After the first week or so of May, in Berkshire, it is usually safe to assume that the risk of frost has passed, so gardeners’, thoughts can start to turn to preparations for summer.  This year however, has seen an unusually cold April with regular overnight frosts, so we will be keeping plants under cover until we are sure that they will be safe outside.

Once you’re confident that the weather has turned, tender bedding like Pelargoniums and Begonias and perennials such as Dahlias and Cannas can start to go out without protection. Similarly, after a period of hardening off, tender plants like squashes, peppers and tomatoes can go into your kitchen garden. By the end of May, the soil should be warm enough to sow beans straight into the ground too.

Potatoes are likely to be showing growing tips above ground by early May, so make sure that you draw soil over these new tips both to protect the tips from overnight cold and to make sure that you don’t get developing tubers exposed to light, which will turn them green and unusable.

Earthing up potatoes

Normally, the Chelsea Flower Show at the end of May signals “The Chelsea Chop” for late-flowering perennials (for example Phlox, Helenium, Echinacea and some Sedum). The show is later this year, but it is still a good idea to cut back these plants now by about half using shears. This will give you bushier, more compact plants and usually more flowers that will extend later into the season.

The foliage on spring bulbs should have died back by the end of May, so it is good time to clear away the dead foliage to create space for your summer plants. If flowering of daffodils has reduced over the years, then they may be congested. Now that they have returned to dormancy, you can lift and divide them, re-plant them nice and deep (about 3 times the depth of the bulb and if your drainage is poor, add some grit to the planting holes. If you have had bulbs in pots over the winter, then plant these out as well to increase numbers in the garden.

March saw the start of spring, and with longer days and warmer weather the garden begins to get growing. In particular, the grass will start growing more strongly now, so get your mowers ready. Keep the mower blades quite high to start with to avoid stressing the grass plants. A high nitrogen feed will also help to improve the overall quality of the sward. Many gardeners are now letting lawns grow longer and allowing more weeds/wildflowers (delete according to choice), so tidy according to your own preferences.

If you grow potatoes, then a good place to put your early batches of mown grass (provided it is free of herbicides) is in your prepared potato trenches. As the grass breaks down it helps the soil to retain moisture and creates slightly acidic conditions, which can protect against common scab.

One of the joys of spring is the re-emergence of herbaceous perennials. However, the succulent new foliage on plants like Hostas and Delphiniums is a delight for slugs and snails, so be ready with your preferred defence.

This is a great time to pay attention to herbaceous perennials generally. Cut back any dead growth to create space for this year’s shoots and if clumps are over-crowded or too big it is the perfect time to divide them. This is not a difficult job, lift the whole plant and cut the root ball into a number of smaller pieces, making sure that you’ve got both roots and shoots on each piece. A spade or an old saw are perfect tools for the job. Re-plant the selected divisions immediately and water in well. Also cut back semi-evergreen perennials such as Penstemons to a low framework of sturdy stems.

As plants get back into active growth, it is a good time to feed them, this applies to most plants, but is particularly relevant for permanent container planting where there is no natural renewal of nutrients.  Scrape away the top couple of cm of older compost, top dress with new compost with some slow release fertiliser mixed in.  We use a multi-purpose liquid feed for most established plants/containers.

The flowers on the earliest spring bulbs will have started to die off by now, so be sure to pinch off the dead heads so that the leaves feed the bulb for next year, rather than encouraging seed formation. Leave the foliage for 4-6 weeks after flowering to get as much photosynthesis as possible, again this will help to feed the bulbs.

In the vegetable garden you can get your early potatoes in the ground and spring sown planted onion and shallot sets can still go out. If you have a propagator, a greenhouse, or even a warm window ledge, you can sow tender fruiting vegetables (tomatoes, peppers, aubergines etc.). Don’t overwater seedlings, especially those of smaller plants to avoid the fungal diseases that cause “damping off” – which can quickly kill off most of the contents of a seed tray.

Finally, if you haven’t already done so, now is a good time to clean and disinfect used pots and greenhouses to prepare for the busy growing season ahead. You should remove all debris and wash with a mild solution of a disinfectant such as Jeyes Fluid. This will help to avoid fungal diseases such as dampening off, and get rid of any pests which have taken advantage of your hospitality over the winter.

This column was drafted in mid-January, a couple of weeks into the latest Covid lockdown and with the very grim news surrounding us, it is easy to overlook small sources of joy, such as gardens. However, we know that for many people time spent in their gardens, or other open spaces, last year helped to make life a bit brighter.

Lengthening days with more light and emerging snowdrops, crocus and daffodils not only tell us that another gardening year is beginning, but also provide flashes of cheer and the promise of a spring.

Crocus at the end of January

Despite the lengthening days and occasional warm spells, February is still winter and is often a wet month. So, as we usually advise at this time of year, don’t be in a hurry. If the ground is waterlogged or frozen, steer clear of lawns and borders – you could create more of a mess than you clear up.

Satisfying jobs are pruning apples, pears and wisterias. They should still be dormant and with no leaf cover it is much easier to see the shape you’re creating. You can easily distinguish the larger, flowering (and therefore fruiting) buds allowing you to produce a balance of new growth and flowers. As with all pruning, the first task is to remove the three D’s: Dead, Diseased and Damaged material. Then take out crossing branches that cause congestion and finally, cut back to the size and shape that you want.

Pruned Apple Tree

Pruned Pear Tree

Don’t forget to look around the garden to check for gaps where you might add seasonal colour like primulas (or indeed clumps from previous plantings that might now be ready for splitting).

For the kitchen garden, you can begin sowing summer cabbages, broad beans and beetroot under cover and if you haven’t done it yet, sow onions and leeks. You can also sow flowers and while warm windowsills may be a good place to start many seeds, don’t forget that you can start hardy annuals outside.

2021’s Leek seedlings

Finally, for soggy days when you’re stuck inside, spend some time cleaning and sharpening your tools. As well as extending their lives, using well maintained tools is much easier.

As these notes were written just after the start of our second national lockdown, it is probably appropriate to reflect again on how important those of us lucky enough to have them, have found our growing spaces over the past few months.

Gardening is by nature forward looking, so rather than thinking about winter jobs, let’s be optimistic and talk about investing time now for pleasure next year.

Take advantage of bright winter days to tidy up a bit, but as we suggested last month, don’t be over eager. Increasingly leaving things a bit less tidy is being recommended to provide winter food and shelter for wildlife.

Winter can require a bit of patience, avoid sodden or frozen ground as it is all too easy to compress it and ruin the soil structure at this time of year. If you find yourself frustrated and trapped indoors, relax with a cuppa and seed catalogues and look forward to the spring that is just around the corner!

A bit of judicious tidying of old and damaged foliage on Hellebores that will be starting to put up flower spikes in December and January will help to display the flowers to best effect.

Hellebore

Another Hellebore

Now is a good time to prune plants that “bleed” sap at other times of year such as grapevines, Acers and Betula.

We don’t often get heavy snowfall in this area, but if we do then try to clear snow from evergreen hedges as the excess weight can cause the plants to split.

Winter brassicas will be dropping older leaves and it is a good idea to tidy this up so that they don’t provide over-wintering sites for pests and diseases. If you have a heated greenhouse, then pests such as whitefly and mealy bugs will still be active, so watch out for these even through the winter.

Once you’re fed up with tidying and have ordered next year’s seeds, it is also a good time of year to get creative and increase your plant stocks by taking hardwood cuttings (for example roses) and root cuttings (Verbascum, Acanthus, Oriental Poppy, Japanese Anemone).

Most important of all, look after yourselves and stay safe.  2021 holds out the hope of better times ahead with Covid vaccines on the horizon, but there is still going to be a lot of hunkering down over the winter before we can all emerge into a brighter spring.

With short, dark days dominating, what could be better than looking forward to next spring by planting tulips? Plant them deep (three times the depth of the bulb) and if your ground is heavy, add some gravel to the bottom of the hole to aid drainage.  You might not reach the levels of drama of the Keukenhof gardens, but tulips are hard to beat for opulent flowers in late spring.

We are also in prime planting time for bare root trees and shrubs (and raspberry canes). Make a square hole 2-3 times the size of the rootball to a depth the same as the soil line on the stem add some mycorrhizal fungi and water in well.  a wide (and square) hole encourages the roots to spread out helping new plants to establish more quickly. This step-by-step guide from the RHS shows how straightforward the process can be.

Tidying up tends to be a popular theme this month, but let’s remember that there is increasing evidence that not being too tidy can help wildlife by providing food and shelter for invertebrates, birds and mammals. There are however some bits of tidying that it is worth doing, clear leaves from paths and lawns and if you have the space store them in leaf mould bins. In a couple of years you’ll have a really good soil conditioner. If you suffer from rose black spot, then collect up all the fallen leaves from the roses, but burn these leaves to avoid creating reservoirs for the disease. With the winters around here being quite mild in recent years, traditional practices like lifting dahlia tubers may no longer be necessary.

Trees grown for winter bark colour like Acer griseum and Betula utilis look even better if you wash the bark with a mild soapy water solution. While thinking about trees, if you have any that are staked, check that the stake is still sound and that the tie has not got too tight as the tree has grown over the summer.

In the vegetable garden, if you grow winter brassicas, make sure that they are netted or hungry pigeons will soon strip your crop.  This was one of our cages back in the spring.  You can see how tight the netting is, which not only makes sure that there are no gaps for pests to gain entry, but also means that birds or small mammals can’t get caught up in loose, flapping netting.

Brassica cage May 2020

October is a real month of transition, early in the month it can still feel like late summer, by the end we may well have had the first frosts and the hour has gone back. Tasks will therefore change as the month progresses. In early October, dead-heading Dahlias will prolong flowering, but by the end of the month you may be lifting the tubers for winter storage.

October is a good time to move established shrubs. The soil is warm, so roots will start to establish as soon as they are re-planted, but growth is slow, so there will be less stress on the plant. For deciduous shrubs it is best to wait until leaf fall is complete.

There is lots that can be done to prepare for next spring. Feeding and scarifying lawns will help them to overwinter in better condition. It is the perfect time to plant spring bulbs and hardy spring bedding –like primulas wallflowers and forget-me-nots. You can also sow sweet peas now for next summer’s display.

In the kitchen garden it is also a time for enjoying the fruits of this year, while preparing for next year. Harvest hard-skinned squashes and pumpkins before the first frosts ready for storage, putting boards under the ripening fruit helps to protect them from rotting if the soil gets damp. In our garage they are currently joined by potatoes, onions and garlic.

Storage of squashes, potatoes and onions

Our domestic “giant” pumpkin was hard fought, although neither of them were exactly giants, with the winner weighing in at a whisper under 30kg.

Pumpkin contest

Apply grease bands to minimise infestation by winter moths on apples and pears and for next year plant autumn sowing garlic and onion sets and they’ll get good root systems established before winter sets in.