Seeds to sow now:

Indoor or in a heated greenhouse

Coriander

Cress

Forget-me-not

Ornamental pepper

Outside

Alpine wallflower

Alyssum

Amaranthus

Aubretia, Rock cress, Aubrieta, Aubrietia

Basil

Beet, Beetroot, Chard

Beetroot

Cabbage

Canterbury bell,

Cardoon

Carrot

Common wallflower

Courgette

Cress

Double daisy

Foxglove

French bean, Fine bean

Kohl rabi

Lettuce

Marrow

Ornamental winter kale

Pansy

Radish

Runner bean

Spinach

Spring onion

Sweet William

Turnip

Other things to plant outside now:

Outside under cover

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.

• 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.
• Cut runners from strawberries (unless trying to propagate more plants). Runners will divert energy away from crop production.
• Earth up the first early potatoes that were planted in March, to stop the tubers being exposed to light, turning green.
• When the leaves of cyclamen have fallen, stop watering and allow the bulbs to dry out.
• Tidy up in the greenhouse now that you have moved bedding plants outside.
• 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

• Plant out greenhouse grown runner beans or sow them at the base of wigwams 5cm (2in) deep. Keep well watered.
• 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.
• Bluebell leaves will have yellowed, so they can be lifted and divided.
• Tomato plants can be moved outside. If growing them as 'cordons' nip out the side shoots
• We have probably now seen the last of the frosts. Summer bedding plants can safely be brought outside from the greenhouse or purchased from the Garden Centre.
• Remove spring bedding plants and lift and store spring flowering bulbs (with the exception of snowdrops).
• 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.
• Plant up hanging baskets. More information available here.
• Buy plants in strips or trays that are compact and sturdy, the compost that they are growing in should be moist. Try to buy plants in bud, with few open blooms.
• Paint shading on the greenhouse glass, or use shading to lessen the scorching effect of the sun and to keep temperatures lower.
• Trim hedges to encourage the branches to thicken up and to keep them neat and tidy.
• Plant tender perennials including pentstemons and salvias.
• Propagate marginal pond plants. Take short cuttings, remove lower leaves and push stems into pots of mud. Keep top of the pots just under the surface of the water.
• Sow hardy annuals in their flowering positions to fill any gaps in the border.
• Check gooseberries for sawfly. Prune this year's growth back to 4-5 leaves (this shouldn't affect fruit as they appear on old wood).
• Pinch out the growing tips of annuals and some perennials to create a stockier plant and to encourage more flowers More information here.
• 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.
• Check the ties on climbers, flower stems and standard roses - the tops of plants can get very heavy when in full bloom or when wet.
• Take soft wood cuttings from thyme. Thyme cuttings take easily, so they can be stuck in the soil or in pots. Remember that thyme likes full sun and hates to be grown in the shade.
• Depending on recent weather conditions and daytime temperature, gooseberries should now be ready to be picked.
• Apple and pear trees will shed some fruit, this is known as the 'June drop'. This is quite natural, it's the trees way of restricting the amount of fruit that develop.
• Feed established roses, fortnightly, with a rose fertilizer, dead-head regularly and check for aphids and black spot.
• Apply a weed and feed to established lawns. Water in with a hose after a few days if it hasn't rained.
• Stake and tie perennials to prevent them being broken by wind and rain. Remove fading delphinium flowers to encourage a second flowering.
• 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.
• Cover strawberries and fruit bushes with netting to protect them from birds. Start to feed the plants weekly when the fruit starts to form.
• 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.
• Ensure that soil in hanging baskets and patio planters is kept moist, watering daily in dry weather or where baskets and containers are close to the house and may be in a 'rain shadow'. Removing fading and dead flower heads from plants will encourage new flowers to form and bloom. Feed plants in containers weekly with a liquid fertiliser, particularly if a slow release fertiliser wasn't mixed with the potting compost when planting up the baskets and containers.
• Continually nip out side shoots from upright (cordon) tomato plants. These reduce the amount of food available to fruit baring branches. If growing plants in the greenhouse, nip out the growing tip after the plant has produced 4-5 fruiting trusses, reduce this to 3-4 if growing tomatoes outside. See here for more information : https://www.youtube.com/watch?v=zFBgCBaFSnk&ab_channel=UKGardening
• Lift, divide and replant chives.
• Move houseplants outside for some summer sunshine.
• If you are going away on holiday, prepare your garden a few days before you leave. Water all shrubs well, including roses and climbers, and lay a 50-75mm (2-3in) thick mulch around the base of the stems, to keep the roots cool.
  
  If you are fortunate enough to have a neighbour willing to water your baskets, greenhouse and borders, make the task easier by unravelling and connecting up the hose and leaving filled watering cans in accessible places around the garden.
  
  If you don't want your neighbour to come into your house, whilst you are away, move any houseplants outside so they can be watered, any orchids, cacti or succulents should be fine left indoors without water for a couple of weeks.
  
  If you don't have anyone to check on your plants, put all of your pots (including house plants), containers and hanging baskets (to stop them tipping over, sit them on large, empty flower pots) on the patio or lawn. Put the lawn sprinkler or sled sprinkler bar between them, connect the hose to an outside tap using a water timer (set the timer to come on twice a day, once in the morning and once in the evening - 10 to 15 minutes each time should suffice). Test the settings and batteries before you go away.

Recent articles:

• Creating a compost heap
• How to lay a new lawn
• UKGardening YouTube Channel
• Tweets by UKGardening.
• Removing large branches
• Updated photo gallery