowing. Tomatoes for a heated greenhouse planting in March may be sown in January using a heated house cultivar.
Prune indoor vines, cutting back to main rods.
Bring rhubarb crowns into the greenhouse for forcing to harvest in six weeks time. Place roots on soil base and cover with material to ensure complete darkness.
The use of greenhouse smokes is preferable to that of sprays at this time of the year for pest and disease control.
Sow seeds of alpines such as Andosace, allow pots to freeze out of doors, and then bring into a temperature of 70°F
Bring a pot-grown Camellia into a cool greenhouse or a cool room, and enjoy the beauty of the blooms
Botrytis is a serious disease that often attacks plants in greenhouses at this time of the year, extra care is needed when watering to keep the foliage dry and not to overwater. Circulating air helps to prevent the disease and limits its spread. Carefully pick off affected leaves without leaving snags or wounds that can lead to more infection. Fungicidal sprays maybe used with care. Only water plants in sunny weather and during the early part of the day. The amount will depend on the proposed weather over the next few days.
Pot up a few roots of lily of the valley, use the plumpest shoots and place in 12cm (5”) half pot of compost, keep shade in greenhouse with temperature of 16°C (60°F)
Check the greenhouse for loose or slipped glass, a small hole can loose a lot of heat and burn a hole in your pocket.
If the weather is dry and conditions not freezing, treat fences and sheds with a timber preservative. Wash stakes and canes if necessary and where appropriate apply timber preservatives (non‑toxic) to below ground sections.
Wash all used plant pots containers and canes in a disinfectant such as Armillatox Jeyes Fluid or Garden Disinfectant. Clean garden tools using oils etc. as required, and do not forget the lawn mower maintenance.
Treat paths and patios covered in algae with a proprietary path cleaner and during periods of inclement weather use agricultural salt or other de‑icing products such as Doorstep De‑icer.
Make repairs to fences, paths and other paved areas. Provided it is not frosty or likely to be in the next few days, your concrete will set properly. It may be more pleasant working on these jobs in warmer weather but there will be more demands on your time.
What is the state of the garden shed roof does it need re‑felting and sealing? Is everything in its right and proper place, neat and tidy and secure?
Clean out existing bird boxes (do not use harsh cleaning agents or timber preservatives). Put up new boxes in suitable locations. Continue to feed birds, using a wide selection of feeds and provide fresh drinking water.
Plants worth looking at in January
Helleborus corsicus, H. foetidus, H. niger, H. orientalis and garden hybrids
Iris unguicularis (stylosa)
Pulmonaria angustifolia, P. rubra, P. saccharata
Chimonanthus praecox ‘Grandiflorus 2.4-3m (8-10ft) spicy deep yellow flowers with red centres C. p. ‘Luteus has pure yellow flowers
Cornus alba (all the dogwoods)
Hamamelis mollis cultivars
Viburnum fragrans, V. bonantenses ‘Dawn’
Erica carnea and var., E. darlyensis, E. lusitanica
Mahonia bealei 1.8 –2.4m (6-8ft) lemon yellow flowers M. ‘Charity’ 2.4-3m (8-10ft) fragrant deep yellow flowers M. lomarifolia 2.4-3m (8-10ft) deep yellow erect spires of flowers M. japonica
Clematis calycina, C. cirrhosa
Acer davidii, A. pensylvanicum, A. capillipes
Betula papyrifera, B. utilis
Prunus subhirtella autumnalis rosea
Salix matsudana ‘Tortuosa’
Begonia fuchsiodes, B. manicata, B.socstrana (small flowered winter hybrids)
Primula kewensis, P. malacoides
Vegetables from the garden
Jerusalem artichokes, broccoli, sprouts, endive, kale, leeks, lettuce, parsnips, savoy cabbage, turnips
Fruit in store
Apples: Adams Pearmain, Barnack Beauty, Blenheim Orange, Bramley Seedling Cornish Gillyflower, Cox’s Orange Pippin, Lanes Prince Albert, Laxton’s Pearmain, Lord Hindlip, Newton Wonder,
The information given in this Fact Sheet is provided in good faith. It is however of necessity general information and advice on the topic. Howard Drury will not be under any liability in respect of the provision of such advice and information and you are strongly advised to seek independent advice on any particular gardening problems or queries you may have, preferably from experts who can (when appropriate) inspect the problem before providing advice.