Lunch outside is the measure of good weather in Spring. The first day you can have lunch outside without freezing to death whilst simultaneously pretending that you having a great time and longing for a really hot fire to stand by, is either a freak of climate change or – April. You can also have snow, frost and heavy rain but it is a cruel year when there are not a few days of shirtsleeve sun in the middle of the day.

The garden responds to this extra light and heat by burgeoning. April is the month of growth. Only October can match it for transformation from the beginning to the end of the month. In a normal year (and in truth this year has NOT been normal ) April begins dominated by bare brown branches and bare brown soil, the grass still a lustreless winter green and ends with the long days full of the billowing majesty of Spring, heavy with leaf and alight with flower and – really importantly for me – the sky traced by the great swooping arcs of the swallows that have come home for their summer season.

There is still more to come of course but perhaps that is why I love it so much. It delivers all you might possibly desire along with the absolute certainty of even better to follow.

What to do in the garden this month:

April is the busiest month. The round of jobs remains much the same from year to year but there are always more of them than hours in the day. For a gardener this is heaven as it means you can spend all the daylight hours you have out in the garden doing the work you love.

The important thing is to get on top of things. So cut the grass, weed as much as possible, get perennial plants in the ground, finish mulching, sow some seeds – but in a manageable, enjoyable way. Keep it simple. There is still time to spare. And if there are jobs that you ‘ought’ to have done much earlier there are two sensible approaches. Either do them right now, a bit later than you should, or leave them till next winter. But having made the decision, act!

Mowing

Many of you will already have mown your lawns a few times already but a a word of advice for all of you as well as those that are yet to begin. Resist the temptation to scalp your grass down to its midsummer height. Set the blades high and just trim the grass for the first few weeks as much to even it out as to reduce it. Then, as the weather gets warmer and the grass starts to grow more strongly, gradually reduce the height over a few weeks but always keeping it slightly on the long side. This will result in a much healthier, greener sward.

Add all clippings to the compost heap but mix it well with dry, brown material like straw or cardboard which will stop it becoming a wet, green sludge.

Plant out sweet peas

The time to plant out sweet peas into the garden is mid-April in the south and towards the end of the month further north.

Sweet peas grow best in rich soil with plenty of moisture and in cool – but not cold – conditions, so the more you can enrich the soil with lots of compost or manure before planting, the better they will grow. I like to grow mine up bean sticks arranged as a wigwam but any support will do from bamboo canes to chicken wire.

I plant two or three plants to each stick or support and water them in very well, before mulching them thickly to keep them weed-free and to stop them drying out.

One word of caution. The aim is to grow strong, healthy individual plants so if you buy a pot with lots of seedlings I think it better to divide each pot into two or three. Then plant these sections at the base of each support so they have less competition and you should end up with more flowers.

Plant new potatoes

Whilst there is no rush to plant maincrop potatoes (I have planted as late as June and still had a good crop) the sooner you can plant seed for first earlies, the sooner you can enjoy that delicious harvest that always tastes so much better than any that you can buy.

Make a V-shaped trench 6-9 inches deep and place the seed potatoes about 12 inches apart along the bottom of it. Backfill the trench so that the soil forms a ridge along the length of it. Leave at least 3ft between rows to allow for earthing up – digging more soil onto emerging foliage to protect them from late frosts. I also grow them in a raised bed simply pushing each seed potato in a 6 inch deep hole made with a dibber with each plant about 18 inches apart in a grid. However you plant them, always enrich soil for potatoes with plenty of well-rotted manure or compost.

Tidying bulbs

Although you should resist any temptation to cut back, tie up or ‘tidy up’ the foliage of any bulbs that have finished flowering as this will decrease the quality of flowering next spring, you can lift the bulbs, foliage, bulb and roots and pot them into a container which can then be put to one (sunny) side to die back and feed next year’s bulb without leaving an unsightly mass of dying foliage in a prime position for the next few months.

When the foliage has died back the bulbs can be stored in the pot, making sure they do not become too wet (they can dry out completely) and then replanted in autumn.

Dead head Azaleas and rhododendrons

This is a very simple job but one which is often overlooked. To extend the rhododendron and Azalea season and ensure that the plant does not waste its energies into seed production, dead head as many faded flowers as you can. This is particularly relevant to the large-flowered varieties.

Do not use secateurs as you risk injuring the fragile buds growing at the base of the flowers but gather the flower trusses between finger and thumb and snap them off.

Removing the withered flowers also reduces the risk of fungal infections and will increase next year’s flowering display. As well as doing the plant good it also removes unsightly dead flowers that can hang onto the shrub for days or even weeks.

Harden off tender plants

Although there is still a risk of frost in my garden – and especially so the further north you go – it is time to start bringing tender plants such as Fuchsias, citrus, brugmansias, bananas, agapanthus or Cannas outside so that they can gradually acclimatise before being planted out into a border or pot.

It is not so much the absolute temperature as the variations between night and day that they must become used to. Put them outside in a sunny but sheltered spot and have some horticultural fleece to hand to cover them if there is a cold night, but let them get used to the changes in temperature and exposure to wind and rain that they have not had to face over the past few months for at least a week – and preferably two – before moving them to their final position after the risk of any frost has passed.

Planting lilies in pots

Plant lilies in pots for one of the best and most fragrant of summer displays. Most lilies like an ericaceous soil but Madonna Lilies, which are one of the first to flower, prefers an alkaline soil and will return year after year given the right conditions.

But you will not go wrong if you provide good drainage and a nice, loose compost. I achieve this by mixing in plenty of leafmould and grit into a bark-based general purpose compost but just adding perlite or vermiculite will help greatly. Plant the scaly bulbs with about 4 inches of compost above the crown and put them somewhere lightly shaded to grow. Keep them well watered and move them to their final position when the buds develop in May and June. In general lilies like shady roots and sunny flowers so a west or east facing sheltered spot is ideal for their flowering performance.

Support herbaceous plants

The purpose of plant supports is to prevent any damage rather than to repair it, so the correct time to support any plant is before it needs to be done. The best way to do this in a border is to establish a system of supports that you put into place just as the herbaceous plants are starting to grow strongly, so that within a few weeks the supports will be hidden but quietly doing their work with the tender but vigorous new growth contained within their gentle, protective embrace.

I use a mixture of home-made metal supports, pea sticks (essentially bushy prunings from the garden) and canes with twine. Whatever you choose try and anticipate the growth and make the support adjustable or flexible to adapt a little. If you can make it decorative so much the better. But getting it into place now will avoid trying to rescue damaged plants in a month or two’s time.

Design tips for a small garden

The first essential tip in designing a small garden is to keep it simple. One clear idea done well works best. One design style, one overriding theme and a sense of relaxed unity.

This applies to borders as well. Work out the effect you are trying to achieve, from a busy riot of herbaceous perennials, the cool sensuality of grasses or a working veg patch, and focus on that as the guiding theme.

One of the most common mistakes people make when designing a small space is to think that everything in it must be small. The opposite is usually true. A few large plants make a space seem bigger whereas lots of small ones make it feel crowded.

Any outsized object or plant can look perfectly at home in a tiny space as long as you are ruthlessly selective about it. If it does not look absolutely right then get rid of it. There is literally no room for compromise. You must ask yourself about every individual plant, every paving stone, each pot, whether it is the best use of that particular space, whether it is the right thing in the wrong place.

I would argue that small gardens should never have a lawn as a paved area will work in all weathers, is ideal for containers of all kinds and does not need mowing.

Finally, plant for all four dimensions, height, breadth, depth – and time. A small garden must work for you every day of the year. Use bulbs, annuals, climbers with good foliage as well as flowers – anything to extend the range of display within the garden and thus maximise the potential of the limited space.

April 2019