Gardening in January – 3. Planting

Gardening in January – 3. Planting

Gardening in January – Planting in January

We already talked about other work to do in January and found out how plants survive frost and snow – but this article will focus on planting and plant care in January.

Even Though it’s cold outside and still winter, you want to prepare plants for the year. Plant care in January is critical. It can decide whether your plants survive the cold temperature or die freezing.

You may need to order seeds in January that you want to be planting in March. It can take some weeks to deliver the Seeds, and you want to be well prepared and ready for the new season.

House and conservatory plantshouse plants

Protection and light

Plants are vulnerable to draughts and overwet compost at this time of year. Keep tender plants at or above their minimum temperature. Remove plants from cold windowsills at night, but keep them near a window during the day so they get as much light as possible. Artificial light is beneficial, but keep foliage away from direct heat and avoid the hot, dry air of centrally heated houses.

When the compost is consistently too wet, the roots will rot. Tip the damp plant out of its pot if you don’t want the plant to rot and wrap its rootball in several layers of newspaper for a day or two. Change the paper when it is saturated. When the compost has dried out slightly, replace the plant in its pot.

Try to provide a minimum temperature of 7°C (45°F) in the conservatory. Insulation can help to reduce heating costs.

Feeding

Only feed house plants if they are growing strongly or are in flower.

House plants – overwatering.

Most house plants will collapse if overwatered. You may be able to save an affected plant by wrapping the rootball in an absorbent paper for a day or two. Cover the roots and change the paper if it gets too saturated.

Flowering plants

Keep flowering plants purchased at Christmas in a cool room and deadhead azaleas and primulas regularly to extend their flowering period. Modern poinsettias last a long time in flowers after flowering. Cut back their stems to 15 cm (6 in) from the bases. Keep the compost almost dry until May.

Bring pots of polyanthus, which you potted up in the summer indoors, and keep them in a cool room at a temperature of no more than 10 °C (50°F) until they are about to flower.

Sow seeds of gloxinias and streptocarpus in a propagator over the next two months so that they will make plants large enough for display by late summer.

Indoor bulbs and corms

Increase watering of hippeastrum’s planted up last month and keep them warm and moist.

Keep cyclamen and lachenalias in a cool room; deadhead regularly to extend the flowering period.

Bring pots of forced bulbs still in the light, cool positions into the warmth when they are ready to flower. Keep the compost moist and deadhead when blooms fade. Feed with half-strength tomato feed if you want to keep them to plant out.

Bromeliads

Keep these in bright light at a minimum winter temperature of 15°C (60°F). Bromeliads such as the urn plant (Aechmea fasciata) and billbergia will survive at 7°C (45°F) but will become dormant.

Mist air plants once or twice a week, holding a hand-held mister about 30 cm (12 in) away from the plant. Mist lightly; do not make them too wet.

Cacti and other succulents

Rest these overwinter at a temperature between 7 and 10°C (45 and 50°F). See that the plants get plenty of light but keep them dry or barely moist.

Orchids

Water sparingly unless they are growing actively but don’t let the compost dry out completely. Keep any growing plants at their optimum growing temperature and dormant plants just above their minimum. Some popular orchids can be overwintered successfully at a temperature as low as 10°C (50°F).

Rhododendrons and azaleas

Gardening in January - Planting in January - Rhododendron

Protecting from the weather

The flower buds of many rhododendrons (mostly dwarf varieties) and evergreen azaleas can be damaged by cold weather and harsh winds. Erect a netting screen on the north and east sides of the plants to reduce severe weather damage. In freezing weather, cover the plants with woven fiber frost-protection fleece or a similar lightweight material. Remove it during mild periods. If flower buds become damaged, pinch them out to prevent the development and spread of fungal diseases.

Controlling coral spot

This is an excellent month to look for traces of the fungus disease, coral spot, particularly weak or dead branches. Although this fungal disease does not usually kill plants, it can spread from slow growth to live growth under certain conditions. Cut any trees and shrubs that are affected back to healthy wood and then dispose of the prunings. Don’t put them on the compost heap.

Removing suckers

A particular problem with rhododendrons is the development of suckers from the base of grafted plants. Cut back all suckers at their point of origin as soon as you notice them.

Rock Plants

Maintaining the beds

Remove any dead leaves and work over the soil between plants with a hand fork.

Sow seeds in January

Sow remaining seeds that need frost to germinate.

Ordering new plants

This is an excellent month to study plant catalogs and order plants for the spring. Remember when ordering that you will need up to 12 slow-growing rock plants to fill 1 m (10 sq ft), but only four or five of the more rigorous kinds.

Trees, Shrubs, and Hedges

Pruning in January

Check for broken, diseased, or dead branches on established trees and shrubs. Using a pair of secateurs or a pruning saw, carefully remove affected branches, leaving a clean cut that will heal quickly. Also, remove any crossing or rubbing branches that are causing an obstruction. Avoid pruning members of the Prunus family (ornamental cherries and plums). These should only be pruned in the summer as they are prone to attack from the silver leaf.

Planting in January

Provided the soil is not frozen or waterlogged. Container-grown and bare-root deciduous hardy shrubs and trees can be planted. Dig the soil well and add liberal amounts of organic material, such as well-rotted manure, garden compost, or peat substitute, to ensure good root development. According to the manufacturer’s instructions, add bonemeal gives the plant all the nutrients it needs when growth starts in the spring.

When the weather is unsuitable for planting, dig a shallow trench in a sheltered spot and heel in any plants that arrive from the nursery. Alternatively, store new plants in an unheated, frost-free area and place moist material around bare-root plants’ roots, planting out when the weather improves.

Ensure that stakes are appropriately inserted, are of a suitable size, and that the tree or shrub is correctly tied to the stake.

Hedges

Bare-root plants for hedges may arrive when the soil is frozen or waterlogged. If they have been packed in bundles, open them out to allow air to circulate and prevent rotting. Cover roots with straw, hay, or similar material and store them in an open, rodent-free place. Keep just moist to avoid dehydration.

Stand container-grown plants in a sheltered corner, but not under protection. Usually, these do not require watering but keep a careful watch on evergreens if planting is delayed for long. Plant out once the soil is workable. The establishment and successful development of hedges depend on well-prepared soil.

If you did not plant any hedges yet and want to get a few ideas, you definitely should check out the 10 Topiary & Hedging Ideas with Pictures.

Hardwood cuttings

Take hardwood cuttings and insert them in a prepared trench if the weather is mild.

Climbers and wall plants

Supports for climbers

Check on Trellis, Pergolas, Arches, and all other structures supporting climbers, and carry out any needed repairs. If necessary, untie the plants and remove them from their supports – a task which is much easier to do while the plants are dormant.

Renewing plant ties

Before plants start growing actively, check on the ties that secure them to their supports. Replace any ties that have rotted and add extra ties if required – a large climber in full leaf can be very heavy.

Ties and tying

It is important to tie climbing plants correctly to supports using the right materials, as otherwise they may be severely damaged by constriction or wind. Use ties made from non-preservative-treated twine or any product that will stretch or rot within a year. Do not use ties made from wire, plastic string, or bailer twine, as these will chafe and damage the plant as it rocks in the wind. The figure-of-eight is one of the best knots to secure climbers and wall shrubs to canes, wires, or trellis. To stop the tie and plant slipping sideways, pass the twine twice around the cane, wire, or bar of the trellis, then cross it over, passing it around the front of the plant. Secure it with a reef knot.

Pruning in January

If you have climbers, such as Virginia creeper (Parthenocissus quinquefolia), ivy (Hedera), and climbing hydrangea (Hydrangea petiolaris), growing in the house, cut them back by at least 45 cm (18 in) from all windows and door frames. Then the plants can regrow without obscuring these.

Hardwood cuttings

If the weather permits, take hardwood cuttings of hardy climbers now to save time in the spring.

Fan training

A few ornamental wall shrubs, pyracantha, and the Japanese apricot (Prunus mume) are good examples, respond best to being trained in a fan. This ensures that the branches are well spaced out and get an even amount of light and air. The shape of a fan is established during the first few years of the plant’s life. Select the branches to form the fan and tie them on to the canes. Prune out any unwanted shoots flush with the stem.

Stretch horizontal wires along a wall at 30 cm (12 in) intervals. Tie bamboo canes to the wires in the desired fan shape, then tie suitable branches to the canes. The branches’ tips should be about 30-45 cm (12-18 in) apart.

Container gardening

Moving containers under Cover

January often brings the first hard frosts of winter, and plants in pots and baskets are especially vulnerable. Move them to a more protected area or greenhouse if possible until milder weather returns.

Avoiding snow damage If heavy snowfalls build up on specimen conifers, there is a risk that some branches may get pulled out of position or break. To prevent this happening, either regularly shake off loose snow or tie loops of soft garden twine down the plant’s length to hold the branches in place. Large evergreen shrubs such as Mexican orange blossom (Choisya ternata) are also vulnerable to snow damage. The weight of the snow causes the branches to tear and fall outwards, leaving a hollow center. Support with a criss-cross of twine running through the middle of the plant.

Planting trees and shrubs in January

If the weather is suitable, you can continue to plant deciduous shrubs and trees in containers. Once planted, move to a sheltered spot to avoid wind rock and desiccation.

Tidying winter containers

Pick off fading flowers and foliage and trim back any frost-damaged shoots. Replace any dead plants and check the compost is not too dry.

Carnations and pinks

Gardening in January - Planting in January - Carnation

Improving soil condition

Test the soil’s pH with a kit or meter—carnations like a pH of at least 6.5. Garden lime can be used to increase the pH; peat or sulfur to decrease it. Carnations also dislike waterlogged conditions, so if weather permits, dig over any poorly drained sites, incorporating grit and well-rotted manure or garden compost.

Planning ahead

Order plants and seeds for planting in spring. Bear in mind the impact that silver-grey dianthus foliage has when combined with other plants, and plan future plant associations into your garden design.

Sow seeds of annual carnations. Space the seeds 5 mm (¼ in) apart in trays and cover them with a fine layer of compost. Cover with glass or plastic sheeting and keep them at a constant temperature of 13-15°C (55-60°F).

Maintaining healthy conditions

Ensure that the temperature does not drop below 7°C (45°F) for perpetual-flowering carnations in the greenhouse, and make sure there is some ventilation at all times. Water and feed sparingly, cutting blooms and disbudding flower stems as necessary.

Controlling pests and diseases

Watch out for aphids and carnation rust and, if necessary, use dust in preference to sprays in winter so that the atmosphere in the greenhouse does not become too humid.

Increasing stock under the glass

Continue to propagate perpetual-flowering carnations by cutting. Pot up rooted cuttings into 5 cm (2 in) pots. Start sowing seeds.

Ordering new plants in January

Order new plants now from reputable nurseries for spring delivery.

Dahlias

Gardening in January - Planting in January - Dahlia

Inspection of tubers

Examine stored tubers every few weeks during the winter and, if they are shriveling, plunge them in a bucket of tepid water for a night (under Cover if it is a cold night) to plump them up again. Dry the tubers thoroughly and replace them in their boxes.

If stored tubers show any signs of rotting, such as dampness on the stems, cut away any portions of the tubers damaged and treat the cuts with sulfur dust. Ensure the labels remain tightly attached to the tubers.

Ground preparation

Dahlias prefer a position in full sun and do not grow as well if they are planted in a mixed border of herbaceous plants as they do in a bed on their own. Suppose you want to grow top-quality blooms, whether for cutting, for exhibitions, or for color in the garden, try to find a place for them where they will not have to compete with other plants.

Start to dig the dahlia bed as early in the year as possible to permit frost to act on the soil. Dahlias will thrive in any soil that is neither too acid nor too alkaline, but they are gross feeders and require considerable amounts of moisture during the year. To help provide this, incorporate as much composter or well-rotted manure as possible.

Lilies

It’s an excellent time to sow seeds in January. Sow lily seeds not more than 1 cm (½ in) deep in pots or boxes.

The seeds of lilies, such as Lilium candidum and L. lancifolium (syn. L. tigrinum), germinate and appear above ground within a month of sowing, usually as little green loops somewhat similar to onion seedlings. Others, such as L. martagon, start by producing a tiny bulb. Nothing further emerges until possibly a year after sowing, when a small lance-shaped leaf appears on the surface.

Forcing bulbs

Bring pots of lilies inside for forcing. Keep them at a temperature of 7-10°C (45-50°F) until growth is well started, then raise it gradually to 15-20°C (60-70°F). The lilies should bloom 12 to 13 weeks later – in time for Easter.

Lift any surplus healthy lilies from the garden for gentle forcing under glass. Use an excellent soil-based compost such as John Innes No. 1 with added peat (or peat substitute) and grit to keep the texture open. An added handful of leaf mold is beneficial.

Planting Lilies in January

Lilies can be planted at any time until the end of March, provided both soil and weather allow. Otherwise, temporarily pot up bulbs to keep them in good condition until the weather improves.

Pelargoniums

Taking cuttings

Pelargoniums are never dormant, so if you can provide warm compost using a propagator (without the lid) or a soil-warming cable, cuttings can be taken in any month of the year. Any good seed and cutting compost will be suitable, and the cutting should be well-rooted in about three weeks, depending on how warm the compost is and how good the light conditions are. Do not let the compost dry out and never cover the plants. The cuttings like being dry and rot if they are kept in humid conditions, so keep them in a light, airy place.

  • Choose a healthy shoot and cut it away from the plant above a node (leaf joint). The cutting does not need to be very long.- about 8 cm (3 in) is ideal. You can take several cuttings from one plant.
  • Trim the cutting to just below a node. Break off any side shoots where they join the main stem and remove all but a few leaves. If you can, take cuttings from non-flowering shoots. If you can’t, remove any flower buds.
  • Dip the cutting a hormone rooting powder. This helps it to develop a good fibrous root system. Generally, pelargoniums will root without rooting powder, providing they are kept reasonably dry and are not overwatered.
  • Insert the cuttings into moist compost in holes about 2.5 cm (1 in) deep—firm the compost around them—water from below after one week and again a week later. When new leaves appear, the cuttings have rooted.
Potting on

Regal and zonal pelargoniums to be grown as large specimens, which were rooted as cuttings in the autumn, will need to be potted on to larger pots. Give them plenty of room to grow and remove all dead or damaged leaves. Turn the pots regularly and shape the plants by stopping.

Sow Seeds in January

Seeds of pelargoniums ideally need to be raised in a constant soil temperature of 20-24°C (70-75°F). Given these conditions, germination will take only a few days. If the soil temperature is not maintained, germination can be erratic, so do not give up on the seeds until several weeks have passed. Plant them about 5 mm (¼ in) deep and not let the compost either dry out or become waterlogged. Covering is not essential, but if you put the seeds in the dark, check every day to see if any germination as seedlings will rapidly become spindly if they are not given good light conditions.

Roses

Gardening in January - Planting in January - Rose

Caring for greenhouse roses

Roses that are being forced in pots in the greenhouse for early flowers and cuttings will benefit from a little heat during cold spells – aim to keep the greenhouse at 5°C (41°F). Close the ventilation at night, but open them on sunny days. Water to keep the soil moist, but do not soak.

Sweet peas

Topdressing seedlings

Prick over the top of the compost of plants sown in pots in October. Use a piece of stick or an old kitchen fork to aerate the compost. A light dressing of fresh compost acts as a tonic for the plants.

Sow Seeds in January

Seeds can be sown in slight heat, about 4°C (40°F), following the method outlined for autumn sowing. Many sweet pea growers consider planting this month preferable to sowing in the autumn, and it is undoubtedly more suitable for the compact types.

Dressing in lime or sulfur

The most suitable pH for sweet peas is around 6.5, which is very slightly acid. If your soil’s pH is below this, apply lime to increase alkalinity; if above, add sulfur to acidify the soil.

Know your sweet peas

For exhibition or cut flowers with long, straight stems, choose a Spencer type, grow the flowers up canes, and train them using the cordon system. For ordinary garden display, sweet peas grow well up with wigwams or other supports. You may find Multiflora varieties particularly pleasing grown like this for general garden decoration. There are various dwarf mixtures – some as low as 30 cm (1 ft) – suitable as an edging for a bed. Intermediate varieties that grow to about 90 cm (3 ft) are useful for a patio or confined space. The stems of these mixtures are not long, so they are less useful for cutting.

Chrysanthemums

Early-flowering (garden)

Overwintering

Examine the soil around outdoor-flowering varieties, which have been left to overwinter in sheltered, mild gardens. If the soil seems to be waterlogged, pierce the ground around each plant several times with a fork inserted to its full depth. Tread any ground loosened by frost to reform it around the roots.

Ventilate dormant clumps bedded in cold frames when it is not freezing or windy, but protect them from frost with sacks or matting. Water dormant clumps sparingly.

Soil preparation

Complete digging on heavy ground and work bulky organic matter into the top 15 cm (6 in) of soil—test for alkalinity. Chrysanthemums do best in soil with a pH of 6.5.

Late-flowering (greenhouse)

Controlling pests

Treat chrysanthemums under glass affected by aphids and leaf miners. Keep the maximum temperature in the greenhouse at 10°C.

Taking cuttings

Take cuttings of large exhibition varieties. Even if you don’t plan to take cuttings now, cut back any shoots longer than 8 cm (3 in). This will keep the plants in good condition for propagation, which you can then carry out during March and April.

Flowers of every late-flowering varieties will carry on well into this month in a cool, dry greenhouse. Take cuttings from these plants now, provided the shoots are strong and healthy.

Potting up

Towards the end of the month, pot up rooted cuttings of large exhibition varieties growing in the greenhouse into 9 cm (3½ in) pots.

Fruit

Gardening in January - Planting in January - Apple Tree

Spray fruit and bushes with a winter wash if pests were a problem last year. This should only be done if it is essential since it kills as many beneficial insects as it does pests.

Fruit trees and bushes can be planted if the soil conditions are suitable. If not, keep any container-grown plants in a frost-free place or heel them in.

Apply a general fertilizer, such as Growmore or blood, fish, and bone, to all fruit trees over 4.5 m (15 ft) high, following the manufacturer’s instructions. Applying now will allow ample time for the fertilizer to be dissolved and carried deep into the root systems. When the trees are growing in grass, use a fertilizer higher in nitrogen to compensate for the nitrogen that will be taken up by the grass.

Order Fruit trees for planting in January from a great shop. Great Examples are the Anna Apple Tree, Kieffer Pear Tree, or a Barbados Cherry Tree.

Inspect ties regularly during the winter and replace any that are tight or broken. Replace broken stakes only if the tree still needs support, as hammering in a new stake may damage the root system.

Apples and Pears

Continue pruning apples and pears except when the temperature is below freezing. If possible, shred the prunings and add the shreddings to the garden compost. This is a valuable raw material, and the shreddings will help to aerate your compost heap or bin.

Check all apples and pears you have stored over the winter and throw away any that have rotted before they spoil the sound fruit.

Peaches and nectarines

Feed all large fan-trained trees with a balanced fertilizer, such as Growmore or blood, fish, and bone; follow the manufacturer’s instructions. This will ensure that plenty of new shoots are formed.

Plums and cherries

Plums and other stone fruit should only be pruned during the growing season – not at this time of the year. This reduces the risk of infection by silver leaf fungus.

Cane fruits

Cut down newly planted canes of raspberries, blackberries, and any hybrids, such as loganberries and tayberries, to within 25-30 cm (10-12 in) of the ground. These stumps will produce shoots and, possibly, some fruit in the summer, but their main purpose is to sustain the new root systems.

Gooseberries and currants

Prune newly planted bushes of gooseberries and red and white currants by cutting back strong new shoots by half their length to form the main branches. Cut weak and misplaced shoots right out. On cordons, cut back leading shoots (those on the end of branches) by a third.

Cut back newly planted blackcurrant bushes to about 2.5 cm (1 in) after planting to encourage strong new shoots to come from below the ground. Although it is later than recommended for propagating, well-ripened shoots can still be used for taking cuttings.

Controlling vigor

If an established fruit tree is growing strongly but not fruiting, there are several possible ways to cure the problem. First, stop feeding the tree or switch from a high-nitrogen feed to a high-potash feed. Second, sow grass under the tree to take up some moisture since wet conditions encourage leafy growth. As a last resort, consider root pruning or bark ringing. Both these operations should be undertaken with caution because they could kill the tree if carried out incorrectly.

Annuals and biennials

Sowing slow-maturing bedding

Some half-hardy annuals and other bedding plants take a long time to flower from seed and must be sown in January or February if they are to bloom by early summer.

To be successful in this, you will need a heated propagator to germinate some of the seeds and a warm, light position to grow them on once they have pricked out.

Indoors, good light is critical to avoid plants becoming pale and drawn, but seedlings and young plants must be shaded from strong, direct sunlight.

Plants for early sowing include antirrhinums, African marigolds, Begonia semperflorens, gazanias, pelargoniums, and lobelias.

If you do not have the facilities for early germination, consider buying plants as ready-to-prick-out seedlings.

Damping-off

Seedlings started so early in the year are especially vulnerable to the fungal disease damping off, which causes seedlings and young plants to collapse at soil level.

Always clean used seed trays and pots thoroughly and sterilize them with garden disinfectant. Sow seeds thinly, avoid overwatering, and provide newly germinated seedlings with the best growing conditions you can.

Preparing new beds

Take advantage of any dry, mild weather periods to dig new flower beds ready for sowing and planting in spring. Leave the final raking and leveling until later, as weed seeds are bound to germinate and can be removed in spring.

Border perennials

Sowing slow-maturing bedding

Clear borders of weeds and debris keep them neat and prevent a build-up of garden pests and diseases. Some weeds will continue to grow and seed in mild winters, while others, such as creeping buttercup, are more easily seen when the ground is cleared. Avoid compacting the soil, particularly in wet winters, using short pieces of board to walk on. Fork over the soil when the job is finished.

Ground preparation

Dig any heavy clay soil that was left unturned in the autumn. Frosts will help break the soil down, creating a finer tilth. Dig in annual weeds, provided they are not seeding, but remove and destroy all perennial weeds’ roots.

Tidying borders

Tidy borders by removing overwintering weeds. You can remove dead stems and leaves from plants at the same time. This improves their appearance and reduces the risk of them sheltering pests and perpetuating diseases.

Frost and wind protection

Check the half-hardy perennials are protected against frost. Plantings from last autumn may also require some protection if the weather turns freezing. Use covers such as cloches, netting, plastic sheeting, newspaper, or even old woolens. Natural materials, such as dead bracken, straw, mulches, and conifer branches, can also be used. Ashes and cinders from fires must be weathered before use, as they may contain harmful chemicals. Remove all damp coverings as soon as the danger of frost passes since waterlogged materials may cause mildew. Provide permanent or temporary shelter against wind damage. Shrubs, trees, and hedges will help break the force of the wind.

Slightly tender Perennials, such as Lobelia cardinalis and osteospermums, need adequate winter protection in cold frames and greenhouses. Close and cover cold frames in frosty weather but open them in milder weather to prevent mildew.

Sow Seeds in January

Some border perennials will bloom in their first season if the seed is sown in warmth under glass over the next two months. Consult seed catalogs to see which varieties are likely to be successful (though all make better plants in their second year). Among the plants to try are alchemillas, capanulas, poppies, and violas.

Generally, seeds of hardy perennials should be sown in the appropriate compost and the pots and trays placed outdoors. Cover them with netting to protect them from birds and cats. Many seeds, such as hellebores and peonies, require a frost to trigger germination. When the first shoots appear, move the pots into a cold frame or unheated greenhouse. Leave sowing until February if this shelter is not available.

Bulbs, Corms, and Tubers

Summer-flowering bulbs

Order new summer-flowering bulbs and tubers, such as begonias, tigridias, and gladiolus corms, in good time from a reputable supplier. When they arrive, unpack and examine them. They should be firm and dry – discard any which have a soft base. Those sprouting will grow, but they may be slower to grow when planted out. Store the bulbs in shallow boxes or trays or return them to their bags after cutting air circulation holes. Keep in a dry, frost-proof place.

The theory that the largest gladiolus corms are best is quite erroneous. A young, plump, high-necked corm with a small root-base is preferable to a larger, flatter corm with a broad root-base.

Stored bulbs

Check bulbs, corms, and tubers that have been stored over winter and remove any that are soft or diseased.

Forced bulbs

Continue to bring bulbs in bowls and pots into the warmth and light for indoor flowering as they become ready. Apply a half-strength liquid feed, such as tomato or rose fertilizer, every three weeks. Deadhead the bulbs as the flowers fade and continue to water regularly.

These bulbs can be planted in the garden when flowering has finished, but do not plant them out until the weather and soil conditions are favorable.

Hippeastrums

Water the bulbs planted last month and keep them warm and moist as growth accelerates.

Fuchsias

Gardening in January - Planting in January - Fuchsia

Dormant plants

Check that plants packed away in peat for the winter and those remaining leafless and dormant in their pots do not become scorched.

Spray with tepid water any early growth on plants in the light to soften the wood. Do this sparingly as the inactive roots cannot cope with heavy watering.

Overwatering plants in green leaf
Ensure plants kept in green leaf get as much light as possible and are not becoming pale and leggy. Keep the greenhouse well ventilated even in cold weather, as condensation may encourage grey mold (botrytis).

Pruning in January

Towards the end of the month, watch for the first ‘pink eyes’ (embryo shoots) appearing on the stems. This indicates that the earliest plants are ready for pruning.

Vine weevil

Inspect plants in pots for vine weevil larvae. These white, crescent-shaped grubs lodge in the rootball and, if undetected, will eat away entire root systems. Gently knock each plant out of its pot and pick off any weevils by hand. Alternatively, dust the soil with a suitable pesticide or use a biological control.

Heathers

Preparing new beds

If you want to plant a bed of heathers, new planting areas can be prepared now during suitable weather. Mix copious amounts of sphagnum moss peat (or peat substitute), sand, pea grit, or perlite into heavy clay soils to improve the texture. Light sandy soils can also be enhanced by adding sphagnum moss peat (do not use sedge peat for this). For summer-flowering, heathers avoid spent mushroom compost as this contains lime and, if the pH of the soil is above 6.5, add flowers of sulfur to acidify the bed.

Dig in the peat and any other additives, mixing thoroughly with the original soil to a full spade’s depth. The addition of fertilizers is not necessary.

Autumn-planted heathers

Examine heathers planted last autumn, remove any weeds around them, and gently firm into place any plants which have been partially lifted by frost.

Herbs

Preparing the site

The dormant period of winter is the ideal time to prepare the ground for your herb garden. Many herbs like hot, dry conditions need to be planted in a sunny, south-facing position with some protection from north and east winds.

A sloping plot of ground facing south is ideal and provides a choice of locations that will suit different herbs.

Ordering seeds and plants in January

When you have decided on the herb garden’s shape and size, order seeds and plants’ readiness for the spring. While many herbs will grow true to type from seed, others will not and should be purchased as plants from a reputable herb nursery or garden center to ensure that you obtain the correct varieties.

Herbs to grow from seed

anise
sweet basil
borage (self-seeding biennial)
caraway (biennial)
German chamomile
chervil
chives (perennial)
coriander
dill
fennel (perennial)
lovage (perennial)
sweet/knotted marjoram
purslane
salad rocket

Herbs to buy as plants

lemon balm
bay
bergamot
garlic chives
curry plant
hyssop
lavender
pot marjoram
mints
rosemary
rue
sage
French sorel
southernwood
French tarragon

Gardening in January – Other Parts

Gardening in January – 1. Frost and Snow
Gardening in January – 1. Frost and Snow
Gardening in January is much more important than one might think. You want to make sure your Plants survive Frost and Snow. You have to do some Dirty Work to Prepare your Garden and start Planting in January. The First of the Three Parts will explain How Plants survive Frost and other Winter conditions.
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Gardening in January – 2. Garden Work
Gardening in January – 2. Garden Work
Is there some garden work to do in January? Can you work outdoors or should you only work indoors? There is a lot of garden work to do in January. Preparing your garden in winter is important. You need to order seeds, prepare beds for your plants and protect your plants from frost.
Read More