Herbaceous and border plants

 HERBACEOUS AND BORDER PLANTS

The garden border has evolved over many years as the place around the house to grow herbs for culinary use, flowers to cut for the home and grow a few colourful favourite plants. Plant explorers brought back new plants to try out and slowly the variety of border plants increased in range. These  can include shrubs, roses, herbaceous plants, bulbs, climbers, ground cover, and anything else that happens to be popular at the time. Often in the early years before plants get established any bare patches can be filled with bedding plants and annuals from seed sown each year.

Borders next to buildings are often designed to link the hard building structure into a soft landscape, but with minimal maintenance in mind. Evergreen ground cover including conifers, are favourite and if the ground is on a slope choose plants that can bind the soil surface to prevent erosion such as flag Iris and Shasta daisies.

Design

Borders are usually long and narrow to be viewed from the front with a solid and usually permanent backing. This may be the house wall, a fence or hedge. Although it is natural to have the taller plants at the rear and short ones at the front, try to vary this to give variety of height.

Each plant will have its own season from the Doronicums and Pulmonaria flowering in early April, Delphiniums in mid summer, to the Michaelmas Daisies in September and October. It is better to try and group plants together in their season to increase the impact, and choose plants that blend well together by height, variety of foliage shape or colour. Good combinations include flag Iris with Oriental Poppies and Pyrethrum, try day lilies with Lavender in adjacent drifts, Delphiniums and Phlox are excellent together for height and colour and at the end of the summer into autumn try Anemone Honorine Jobert with a range of Asters, (Michaelmas daisies). At ground cover height, the black grass Ophiopogon is dense enough to smother weeds and when underplanted with white snowdrops is the perfect combination for late winter.

Where ever a plant is a late starter, under plant it with early flowering bulbs such as snowdrops or crocus. Plants that have a very short season such as Pulmonaria can be mixed with Cyclamen hederifolium which begins to grow and flower in late summer and then retains its foliage all winter.

If the border is in shade or partial shade select appropriate plants such as colombines, (Aquilegia), Hostas, Trilliums, Meconopsis, Epimedium, and Primulas, Bergenia, Lamium and Persicaria for ground cover.

If the border is free standing and is not backed by a building, a hedge at the back can help to define its shape, give shelter from strong winds, add colour and give a green background to the plants when in flower.

If the back of the border is a wall or fence it could create an ideal spot for a climber to give added height.

Soil preparation and planting

Borders are often planted up in the autumn so ground preparation is normal in late summer. If the soil needs a lot of amelioration, add a fair bit of garden compost, dig it in then sow a crop of mustard in spring. Dig it in when it comes into flower but before it sets seeds.  Allow it about a month before planting so the mustard is beginning to rot down and open up the soil. Make sure the soil is firmed and raked level and water if necessary before planting. Water again after planting.

Order plants well in advance as often the more popular ones sell out quickly. Your local garden centres will stock most of your needs, but it may be necessary to go to specialist growers for the best varieties. Blackmore and Langdon in Bath specialise in Delphiniums, Phlox and Aquilegia, and Claire Austin in Shropshire specialises in hardy plants. She has some terrific varieties of flag Iris, Daylilies and Oriental Poppies. They both have websites.

Most plants display best when planted in bold drifts.

 

Border plants

These tend to be lower growing than the majority of herbaceous plants, and may not die down in winter such as border carnations and Pinks, Lavender, Rosemary, Kniphofia, Sedum and Bergenia.

They add interest in the winter months when other herbaceous plants are dormant and have died back to ground level. Many rock garden plants can be added to the front of borders to soften edges such as the Delosperma, a succulent sun loving plant packed with yellow flowers in May and grows quickly, though no higher than three inches.

Flag Iris have always been my favourite. They are so easy to grow and come in some fantastic colours, though you need to buy from the specialists to see a good range. Daylilies also have a wide range of fantastic colours that will brighten up any border.

Herbaceous plants

True herbaceous plants die down in winter, but they can grow very fast and there is always something in flower from April till the frosts come the following winter.

My season starts with the blue Pulmonaria and yellow Doronicums in April, then the Himalayan blue poppies and Euphorbias in late April or early May.

Soon there is a rush as the Peonies, Pyrethrums, flag Iris, Colombines, Campanulas, and Oriental poppies enjoy the warm weather.

As they finish, the summer flowers take centre stage with Phlox, Delphiniums, Daylilies and Geraniums.

Autumn is the time for the Michaelmas daisies, Agapanthus, Kniphofia and Anemone Honorine Jobert. Most of these plants need to be in a large group to have full impact.

Bulbs

Spring flowering snowdrops, aconites and crocus are perfect in any spare space, and even narcissus, tulips and hyacinths can be found a spot. Many drifts of low growing plants will not mind a few summer flowering lilies planted at their feet.

Maintenance

Wherever possible I tend to only grow those plants than can stand up without needing support, but some essential types such as the Delphiniums will require staking. Weeds are usually only a problem early on as once the plants grow they will soon smother out any weeds.

After three or four years some clumps will require dividing and replanting.

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Too big for your roots

LOOKING AHEAD WITH SEASONAL TASKS

To keep the garden looking good all year round it is not enough to put in the hard graft without a fair bit of planning ahead. Tasks performed now will ensure the garden continues to look good next spring and summer.

My past career in horticulture has taken me all round the UK so I have had numerous gardens to design, plant and care for. I don't rush into the task but consider carefully all the different elements I want to incorporate into the garden. I may want flower beds, roses, heather garden, herbaceous border, annual border, flowering shrubs, garden trees, climbers, vegetables and fruit and most likely a greenhouse and sunny sheltered patio.

Shasta daisies

Initial garden design

Nearly all existing gardens have some redeeming elements that are worth preserving, then give a lot of thought to what parts get the most sun, shade and shelter and the need for paths.

Often there is a need for privacy with a sunny patio to relax on, steep banks to stabilise and shelter from wind may be needed. 
If some trees, appropriate to the size of the garden, can also be planted it will give the garden scale and a backdrop within which to set out the different elements.

All of these features need to be thought out at the beginning to save moving plants around later on, but don't worry if things do not go quite as planned. That is quite normal, but make sure you have the best place for your sunny patio to relax on with a wee drink (non alcoholic, of course) while doing all this planning.

Every time you visit a garden centre you are likely to come away with that special plant that needs fitting into this great design and that's when problems begin, or you often find that you want more plants than the garden can hold. Also many plants get too big for the space you thought was sufficient for them. It is sorting out these continual problems that makes gardening a year round affair.

Seasonal tasks

Now is the time to tackle some of those tasks.

Flag Iris

Flag Iris

This is a good time to split up flag Iris when the clumps have grown large and flowering starts to deteriorate. There is always strong young rhizomes around the outside of big clumps that can be dug out for replacing. Flag Iris like a sunny position with good but free draining soil and do not plant too deep as the rhizomes grow on the surface of the soil.

Lavender

Another plant I grow in a fairly dry border is a large drift of Lavender. It started off as an informal planting ten years ago of about twenty plants that eventually merged into a bold sweeping group. Very impressive at flowering time but now a bit sprawling even though they have been regularly pruned every year after flowering.

I will take a batch of cuttings about six to eight inches long and put them into a shallow tray of free draining compost kept in a shady sheltered spot outdoors. They usually root very easy and will be ready to pot up in late autumn then overwintered before planting back into a drift in spring. The old drift of Lavender will be dug out and the ground dug over, working in plenty of garden compost.. 

Lavander and heather cuttings

Heathers

A similar situation has arisen in my heather garden where a large drift of gold and bronze Calluna vulgaris has got too straggly. However these require different treatment for propagation by cuttings. I will take strong young shoots about two to three inches long and space them out about an inch apart in shallow tray in normal seed compost which will then go into a covered propagator with bottom heat. This will retain moisture to keep the cuttings sturdy. They should be ready for potting up by the end of autumn or sooner, and again these will be planted out in late winter or early spring.

Heathers can remain in great shape if they are trimmed over with garden shears after flowering, but do not cut into the old wood otherwise they may not recover. However the Irish heath Daboecia will grow again very easily when severely chopped back into old wood after flowering.

Poppies

Another plant that needs looking after is the Himalayan blue poppy. These give a fantastic display as a woodland edge plant when in a large informal drift. The plants will flower themselves to death over the years so new plants must be propagated from seed saved from the drift. I leave some seedheads to mature after flowering but remove them in July.

Let them dry off before shaking out masses of seeds. These can be sown in trays and left outdoors in a shady spot over winter, but do not let them dry out and protect them from birds who may dig up the compost. They require a cold period for a decent germination so provided the winter is fairly normal this should be ok and provide you with numerous young seedlings in spring. It is usually another year before they are big enough to flower.

Poppies come in numerous types as annuals, e.g. Californian, Ladybird, and biennials e.g. Iceland and perennials, e.g. Meconopsis and Orientals.

It is the biennial Iceland poppy that can be sown now from seed saved from those that have flowered from early spring and continue to provide a fair bit of bright colour.

I sow mine in plug trays with seed compost and keep them in a warm but shady position and make sure they never dry out. Hopefully they will germinate and get potted up in late summer to produce plants for planting in autumn or spring.

Iceland poppies can also be sown direct into the soil in August or September and will overwinter as young seedlings ready to flower in spring.

Feed the topsoil

To get the best out of all your plants you should make sure your soil is in excellent condition. Winter digging as early as possible and leaving the surface rough lets the weather break down the surface, and this is the best time to incorporate garden compost, manure or any other organic material to hand, even old growbags. This will improve drainage, warm up the soil, and increase microbial and worm activity which enhances availability of nutrients.

Every good garden should retain all waste plant materials for adding to the compost heap. I add grass cuttings, leaves, kitchen waste, shredded paper, and even tree and shrub prunings that first go through a shredder. Only things to get rejected are perennial weeds and any diseased plants. Good compost can also be used as a mulch on plants with surface roots that do not like soil disturbance, e.g. Azaleas, heathers

At this time of year waste from harvesting crops provides ample material to compost and it is a great idea to turn over the compost heap to allow even decomposition. It is hard work, but an excellent exercise with great benefits for all.

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