Skip to content
Search Magazine

April garden jobs: what to sow, grow and jobs to do

24 March 2021

Find out what gardening jobs for April there are do, including tips for spring lawn care and what flower seeds you can sow now.

April planting
Once the risk of frost has gone April is the ideal month for sowing seeds

April, as they say, is the cruelest month with sun one minute and frosty mornings and bitter winds the next. In the April garden tender young leaves are prone to frostburn and judging what to do when is tricky. Even if it is warm enough to start sowing always keep to hand some horticultural fleece or bubblewrap to cover vulnerable young crops.

What to plant in April

Flower seeds to sow in April

If you haven't already sown sweet peas now is your last chance. Sow into deep pots or roottrainers as they dislike disturbance to their roots. Or, instead, look out for young plants in nurseries and garden centres. Check whether they are grown for scent or for cutting. Some longer stemmed varieties may smell less strongly.

Sow marigolds, petunias, nasturtiums, asters, zinnia and salvia indoors or in the greenhouse. 

Outdoors you can sow native wildflowers and hardy annuals such as poppies and sunflowers.

Read our guide to sowing seeds

Give your garden a makeover and save money at the same time with a special Thompson and Morgan offer of 10% off.

Vegetables to plant now

The soil is now warm enough for seeds to germinate so, once the nights begin to warm up, try to find room for some carrots, parsnips and beetroot. Make a wide drill, about 5in across and water it well. Sprinkle the seeds thinly across the width of the drill, because this avoids having to thin and disturb seedlings. Cover thinly with soil and protect from cats, birds and the like with wire or sticks. Early carrots, such as Amsterdam Forcing, should appear within 14 days. Cylindrical beetroots mature faster and ‘Alto’ F1 will probably take 20 days. Parsnip F1 ‘Gladiator’ will take 30 days to appear. All three have an AGM – or Award of Merit.

Start sowing spinach and chard. These can go direct into the soil and will need to be watered well until they get going. Avoid letting them dry out or they might bolt.

Sow broccoli, kale and Brussels sprouts for winter. Sow individual seeds into modules and leave to germinate either in the green house or a window sill. They should appear within a couple of weeks. Once they have reached about four inches they can be hardened off and then planted outside.

Sow runner and french beans two to a small pot indoors or under glass. Keep the soil moist and they should soon germinate.

Potatoes need to be planted this month. As a rule new potatoes go in early to mid April. Maincrops follow in the second half of the month but exactly when you plant your potatoes will depend on the conditions in your area. If in doubt ask a local gardener or garden centre. You want to avoid the emerging foliage being burned by frost. Plant somewhere sunny into a six inch deep trench lined with garden compost. New potatoes (also known as First and Second Earlies) should be spaced a foot apart. Leave 15 inches between maincrop tubers.

Plant herbs like rosemary, thyme and oregano. Any that have become leggy can be trimmed to suit the space. You can cut rosemary into the wood if it has become wild and straggly. If you grow on clay or badly draining soil it’s a good idea to put some grit in the base of the planting hole to help with drainage.

Garden jobs for April

Harden-off greenhouse plants 

Start hardening off greenhouse grown plants to give them a chance to toughen up and make them better able to withstand pests and weather. Choose a clement day to begin and start by putting them outside, out of cold winds, strong rain or sun and somewhere out of reach of marauding slugs. Allow a week or two before planting out, once all chance of frost has passed.

Prune buddleia

Prune buddleia down to a woody framework about a foot high above ground. Watch out not to hurt your hands with the tough repetitive work. I find loppers are often easier to use than secateurs.

Tend to the the lawn

Start mowing the lawn, if you haven't already. If the grass is long make sure to mow on dry days and start with the blades high, reducing the height by stages as the grass becomes stronger and more maneagable.

This is the perfect time to give your lawn a bit of TLC. First rake off loose thatch and moss. This enables the grass to grow healthily during the season. Or, if you have one, avoid straining your upper body by using a mower with a special thatch removing cartridge attachment.

Next, either using a proprietary aerator attachment, or a garden fork (which can be very tiring work), make holes across the lawn to help aerate the soil and prevent compaction. If you’re using a fork dig to a depth of about three to four inches and wiggle the tines to remove. Sprinkling sand into the holes also helps.

How much you want to remove weeds will depend on you and your lawn. Some people like to use a weedkiller, others prefer to pull individual weeds by hand.

Once you have removed the weeds and moss to your liking topdress the lawn with a feed and conditioner.

If there are any bald patches you can resow these now. Small patches can be targeted with special feed and seed mixtures. Check in your garden centre for the treatment that you need. You can buy mixes designed for high use areas and for shaded areas. Some mixes even contain neutralisers to prevent pet urine marks.

Tidy the edges of the lawn where they meet flower borders. First mark a straight line using string held taught between two posts. Using a half moon lawn edger, follow the string, cutting away ragged edges and throw these away. This isn’t just a job for houseproud gardeners. Cutting the grass away prevents weeds and grasses growing into flowerbeds.

Find out more about spring lawn care

Trim penstemons

Penstemons are bee-pleasing flowers that perform from summer until late autumn, if deadheaded. They hail from warmer areas on the western side of North America, so they’re borderline hardy and need a topknot of foliage to survive winter. In April, new shoots appear at the base. Trim the leggy stems right back to keep your penstemons compact and vigorous. It’s also a perfect month to take cuttings, from 3in snippets, and plant new ones.

Plant biennials and perennials

Perennials and biennials such as foxgloves can be planted in the ground now.

Start off dahlia tubers

April is perfect for potting up dahlia tubers, because they’ll make fine plants in time to be bedded out by early June. Pinch out the shoots once, to make them bushier, and stake taller varieties when planting using a tripod of three canes. Dahlias make fabulous cut flowers and they will often flower in November now that autumn comes later.

Feed containerised plants and borders

Boost pre spring growth in pots and borders with blood, fish and bone or other fertiliser

Tend to the vegetable patch

Check to see if any previously planted onion sets have been pulled out by birds and tuck them back in again or replace with spare sets if you still have some.

Hand pull emerging weeds before they get bigger. Avoid letting them flower and setting seed which will only continue the cycle. Or, if there are already many, you may need to pick up the hoe and work it between the crops rows.

Look out for emerging asparagus stems and remember to harvest them before they become woody.

If strawberries are coming in to flower keep an eye out for frosts and cover plants with fleece or you will lose the crop.

Look out for dwarf fruit trees or varieties that can be grown in large pots. There are many to choose from and this is a good time to buy and plant.

Browse a wide range of fruit and vegetable varieties from Thompson & Morgan, where Saga customers can get 10% off.

Tidy up trees and shrubs

Cut off any frost damaged leaves or tips from flowering shrubs to prevent further die back.

Fruit trees will benefit from having weeds cleared from their base and apply a layer of mulch to conserve moisture. You can use composted garden waste, grit or bark but if the mulch is nutrient free (eg bark, grit) give a feed first.

Visit our spring garden section for more tips to maximise your April garden

Try 12 issues of Saga Magazine for just £15

Subscribe today for just £29 for 12 issues...

The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.