Seeds to sow now:

Indoors or in a heated greenhouse

Ageratum

Alyssum

Aubergine

Bell pepper, Pepper, Sweet pepper

Cardoon

Celeriac

Celery

Columbine

Coriander

Cress

Cucumber

Floss flower, Ageratum

Forget-me-not

Ornamental pepper

Pepper

Tomato

Outside

Alyssum

Amaranthus

Antwerp hollyhock, Fig-leaved hollyhock, Hollyhock

Asparagus

Aubretia, Rock cress, Aubrieta, Aubrietia

Beetroot

Beetroot, Garden beet

Borecole, Kale

Bristly hollyhock

Broccoli

Brussels sprout

Cabbage

Carrot

Cauliflower

Common hollyhock

Hollyhock

Kohl rabi

Lettuce

Normandy sorrel

Onion

Ornamental winter kale

Radish

Spinach

Spinach, Summer spinach

Spring onion

Sweet pea

Sweetcorn

Turnip

Outside under cover

Brussels sprout

Courgette

French marigold

Leek

Lettuce

Marrow

Onion

Snapdragon

Sweetcorn

Tomato

What else to plant now:

Roses (bare rooted)

Potatoes (main crop)

Shows and events:

I have checked the events listed below and have added comments where necessary. Please check the show website before travelling, as some events are very popular and the venues may have put restrictions in place, others might have to be cancelled at the last minute.

All event details have been entered as accurately as possible, but please check with the event organisers before travelling to avoid disappointment.

The UKGardening web site has been running since 1998. The idea behind the site has always been to provide what we think will be interesting and useful information for the novice gardener.

Jobs to do in the garden this week.

• When you see the new shoots forming on sedum, cut down the old, dead flower heads.
• Refirm the roots of any shrubs that may have been lifted by frost.
• Tidy up any remaining leaves and general garden rubbish. It's home to slugs, snails, vine weevil and woodlice and can introduce disease and infection into your garden.
• April is the peak flowering time for orchids.
• April is the best time to plant an evergreen, such as laurel or box.
• Lift and divide primulas and polyanthus after they have finished flowering. See our YouTube video showing how to do this.
• Keep an eye on the weather forecast. Cover shrubs that are likely to be damaged by frost with garden fleece, sacking or an old light blanket.
• Open cloches ends to allow pollinating insects access to flowering plants. Remove cloches in late spring.
• Don't be tempted to buy your summer bedding yet, unless you have a greenhouse, conservatory or cold frame that you can store them in. A late April / early May frost is not uncommon in the UK.
• Plant up new ponds with aquatics, including oxygenators.
• Prune lavatera hard, down to healthy young growth.
• As daffodils fade, remove the flower heads. Don't cut back the leaves - leave them to die back naturally. However if you want to tidy them up, wait until the leaves have yellowed before removing.
• Now is the best time to plant lavender. Widely grown for its scent and foliage, lavender is ideal for borders or a low hedge. Available in shades of purple, blue, white and pink it is a magnet for bees and butterflies
• Postion plant supports where they will be needed in late summer. Doing this now reduces the risk of damaging the roots later in the season.
• Plant maincrop potatoes in prepared ground or potato growbags.
• As summer-flowering herbaceous perennials start to come back to life, lift and divide overgrown plants.
• Plant onion sets (bulbs). Run a string line across the bed and plant the bulbs, 5-10cm (2-4in) apart, up to their necks so just the tips are showing. Space the rows 25-30cm (10-15in). Firm the soil around them and water well, cover with a cloche for added protection. Keep an eye on them until they get established as some birds like to pull the sets out.
• Begin regular cutting of your lawn. If the grass is long increase the height adjustment of the mower to the highest setting. Once this first cut has been done, lower the blades/deck and go back over the lawn.
• Remove algae and moss from patios and paths with a pressure washer or proprietary patio and path cleaner (traditionally a tar oil winter wash could have been used, but these are no longer available, particualrly to the amateur gardener, as they were found to be carcinogenic).
• If becoming boisterous, prune spring-flowering clematis including alpina and macropetala after flowering. Use cuttings to propagate new plants.
• Thin out seedlings, leaving the strongest growing plants. Water the soil gently beforehand to reduce soil disturbance.
• If your lawn is more moss than grass, then treat with a lawn moss killer. Bare in mind that the moss will turn black within a couple of days, so don't be too alarmed. A couple of weeks after application, if you are left with bare patches in your lawn, mix equal quantities of grass seed and seived compost and scatter over the patches, cover areas with fine netting or twigs gently pushed into the soil, to protect from birds and animals. Combination lawn feed and moss killer is available, but feeding your lawn when it's not necessary will encourage it to grow quicker and therefore need to be cut more regularly.
• Scatter growmore granules under fruit trees and bushes, especially apple, pear and plum trees. If it doesn't rain for a couple of days, water the granules in with a hose or watering can. Growmore is a slow release, general fertiliser, it includes the three main plant nutrients (nitrogen, phosphates and potassium).
• Transplant any self-set aquilegia, lupins and hollyhocks to new locations.
• As it's starting to warm up, it's a good time to lay a new lawn, although the best time is in Autumn or late winter, as it's damper and cooler, allowing the turf to bed in without you having to worry too much about regular watering. See here: laying a new lawn for further information.
• Remove the dead heads of spring flowering bulbs, such as tulips and daffodils, before they have a chance to produce seed. This will encourage the plant to store energy in the bulb rather than wasting it on seed production.
• Control weeds in lawns with a selective weedkiller. Don't cut the grass for at least a week after applying. Don't put these grass cuttings on the compost heap.
• Your pond may have started to turn green and cloudy. This is due to a rapid increase in algae, which flourish in the warmer spring temperatures. Once the pond plants start to grow again, especially the oxygenating plants, these will use up the nutrients and create shade, reducing the amount of algae. To speed up the clearing of the water, drop a small string bag/pair of old tights stuffed with barley straw, into the pond. Weigh the straw down, so that it floats just below the surface of the water.

  As the straw breaks down, it produces hydrogen peroxide, which reduces and inhibits the growth of algae and blanket weed. If the algae is particularly bad, barley straw extract can be bought in liquid form and added to the pond water (follow the instructions on the bottle, but as a guide before purchasing,125ml treats approximately 4,500 litres/1,000 gallons, but multiple, fortnightly treatments through the year may be necessary). If you have a fountain or waterfall, try to position the barley straw underneath this. Remove and replace the barley with new straw after about six months, before it completely rots down, polluting the water.

  The small, pre-filled barley straw bags to add to your pond, cost about £2 each, but you can buy a 17 litre pack, which will last a few years for about £10 from your local pet shop or Amazon here: Supreme Petfoods Tiny Friends Farm Russell & Gerty Barley Straw, 17 Litres

• Sow vegetable seeds (courgette, marrow, runner and French beans) in the vegetable patch and salad seeds (lettuce, spring onion and radish) little and often to provide a staggered harvest through the summer.
• Lots of tender plants can be grown outside in containers between May and September as long as the pot is big enough and they get enough water and the occasional feed.
• Spread compost from the compost bin over the borders and vegetable patch. This adds valuable nutrients to the soil and acts as a mulch, to retain moisture and reduce weed growth. The ground should be weed free and the soil moist before adding a layer of compost or mulch.
• Feed established roses every other week with a rose fertilizer. Deadhead regularly to encourage further flowering. Check for aphids and black spot and treat accordingly.
• Apply a weed and feed to established lawns. Water in with a hose after a few days if it hasn't rained.
• The adult vine weevil, the number one garden pest, will be emerging from the soil as the temperatures rise.
• Protect plants from slugs and snails with slug pellets, course grit or traps. Alternatively try to encourage birds, hedgehogs and frogs to your garden - all prey on slugs and snails. More suggestions to reduce slug and snail damage.
• To reduce the chance of introducing infection when pruning or deadheading, wipe the blades of secateurs, loppers and snips with a rag soaked with a garden disinfectant, such as Jeyes fluid, which can also be used to wipe down garden tables and chairs.
• Regularly water trees and shrubs that were planted last autumn and winter. Their roots won't have had a chance to fully develop yet.
• Cut grass weekly, long grass takes more nutrients out of the soil. It is also harder to cut and may leave yellow patches in the lawn.
• Lift, divide and replant chives.

Recent articles:

• Creating a compost heap
• Enjoy the vibrant blues and wonderful scent of bluebells.
• YouTube: Propagating snowdrops (Galanthus) by bulb division
• Sowing seeds
• How to lay a new lawn
• UKGardening YouTube Channel
• Tweets by UKGardening.
• Removing large branches
• Updated photo gallery