On the Lawn
Mow lawns when necessary - whenever the grass is growing. Add the clippings to the compost heap in thin layers.
Sowing new lawns or over-seeding dead patches can be carried out from mid-April to early May. Do not walk over or mow newly sown grass until it has reached a height of 5-7.5cm (2-3in), and then only give it a light trim at the highest setting. Apply a high nitrogen spring lawn fertiliser at the beginning of the month to encourage good, strong growth.
If moss is a problem choose a combined fertiliser and moss-killer. Lightly rake lawns with a spring-tine rake to remove old plant debris and dead moss. Sow seed over the existing grass, around 25g per square metre. Apply an organic fertiliser and water in well. When the grass is 5cm (2in) high, cut again.
The Shrub Border
Feed hungry shrubs and roses with general fertiliser, use a hoe to gently work the fertiliser granules into the soil. Keep weeds under control don’t let weeds flower.
Flower border/Patio area
Hardy annuals can be sown in pots, modules or directly onto a prepared area of the border to provide colour in the garden. Modular trays are useful for sowing half-hardy summer bedding plants such as marigolds (Tagetes), Lobelia, and Petunia. Label each seed tray, follow instructions on labels and seed packets.
Remove any frost damaged shoots from evergreens damaged by earlier cold weather. Lightly cut back lavenders to prevent them getting too leggy and woody. Loosen any tree ties that are digging into the bark. Take cuttings of your favourite conifers.
In the Vegetable and Fruit Garden
Protect fruit blossom from late frosts by using horticultural fleece.
Now is a good time to sow herb seeds. It is now safe to prune plum and cherry trees, keep pruning tools clean to help prevent the spread of infection from tree to tree.
You can still plant container-grown fruit trees and bushes, as long as the ground is not too wet or frozen. Incorporate lots of well-rotted organic matter (composted green waste) into the planting soil when refilling the planting hole or trench.
To encourage flowers and fruit you should add some High potassium feeds (such as tomato fertiliser) this month.
Potatoes can be planted in deep drills or in individual planting holes, with 5cm of soil mounded over the top. Alternatively, plant them through slits in black polythene mulch. Sow beetroot, carrots, Swiss chard, summer cauliflower, kohl rabi, lettuce, leeks, radish, turnip, spring and pickling onions, peas and perpetual spinach in well-prepared soil.
In the Glasshouse and Conservatory
Increase the watering of indoor and conservatory plants as days lengthen. Liquid feed once plants show signs of growth. Seedlings will need daily attention be careful not to over water or allow them to dry out.
Give glasshouse plants more space as they put on new growth. This will help to prevent disease, and to contain early pest infestations.
Ponds
Divide or cut back marginal and bog garden plants if overcrowded.
It is best to raise small plants in baskets onto bricks when first introduced then slowly lowered to the bottom of the pond as they increase in size.
Clean out pond filters.
Start feeding the fish. Tidy up plants in the bog garden, and mulch with composted bark (or similar).
Rose beds
Tie in climbing and rambling roses as near to horizontal as possible. This will restrict sap flow causing more side-shoots to grow along the length of stem. Therefore more flowers will be produced. If allowed to grow directly upwards only the top section will flower.
Flower border
Continue to protect lilies, Delphinium, Hosta and other new shoots from slugs and snails.
Vine weevil grubs can begin to cause damage to plants at this time of year, first signs will be plants beginning to wilt, check the roots for signs of damage and look for larvae.
The Compost Heap
Turn/moisten compost heap/bin. Compost all green waste.
And remember – minimise your waste!
Add all green waste, including vegetable peelings from the kitchen, to your Compost heap or Compost bin. Recycle Paper, Cardboard, Glass Bottles and Jars and Plastic.
Collect rainwater in a water butt for the glasshouse, and investigate ways to recycle water for irrigation.