With the weather getting warmer and the risk of frost having passed, there is a lot that can be planted in both the flower and vegetable garden in April and May. 

Weather watch:

Although the risk of frost is diminishing, it is still a possibility as warm, cloudless days can be followed by cold nights. Keep an eye on the forecast and don’t be tempted to plant out tender plants until the first weeks in May.

Toughen up tender plants 

Seedlings nurtured indoors cannot be planted outside straight away. Instead toughen them up by placing them outside in a sheltered spot for a few hours during the day then bring them inside. Gradually increase the amount of time they spend outdoors . Do this for a period of one or two weeks before planting directly into the ground. 

Divide Primroses

These spring plants can become congested over time . To reinvigorate them  and keep them producing blooms in future years, divide after they finished flowering:

1. Dig them up: choose a cool day when the ground is moist
2. Separate the plants: Using a spade pull apart the clump or slice into sections.
3. Replant your divisions: backfilling the planting hole with compost or leaf mould. 
4. Water well. 

Prune spring-flowering shrubs 

Flowering shrubs such as forsythia, ornamental currants, viburnums, chaenomeles (flowering quince) need to be pruned straight after flowering towards the end of May, so there is plenty of time for new growth to develop and produce flowers next spring. 

1. Use sharp, clean secateurs or loppers for thicker stems and remove any dead or damaged growth to a healthy bud or to the base of the stem.
2. Prune out any stem growing in the wrong direction and spoiling the shape of the plant
3. If the shrub is very congested, thin out the stems by removing a couple from the centre of the plant right down to the base. 

Plant out summer bedding and sweet peas 

Towards the end of May, plant out begonias, tender salvias, pelargoniums, lobelias, sweet peas… Acclimatise plants to outdoor conditions  by putting them outside during the day and bringing them in at night for a week or two. Put the necessary support in place for climbing and trailing. 

Plant up baskets and window boxes with tender plug plants 

For long lasting summer colours it’s the right time to plant up hanging baskets and pots. If it becomes too cold for these plants to stay outside, keep your baskets and containers in a porch or greenhouse for a couple of weeks. 

Sow beans 

1. Sow dwarf, French and runner beans:  5 cm deep into deep pots of peat-free compost and germinate on a sunny windowsill. 
2. Set up supports ready for climbing types:  simply place three to four bamboo canes into the ground and tie to gather at the top. 
3. Plant the beans outside once they have established, from late May. 

Earth up potatoes

Once the stems are 20cm tall, draw soil up to form a ridge along the row. 

This protect shoots from frosty and excludes light, which turns potatoes green and inedible.

Grow salads

Ensure a continuous supply of fresh leaves by sowing a small amount of seed every two to three weeks. 

Plan for a winter harvest

Sow slower-growing vegetables such as cabbages, broccoli and kale for harvesting in winter. Sow seeds in module tray or seedbed for transplanting to final position later. 

Don’t forget 

• Keep on top of weeds: regularly hoe off or pull out annual weeds to prevent them establishing  and setting seeds.
• Get slug hunting: watch plants closely for signs of slug damage.
• Train climbers: tie in soft new shoots of climbing clematis and honeysuckle to their support. 
• Apply a mulch:  to retain moisture: late spring is the perfect time to apply mulch. Adding a 5-7cm layer will help to retain moisture before drier summer conditions arrive.
• Set up plant supports: put plant support in place before perennials get too big.
• Water wisely during dry spells: focus watering on newly planted specimens. Do your watering in the early morning or early evening to minimise water loss from evaporation. 

March is the month of spring but don’t forget that the weather can also have a more wintry feel. Stick to sowing indoors on a bright windowsill or in the greenhouse. March is also the month of longer days with plenty more time to get a head start in the garden.

Keep your flower garden sparkling

• Tidy tatty plants: cut back old stems and foliage to just above the ground, taking care not to snip off new growth. 
• Refresh containers:  check over planters, window-boxes and hanging baskets. Pick off dead or damaged leaves and flowers. Scrape away around 2.5 cm of compost from the top and replace with fresh compost. 
• Prune roses: March is your last chance to prune roses, but avoid days when frost is forecasted because the pruned stem may split. Prune to produce an open-centred plant for good air circulation and to encourage new growth.
• Prune fuchsias: cut back to one or two buds on each shoot to encourage a bushy growth.
• Cut back buddleias: cut back last year’s growth to short stubs, just above healthy buds or new shoots, to encourage strong and floriferous regrowth.
• Deadhead daffodils: snip developing seed-heads off so the plant directs its energy and nutrients back into replenishing the bulb. Leave the foliage in place as it will also feed the bulbs. 
• Cut back cornus: and other shrubs grown for their colourful winter stems to encourage new stem for next winter. Cut them right back to their base. 
• Penstemon: pruning back hard annually is recommended to avoid them becoming woody and leggy. It is best to wait until towards the end of the month or the beginning of April when there is no risk of frost. 

Preparing for colourful and wildlife-friendly plants

Fertilise and mulch your borders: mulch the surface with a 3 to 5 cm  layer of organic matter. It will improve the soil help to suppress weeds and trap moisture in the soil. 

Sow half-hardy annuals: zinnias, cosmos, nicotiana, marigolds, wildflowers….sown indoors in seed trays or plug modules by March or April will start flowering in June. 

• Use peat-free, seeding compost. Fill the seed tray with compost and level the surface by running a piece of wood over it to scrape off the excess. 
• Depending on the size of the seeds, either sprinkle then in a very thin layer or push the seeds one by one. 
• Sieve compost over the seeds and label your trays so you know what is growing.
• Using a watering can with a very thin rose head, gently water the seeds. An alternative, known as bottom watering, is to stand your tray in a shallow tray of water to properly saturate the compost. If using this method, pay close attention to how the tray feels, in terms of weight, once saturated (when the surface of the soil is moist) and use this as a reliable gauge for future watering.
• Cover the tray or plug modules with a clear piece of plastic, to maintain an even temperature and to keep the soil moist. Or use a bespoke propagator that has its own plastic lid. Place in a warm place indoors but not in direct sunlight.
• Remove the plastic cover as soon as the seeds have germinated. The young plants are ready to be “pricked” out when the second pair of leaves emerges. 
• Pricking out seedlings: handle them only by their leaves, not the stem. Fill a new tray or small pots with compost and plant seedlings about 5 cm apart, burying the seedling up to the base of the first set of leaves. 
• Pot individually: after 2 to 3 weeks the young plants will be large enough to be moved individually into pots or planted outside in well-prepared soil. Don’t allow the soil or compost to dry out and if you are planting outside watch out for slugs and snails. 

Divide perennials and ornamental grasses: early spring is the time to refresh herbaceous perennials and to propagate them. Large mature clumps of geraniums, astrantias or hostas can be split now to make more. Some ornamental grasses need division because they die out in the centre. They should be dug up with the outer vigorous sections replanted and the central dead part discarded.  

• Split plants into clumps that are small enough to handle but big enough to make an impact. Discard any old woody centres. 
• Dig up the clump using a spade an ensuring that you get all the roots. 
• Separate the clumps using and old knife, trowel or spade and replant small sections into their new positions immediately. Water them well. 

Transplant foxgloves: Many foxgloves self-seed around the garden and seedlings often appear near the parent plant. These can easily be transplanted to other areas where they have more space to develop. Try to get as big a root ball as possible. Most foxgloves are biennial and you might not get flowers in the same year that you plant the plants. If you want biennial foxgloves to self-seed around the garden and flower reliably every year, you will need to sow or plant them two years in a row. 

Get dahlias under way:  in the greenhouse or in a frost-free growing space, pot up tubers in peat-free multipurpose composts, with the buds facing upwards. Keep moist and place in a bright location until they are ready to plant out at the end of May.

In the vegetable garden

Dig in green manure grown over the winter. Do this while stems are still soft. Chop up leaves and stems with a sharp spade before burying them in the soil.

Weed vegetable seed beds. As the soil starts to warm up and days get longer, weeds will thrive. Keep on top of them before they have a chance to set seeds and spread. 

Dig compost and well rotted manure into your vegetable beds to prepare for the growing season ahead.

First outdoor sowings: cabbages, broccoli, cauliflowers, kale, corn salad, peas, broad beans, parsnip and turnips, beetroots, carrots, Swiss chard can all be sown from mid-March, directly outdoor. 

Sow seeds indoors: using the technique described above for half-hardy annuals, in seed trays or plug modules, sow, sweet peppers, tomatoes, cucumbers, courgettes, aubergines and salads. 

Asparagus: Weed and mulch asparagus beds. Asparagus has shallow roots so weed by hand to prevent damage. March is also the time to plant new crowns. 

Potatoes: are mainly planted in spring, over several weeks, according to the variety. Seed potatoes chitted in February are ready to be planted  from mid-March when the soil temperature has warmed up to 6-10 degrees. Potatoes like rich, fertile soil, so dig in plenty of garden compost or well-rotted manure.

Rhubarb: mulch with a thick layer of well-rotted manure to keep it healthy and to reduce moisture loss. Take care not to cover the crown.

Raspberry: 

• autumn-fruiting raspberry canes: cut to the ground to stimulate new canes, which will fruit in the autumn.
• Summer-fruiting raspberry: cut the tips of the canes that have grown beyond the top of their supports, cut just above a bud.

Fruit trees: mulch with well-rotted manure or garden compost, taking care not to mound mulch up around the trunk.

February is the month when dark days depart and when there are signs that spring is on its way. As the days get longer we are desperate to get out into the garden for some tidying and planting.

But as February is usually the coldest month of the year, hold off with any jobs involving plants that can be susceptible to the cold and wet. Focus on maintenance jobs and give borders a health check to ensure that they are tidy and healthy so plants are ready to spring into life come springtime. 

Also clean paths and patios, keeping them algae free to reduce slip hazard.

Bulbs

• Lillies bulbs can be planted out towards the end of this month in pots or directly in the ground.
• It is not too late to plant alliums, that will flower later than those planted last autumn. 
• Summer bulbs: Order bulbs now to plant them when all risk of frost has passed, 

Lift Snowdrops

It is the right time to lift and divide congested populations of snowdrops, replanting smaller clumps at the same depth as they were before.  

Cutting back and pruning

• Clear away old stems and seed-heads of perennials left to stand over winter, making space for new growth. 
• Prune summer flowering shrubs 
• Lavender: trim back the old flower stalks 
• Sedums: cut the brown stems down to ground level
• Ornamental grasses: cut deciduous grasses down to the ground before new growth starts to emerge.
• Shrub roses: remove dead or diseased stems and cut back repeat-flowering roses by a third to a half. 
• Prune late-flowering clematis (group 3 clematis): cut just above a pair of healthy buds about 30 to 60 cm above ground.
• Autumn fruiting raspberries: simply cut down all canes to the ground and apply a thick layer of homemade compost or mulch. 
• Wisteria: February is the last month to give wisteria a winter prune. Cut back the stems to two or three buds. 
• Fuchsia, penstemons: best to wait another month until you see signs of new growth. 

Sowing Annuals

• It might still be too cold to sow outdoors. The end of the month is a good time to give annuals a head start, indoors in a warm sunny windowsill, or a heated greenhouse. Once the seedlings are big enough to handle, transfer them to small pots to grow, before moving them in late spring in the ground or bigger pots. 

Chitting potatoes

Chitting is a way of encouraging potatoes to sprout before they are planted. That way they will crop a little earlier and will be more productive. 

February is a good month to start chitting seed potatoes in a light, cool but frost free place. Potatoes will need 4 to 6 weeks of chitting before they are ready to plant. This will give them a chance to sprout and start putting on growth. They will be ready for planting in mid-March to April when the soli temperature warms up to 6-10 degrees.

Mulch perennial vegetables

Spread a thick layer of well-rotted manure or garden compost, around asparagus and globe artichoke. This will feed them, suppress weeds and retain moisture