Maintaining The Vision

As a garden designer one of the questions I always ask clients when taking a brief is what their intentions are for the maintenance of a new garden. Are they going to maintain it themselves or are they planning to get a professional gardener to help? In either case, how many hours a week do they envisage will be spent looking after their outdoor haven?

Unlike interior design, gardens are not static. When the contractors and I leave the site at the end of the project and the garden is ‘finished’, it is only really the beginning. If left alone things will not just stay quietly as they are, small and neat and tidy. Nature has other ideas. Plants grow, and need watering and pruning etc and weeds will quickly avail themselves of the spaces between the new plants and thrive. Without regular care and attention the new garden will struggle to achieve it’s full potential.

I regularly write detailed, individualised maintenance plans for clients to enable them, and/or their gardeners to keep things looking good. I thought it might also be useful to produce a general guide to the care of the shrubs and perennials that I most often use. It will not include every plant in the garden but hopefully it will be helpful. There is also a monthly maintenance memo as a guide of what to do when during the year. These are based on what I do in my own garden and what works for me. Different people have varying ideas on when and how to do things. So use it or ignore it as you choose.

January: Monthly Maintenance Memo


Midwinter Fire’, ‘Kesselringii’ etc. Cut down to ground level about a third of the existing stems. Choose the oldest stems to remove. These will be replaced by new, vigorous, brightly coloured stems in the coming year.

Hydrangea arborescens ‘Annabelle’ can be pruned down to a pair of buds about six inches from ground level anytime from the end of November to the end of February. This is better done sooner rather than later if underplanted with snowdrops, cyclamen coum or narcissi.

Hellebore orientalis leaves should ideally have been cut down in December. Flower buds will start to emerge this month. Perennials and deciduous grasses left standing from last summer/autumn can be cut down anytime from now till the end of February. Leave Penstemon until April.

Roses, climbing and bush roses should be pruned now.

Enjoy the scent of Sarcococca, Mahonia, Lonicera x purpusii ‘Winter Beauty’ and Viburnum x bodnantense ‘Dawn’.

Snowdrops are starting to emerge. Punus subhirtella ‘Autumnalis’ will display blossom sporadically on milder days.

February: Monthly Maintenance Memo


Epimedium leaves can be removed now. Cut the existing foliage to the ground and by the end of the month or early March the flowers will start to emerge followed shortly by the new leaves. It can be risky to leave this job any later than mid February otherwise it is easy to cut off the delicate flowers with the old foliage.

Cut down any deciduous grasses by the end of the month. Evergreen grasses such as Stipa gigantea should have the old flowered stems only removed.

Prune summer flowering clematis back to a pair of buds about 50cms from the ground.

Buy snowdrops in the green, either Galanthus nivalis or Galanthus Flora Pleno by the hundred, or special ones singly. It’s also a good time to add Cyclamen coum to the garden as you can chose the flower colour and the leaf patterning of individual plants. Plant them at the same depth as they are in their pots, don’t be tempted to bury them too deeply.

March: Monthly Maintenance Memo


On established plants of Hydrangea paniculata, prune back last years growth to a pair of strong buds. Leave plants in their first couple of years alone.

Shorten stems on buddleja to a pair of strong buds about 50 – 70cms from the ground. It flowers on new growth.

If you grow Eucalyptus gunni for it’s foliage for flower arranging, now is the time to pollard it at a height that is convenient for cutting.

Cut back and tidy any herbaceous perennials still carrying last years growth. Penstemon can be cut back at the end of the month but preferably left for a few more weeks.

Towards the end of the month and into April remove the flowered stems of Helleborus orientalis as they go over and start to form seedheads.

Buy rose food and apply as they come into leaf, according to the manufacturers instructions.

Growth will start to happen as the weather warms up, the downside being, so do the weeds.

April: Monthly Maintenance Memo


Weed like mad. This is the time of year when annual weeds such as bittercress burst into action. Get them out now otherwise they can quickly become a real nuisance. If anything more sinister such as ground elder or bindweed appears, zap it with ‘Round up’ promptly. Weeding can be a bit of a slog at this time of year particularly with a young garden where the plants are smaller. But by the end of May there is usually enough new growth to diminish the opportunities for weeds and things calm down.

As narcissi and other spring bulbs fade, remove spent flower heads but leave the foliage to die down naturally.

Some paeonies have large heavy heads when in full bloom which can be easily damaged in heavy rain or strong winds. So with the double flowering types in particular it might be wise to stake them. It is best done now so that the plants grow up through the support and conceal the framework as they go. This should prevent the plant collapsing later. Single flowered paeonies have lighter heads and usually do not need support.

May: Monthly Maintenance Memo


Late tulips should be looking good now. Once the flowers fade remove spent heads but leave the foliage to die down and dry
out before removing this too. (Approximately 6 weeks from flowering).

Keep weeding but hopefully by the end of the month the ground will become covered with the newly emerging foliage of perennials and deciduous shrubs and the weeds will have less opportunity for action. Re zap any ground elder or bindweed with ‘Round Up’, it often takes two or three applications to deal effectively with these toughies.

Towards the end of the month box can be clipped. Choose a dull cloudy day so that the newly cut surfaces don’t scorch. Clear up all the clippings really thoroughly to prevent the opportunity for box blight to appear.

Tie in new growth on clematis and climbing roses.

Check tree ties which may be tight as the girth of the trunk increases, either loosen or remove if the tree is reasonably established.

Plant up pots/ containers for summer.

Visit the Chelsea Flower Show.

June: Monthly Maintenance Memo


Deadhead spring flowering perennials such as pulmonaria and aquilegia.

Cut down remove faded foliage from bulbs, which should be dried and brown by now.

Deadhead roses as petals fall. This encourages further flowering.

Cut lupins and delphiniums to ground level as the flowers fade. Mine will often rebloom later in the summer if axed now.

Water any new young plants as required if weather is hot.

July: Monthly Maintenance Memo


The garden should be looking wonderful now.

Keep deadheading and give roses a second feed at the beginning of this month to encourage them to produce a second flush of flowers.

Trim coniferous hedges.

Leave spent flower spikes of foxgloves intact if you want more plants. As the summer progresses the seeds contained within
the spent spike will ripen and when it has become dried looking you can sprinkle the seeds where you would like foxgloves in future and they will germinate very easily in early autumn.

Keep new plants watered especially young trees, hedges and hydrangeas.

Keep an eye out for any persistent trouble maker weeds and either dig them out or apply ‘Round Up’.

August: Monthly Maintenance Memo


Although it might seem strange to consider next spring at the height of summer, bulb catalogues are sent out at this time of year and ideally a bulb order should be made at the end of August or by early September. This is because narcissi need to be planted in September as they start to grow roots early in autumn. Alliums and tulips can wait to be planted until October and November respectively as their growth starts later. If you order early you are also likely to get the best choice before the most popular varieties of bulbs sell out.

Keep deadheading.

Trim yew hedges now.

Trim lavender after the flowers have faded. Remove flowered stems and use shears to reduce the plants slightly to a neat bushy shape.

If your foxglove spires have dried to a brown colour now is the time to carefully cut them down and shake the seed out where you would like foxgloves next year.

September: Monthly Maintenance Memo


If the weather is kind summer can continue well into September. Asters, echinaceas, verbena bonariensis, and dahlias should still be going strong, as will some roses.

Grasses really start to come into their own this month, particularly the later ones such as Panicum and Pennisetum.

Hopefully your bulb order will arrive and the priority is to plant the narcissi first. The bulbs need to be planted 2-3 times their own depth as a rule of thumb,15-20cms deep in the case of narcissi to ensure reflowering in years to come. They look best planted in informal groups or alternatively scatter them and plant them where they fall. Keep the rest of the bulbs in a cool, dark, dry place until you are ready to plant them.

October: Monthly Maintenance Memo


Rake up fallen leaves. If there aren’t many put them on the compost heap. If you have a lot it’s worth creating a separate pile and making leaf mould which is a very valuable soil conditioner.

Clear and cut down early summer flowering perennials such as astrantias, paeonies etc which will be looking tatty by now. Other perennials with attractive seedheads can be left to stand for the winter or cut down anytime between now and February.

Once frost has hit dahlias cut down the top growth and mulch to protect them during the winter. Most will survive with this treatment.

Plant allium bulbs and lilies. Same depth guide of 2-3 times the depth of the bulb applies.

Prune climbing roses and tie in before autumn gales arrive. Pick up and dispose of any rose leaves carefully. Do not compost these as they may harbour black spot and other diseases.

November: Monthly Maintenance Memo


Plant tulips, 10-15cms deep.

Continue to gather up fallen leaves.

Check tree ties and stakes.

Cutting down of old growth can continue as the weather allows
or be left till later in the winter

December: Monthly Maintenance Memo


Cut down to ground level and remove all old foliage from Hellebore orientalis. Do not put it on the compost heap. Doing this helps stops the spread of hellebore black spot and also allows the flowers to be seen when they emerge next month.

Guide For Pruning Shrubs

Group Recommendation
1 This applies mainly to evergreens. No pruning is required apart from light shaping and the removal of dead and diseased wood, or of wood damaged by frost. This can be done as soon as it is noticed. Shaping is best done in the late Spring or in August, but not after this otherwise the young growth will not ripen before Winter.
2 This group of plants flowers in Spring on old wood produced the previous season, so prune after flowering. Remove old wood which has borne flowers, retaining most of the young wood which will ripen later in the season and produce flowers the following year.
3 This group flowers in early Summer on both young and old wood, so prune after flowering. Each year, completely remove one or two old stems, easily identified by their greyish bark from the brown bark of the young wood. Also cut back flowering shoots to fresh growth on the main branches. Thin crowded shoots and remove weak twigs.
4 This group flowers in Summer and Autumn on wood produced in the current season. In early Spring, cut back to within two or three buds of the old wood. Also in this group are shrubs grown for the Winter interest of their coloured stems. The best colour is on the young wood so these should be pruned hard in a systematic rotation every second or third year.
Shrub Group/Pruning Recommendation
Abelia x grandilora Group 1
Artemesia Trim to shape, quite hard in spring.
Buddleja Group 4
Chaenomeles Group 2
Choisya Group 1. Do as little as possible for the first two years. After the first year it can be trimmed as a hedge in late May if this is the intention.
Cistus Group 1
Convolvulus cnerorum Trim to tidy in spring.
Cornus Group 4
Cotinus Group 4 but leave alone for the first few years.
Daphne Best left alone.
Deutzia Once established, cut out some of the old wood close to the ground after flowering.
Eucalyptus gunni Group 4. Coppice in early spring if grown for foliage to be used in flower arranging.
Euonymus ‘Emerald Gaiety’ Group 4
Fatsia japonica Group 1. Little or nothing is best.
Fucshia (hardy) Group 4
Garrya elliptica Group 1
Hamamelis Best left alone. Group 1 if you must.
Hebe Group 1
Hydrangea ‘Annabelle’ Either leave flower heads and stems to stand during winter and then cut all stems to two or three buds from base. Group 4. Or cut to similar buds in early winter.
Hydrangea paniculata Leave to establish for first two years, then Group 3.
Hydrangea macrophylla Prune back any weak growth immediately after flowering but leave old flower heads during winter to protect buds. Remove in March.
Hypericum Generally Group 1 but can be given the Group 4 treatment every few years to revitalize.
Ilex Group 1
Laurua nobilis Group 1. Trim to shape in April and/or August.
Lavandula Trim back to a neat shape with shears after flowering. Lightly reshape in April.
Leycesteria Formosa x Trim back to a neat shape with shears after flowering. Lightly reshape in April.
Lotus hirstus Shape and remove any damaged stems in April.
Mahonia Group 1
Myrtus Group 1 but can be clipped into quite a defined shape.
Osmanthus Group 1 but Osmanthus x burkwoodii can be clipped into a hedge. Trim to shape after flowering.
Perovskia ‘Blue Spire’ Group 4
Pholadelphus Group 3
Phormium Remove any dead leaves in spring but otherwise leave alone.
Photinia Trim to keep shape if necessary.
Physocarpus Group 4
Pittosporum Group 1
Potentilla Young plants can be pruned hard each spring to maintain good shape and vigour. On older plants remove only dead or damaged branches.
Pyracantha Group 1
Rhamnus Group 1
Ribes Group 1
Rosmarinus Group 2
Rubus cockburnianus Cut old stems down to ground level in February.
Salvia purpurescens Trim to shape in spring. Remove any damaged growth.
Sambucus nigra Do nothing for the first couple of years then cut back quite hard as required. Group 4.
Santolina Cut back hard in April. Tidy and remove spent flower stems after flowering.
Sarcococca Group 1
Skimmia Best left alone. Group 1.
Teucrium Trim to shape as required. Group 3.
Viburnum x bodnantense Group 1 but best left alone.
Viburnum tinus Group 1 but can be trimmed to a loose hedge.
Viburnum davidii Group 1
Vinca Group 1 Tidy as required.

Simple Guide To The Care Of Perennials

Perennial Care Recommendation
Achellia Cut all growth to the ground in autumn.
Agapanthus Remove old growth in either winter or early spring. The old foliage will go sludgy after a hard frost but left in situ it helps to protect the crown of the plant.
Alchemilla mollis Deadhead after flowering. Tidy in spring.
Anenome x hybrida Remove old growth in late autumn.
Aquilegia Cut out old stems after petals drop. Remove old foliage in autumn.
Aster Cut down in either late autumn or late winter.
Astrantia Deadhead after flowering. Cut all stems to the ground in autumn.
Bergenia Tidy up in spring, pulling out any old black leaves.
Brunnera Deadhead after flowering cut down old foliage in late autumn.
Centrantus ruber Remove spent flowerheads promptly or you will be over run with them! Cut down in late winter.
Cephalaria Cut to ground level in late autumn.
Cirsium Remove spent flower stems promptly and you may get a second flush of flowers. Cut down in late autumn.
Convallaria Nothing.
Crocosmia Remove all growth in late autumn.
Cyclamen Nothing.
Dahlia Remove all growth after frost. Mulch with compost to protect and feed.
Dianthus Deadhead and tidy as necessary.
Dicentra Foliage dies down naturally in early autumn. Remove then.
Digitalis There are lots of seeds in the old flower stem. When ripe cut down and scatter where you want them. Leave the basal rosette if it looks green and vigorous, it may flower again next year. Otherwise remove.
Echinacea As the flowers fade in the autumn leave the seed heads to stand during the winter. Birds love the seeds. Cut down in February.
Echinops Cut down in late autumn or winter.
Epimedium Remove the old foliage at the end of January. Flowers will soon appear followed by new foliage. Don’t leave this too late to do otherwise it is easy to cut off the emerging flowers with the old leaves.
Erigeron In mild winters it can remain evergreen so just tidy up in spring. Otherwise remove all old growth in spring.
Eryngium Remove old growth in late autumn.
Euphorbia Remove spent flower stems in late spring and any others which are dead or damaged. Wear gloves and old clothes as the milky sap stains and is a skin irritant.
Festuca Tidy up in spring.
Foeniculum Cut all old stems to the ground in February.
Galanthus Nothing, just enjoy.
Galium odoratum Tidy up in March.
Gaura Cut down to about 15cm from ground in late autumn or early spring.
Geranium Remove old growth in late autumn or winter.
Geum Deadhead and tidy as necessary.
Hakonechloa Remove old foliage at end of February.
Helenium Cut to the ground in late autumn or winter.
Helleborus Remove all old foliage in December. Remove flowered stems as seedheads form.
Heuchera Tidy as necessary.
Hosta Clear old foliage as it dies down in November.
Iris Old flower stems can be removed after flowering. Remove any dying foliage in autumn.
Knautia Clear old growth in November.
Lamium. Tidy as necessary.
Libertia Remove spent flower stems after flowering. Tidy and cut out any old or dead foliage in spring.
Liriope Deadhead after flowering. Tidy occasionally.
Lupinus Deadhead after flowering. Remove all old growth in late autumn.
Macleaya Remove all growth in late autumn or winter.
Miscanthus Cut down to about 15cms in late February.
Monarda Remove all old growth in late autumn.
Nepeta Cut back after flowering and again in late autumn.
Ophiopogon Nothing.
Origanum Remove spent flower stems in autumn or winter.
Osteospermum In mild winters it may stay green in which case tidy in spring. In hard winters cut back in spring.
Paeonia Deadhead after flowering. Cut down in autumn.
Penstemon Do not cut down in autumn. Tidy up and cut back as necessary in spring.
Perovskia Cut all stems down to 15-20cms from the ground in late February.
Phlomis tuberosa Cut down in late autumn.
Persicaria Cut down in late autumn.
Phlox Cut down in late autumn.
Polygonatum Remove all growth in autumn.
Pulmonaria Deadhead after flowering and tidy up as necessary.
Rudbeckia Leave to stand during the winter. Cut to the ground in February.
Salvia Cut down in late autumn or winter.
Sedum Leave seedheads to stand for the winter. Cut down in February.
Stachys Remove flowered stems and any damaged or untidy growth. Otherwise leave alone.
Stipa gigantean Remove old flowered stems in February. Leave main body of grass.
Stipa tenuissima Finger groom in late winter. Use gloves.
Tellima Deadhead after flowering.
Thalictrum Cut to the ground in late autumn or winter.
Verbena Cut down to 20cms from the ground in late autumn or early spring.
Veronicastrum Can be left to stand for the winter and cut down in February or cut to the ground in late autumn.
Viola Nothing