Gardening Monthly Calendar - April
Apr 25th 2018 ⋮ in Advice

What to do in your garden in April?


With the plenty of daffodils and tulips dotted about and flowering trees now in bloom, it’s time to put some thought in to preparing your garden for the coming months. It’s likely that there will be a few warmer days during this month but also plenty of April showers expected. Be mindful that frosts can still occur if the temperature drops low enough, so make sure tender plants are still protected where needed.

This month hardy annuals can be sown into pots, adding a bit of colour to your gardens. Half-hardy summer bedding plants such as petunias and marigolds can be put outside when warmer weather is guaranteed, and kept under cover or heated when temperatures are cooler.

Now that the weather is brightening up, it’s likely that you’ll notice more and more weeds creeping up through patios and edges. Weeds can be eradicated without the need for chemicals, but it does require a fair bit of effort to manually remove the weeds. When weeding, try to pull up as much of the root or bulb as possible to reduce the chances of the plant re-growing. Barriers can be used to help prevent weed growth by covering the areas 4-6 inches with deep organic mulch such as wood chippings or bark to smother the weeds. To keep your garden clear of weeds, they will need to be pulled up or controlled with chemicals fairly regularly.

Sweet peas can be sown outside this month and plant out autumn sown sweet peas from pots.

If not done already, cut back any dead or dying foliage on ornamental grasses and perennials to promote new growth.

Towards the end of April, summer hanging baskets can be planted up using water-retaining gel and slow-release fertiliser.  Herbaceous perennials can still be planted into well-prepared soil.

To get a larger and better display of flowers, some perennials including lupins, phlox and delphiniums will benefit from having their flowering shoots pruned. Deadhead faded daffodil and tulip flowers but leave the foliage to die off naturally. Deadhead spring bedding plants which can increase how long they will flower for if they are removed regularly.

If the weather has been warm, tubs and containers can dry out so check whether they need watering and top up with fresh compost.


During milder times of the aphids, caterpillars and other pests can multiply quickly. Keep a check sweet pea plants in particular and remove early infestations by hand. New shoots of lilies, delpiniums and hostas will need to be protected from slugs and snails.

Rabbit guards around the base of newly planted trees and shrubs can be used to protect the bark.

Trees and shrubs

If the temperature is still relatively cool but not cold, evergreen trees and shrubs can be planted and moved as long as the soil isn’t waterlogged. When the weather becomes warmer and dryer large plants can be at risk of establishment problems so it may be an idea to hold off from planting them until October.

Add a 2-3 inch layer of organic mulch to shrub beds to help retain moisture when the weather dries out.

A balanced fertiliser blood, fish or bone should be used to feed trees shrubs and hedges, which will benefit damaged or weak plants.

Trim back lavender to prevent the plant from becoming overly woody. .


Now is the time of year that lawns will need more attention. As the grass is growing again, it is better for the lawn to keep the grass at a constant height. After mowing your lawn, the grass clippings can be added to your compost heap but in thin layers so it can properly aerate. At the beginning of the month, a high nitrogen spring lawn fertiliser can be used to encourage healthy growth. A combined fertiliser and moss killer can be used if moss is a particular problem. Now is the best time of the year to be applying lawn weed killer. Using a spring-tine rake, lightly rake the lawn to remove dead leaves and debris so that as much light as possible is reaching the lawn.

New lawns can be sown from late-April to Amy as long as the soil isn’t too cold or moist. Newly sown grass should not be walked on until it has reached a height of at least 2-3 inches.


Space out any plants you have in the greenhouse before they have a growth spurt, which will help prevent any disease from spreading.

The greenhouse should be kept at a minimum of 5℃ to protect tender plants from the cold.

Shade netting can be used on the greenhouse if the weather becomes to warm to prevent any plants from becoming sun scorched. If the nights are still relatively cold, a heated propagator or a fleece covering can be used to help prevent young plants from the effects of temperature fluctuations.

Splashing water on the floor of the greenhouse can help the humidity levels in the greenhouse when the weather is particularly dry and sunny. However, too much humidity can encourage grey mould so try to get the balance right and regularly open vent and doors.

Clear up fallen debris and compost and pick off dead leaves to help prevent pest and disease spreading.


Dig in at least a 5cm deep layer of fresh compost or green waste in to your the beds that your area preparing as vegetable area to get ready for the growing season.

Chitted potatoes can be planted directly in the ground or in potato bags.


Plant out strawberry beds or containers but enrich the soil with well-rotted manure first, and cover with a cloche for earlier crops.

Apply well-rotted manure or garden compost to the base of fruit trees, being careful to not mound too much mulch up around the trunk.

Odd Jobs

Using a hard brush or a jet wash remove dirt and algae from walls and patios, ready for when you want to sit out and enjoy your harden in the summer months.

Wooden garden furniture and sheds can be treated with wood preservative and stain during dry weather.

Houseplants should be watered more frequently as the temperature increases. Feed houseplants with a liquid feed when they are actively growing (between March and September). For flowering houseplants choose a feed that is high in potassium, whilst foliage plants prefer a more balanced feed.