Guide to Spring Gardening

Spring is the busiest time of the year in the garden. Sowing and planting, of many plants, are in full swing. But beware of the weather. Mild spells will encourage early growth and germination, which could be knocked back by a sudden cold snap. At this time of the year cloches and frames are invaluable.



If the soil is sufficiently dry make a start in sowing hardy annuals.

Gladiolus corms and ranunculus tubers can be planted if soil conditions are suitable; so, too, can hardy herbaceous perennials.

Dormant dahlia tubers can be planted at the end of the month.

Evergreen shrubs can be planted at the end of the month.

Roses should be pruned just as they are starting into growth.

Carry out lawn repairs before mowing starts.

Sow summer bedding plants in the greenhouse.

Prune shrubs that flower on new wood.


Apply and hoe-in a general-purpose fertilizer around all fruits. Give them a mulch, too.

As soon as the soil is in a suitable state, make a start with vegetable sowings.

Potatoes are planted at the end of the month.

If you have spring cabbages, give them a feed of high-nitrogen fertilizer to boost growth.

If the vegetable plot is still wet, put some cloches in place to help it dry out before sowing.



Sow hardy annuals outdoors and summer bed-ding plants under glass.

Continue to plant gladioli, dahlia tubers, herbaceous plants, summer-flowering bulbs, ever-green shrubs and conifers. Continue with weed control; weeds will be in full growth by now.

There is still time to carry out lawn repairs and this is a good time to sow a new lawn, apply lawn fertilizer, moss killer and weedkiller. Liquid feed spring bulbs after flowering. Apply mulches around all permanent plants such as roses and shrubs. Lawn mowing starts in earnest this month.


Spray fruits as necessary to control pests and diseases, but not when in flower.

Continue with vegetable sowings of all kinds.

Sow tomatoes in a greenhouse.

Thin out vegetables sown last month.

Earth up potatoes and plant maincrop varieties.

Support peas and tall broad beans.



At the end of May plant summer bedding plants in tubs and prepared flower beds.

Sow seeds of hardy herbaceous perennials, trees and shrubs, rock plants, spring bedding plants and summer-flowering biennials for next year.

Discard spring bedding plants after flowering.

Spring bulbs can be lifted and ‘heeled-in’ a spare piece of ground until the foliage has died down.

Chrysanthemum and dahlia plants can be set out (dahlias at the end of May).

Thin out hardy annuals if necessary.

Make a start on hedge trimming.

Water the lawn well in dry periods.


Plant out tomatoes at the end of May. Continue with vegetable sowings, including sprouting broccoli, cucumbers, kale, marrows and swedes.

Hoe regularly and water well in dry periods. Keep an eye open for pests and diseases. Plant tomatoes, capsicums, aubergines and cucumbers, in the greenhouse.


Spring is the main season for sowing and planting, but before you make a start ensure your soil is in good condition and contains adequate plant foods.


Plant foods are supplied by fertilizers, which are lightly forked into the soil before sowing or planting. Most plants need a general-purpose type containing the three major plant foods: nitrogen, which encourages growth of shoots and leaves; phosphorus, responsible for healthy root growth; and potash, which assists in flowering and fruit production.

One of the most widely used general-purpose fertilizers is Growmore, which is suitable for flowers, vegetables and fruits.

It is possible to buy fertilizers which supply only one plant food: for instance, sulphate of ammonia (nitrogen), superphosphate (phosphorus) and sulphate of potash (potassium), but these have to be mixed together or applied separately, which is more time-consuming. These so-called ‘straight’ fertilizers are useful, though, if the result of a soil test shows your garden to be deficient in only one or other of the major plant foods.

Soil-testing kits that enable you to test for plant nutrients and for acidity are available from garden centres and come complete with instructions. It is certainly a good idea to carry out a soil test before applying fertilizers as then you will know how much to apply and which particular foods are needed.

At this time of the year it is also recommended that you test the soil for lime content. Many plants need alkaline conditions; certain vegetables give best results in limy soil, notably potatoes and brassicas (cabbages, etc). Again, use a simple, inexpensive testing kit, and follow the instructions.

The degree of alkalinity or acidity is measured on the pH scale, which extends from zero at the acid end to 14 at the alkaline end. These extremes are never encountered in gardens, and few soils are below 5 or higher than 8. The neutral point is 7, but for a great many garden plants a pH of 6.5 (that is, slightly acid) is aimed for. For lime-loving plants, a little over 7 would be suitable. If you need to increase the lime content, use hydrated lime.

Established garden plants, such as shrubs, perennials, roses, hedges, and fruit trees and bushes, should also be fed at this time of year. Simply scatter a balanced fertilizer around these and lightly hoe or fork it into the top few inches of the soil. This is known as top-dressing. If the soil is dry, water it in. There are special fertilizers for some plants, such as roses.


Mulching is an important aspect of soil and plant care, yet how many people actually practise it? It involves placing a layer of organic matter around established plants, about 50mm (2in) deep. This layer should extend well over the root area -ideally it’s best to mulch an entire border or bed.

What does a mulch do? Firstly, it helps to supply the soil with essential humus which very much improves soil structure, particularly sandy, chalky, gravelly and clay types. Humus encourages beneficial organisms to build up in the soil, and helps to conserve moisture in dry weather and even to improve drainage in heavy soils. A mulch will help to prevent the growth of annual weeds and stop rapid loss of moisture during dry periods.

There are many materials that can be used for mulching. Farmyard manure, well rotted, is probably best for most plants. The next best is garden compost. They both supply valuable plant foods. Mulches which do not supply much in the way of foods include peat, pulverized or shredded bark, leafmould, mushroom compost and spent hops.

Apply a mulch only to completely weed-free soil, and only when the ground is moist. Remember it will not prevent the growth of perennial weeds.


It is vitally important to get weeds under control before sowing or planting, for they compete with plants for food, water and light – and if not controlled they generally win! It is more difficult to eradicate weeds once plants are growing. It is far better to rid the ground of them beforehand.


As far as gardeners are concerned, there are two types of weeds – annuals and perennials. The annuals germinate in the spring, grow to flowering size, set and scatter seeds and then die, all within one growing season. As they scatter thousands of seeds it is essential to destroy them before they flower. Perennial weeds live for several years and colonize the soil with deep roots and underground stems, or runners, which root into the soil and produce new plants. Roots and underground stems are generally difficult to remove by hand. If a piece of root or stem is left in the soil, it will grow into another plant.


Provided they are used as directed by the makers, chemicals represent the most efficient means of controlling weeds.

Annual weeds can be prevented from growing by applying weedkillers containing simazine or propachlor to weed-free soil. These can be used around cultivated plants. Paraquat will also kill annual weeds – it is applied when weeds are growing and can be used around cultivated plants, but keep it off them or they will be damaged or killed.

Weedkiller containing glyphosate will kill most perennials, and can be used around cultivated plants provided it does not come in contact with them. If there are only a few perennial weeds to deal with, use glyphosate as a ‘spot treatment’, dabbing individual weeds with a special applicator. If couch grass and other perennial grasses are a problem, use alloxydim-sodium, which can again be used with care around garden plants. Weedkillers which must be used only on vacant ground include dich-lobenil and, for tough woody weeds like brambles and bracken, a brushwood killer containing 2, 4-D and 2,4,5-T.


Hand removal is the alternative to chemicals. A small hand-fork, or onion hoe; a cultivator (the kind with three or five prongs); a draw hoe and a Dutch hoe all have their uses. The ideal method is to hoe out weeds while they are in the seedling stage, as it is more time-consuming to remove larger weeds. Carry out hoeing on a fine warm day so that the weed seedlings quickly shrivel and die.


Paths and other hard areas can be sprayed with special path weedkiller containing the chemicals paraquat, diquat, simazine and aminotriazole.


If you keep the soil completely covered with dense plant growth, few annual weeds will be able to grow. Generally, though, the more vigorous perennials will still emerge; and you will, in any case, need to keep the soil weed-free while the ground-cover plants are establishing themselves. There are many dense, low-growing plants that can be used as ground cover on banks or around larger plants such as shrubs.

Try the following: Cotoneaster dammeri, varieties of Euonymus fortunei; rose of Sharon (Hypericum calycinum); ivies such as the ‘Eva’, ‘Goldchild’ and ‘Goldheart’ varieties of Hedera helix; Pachysandra terminalis; the pig-a-back plant (Tohniea menziesii); Prunus laurocerasus ‘Zabeliana’; succulents such as Sedum spathulifoliam; and varieties of the periwinkle species Vinca major and V. minor. Prostrate junipers, such as Juniperus horizontalis and its varieties, are excellent, too.

Planting the Garden in Spring

Plants which grow from bulbs, corms and tubers provide an easy means of filling the garden with colour. One can virtually guarantee they will grow and produce plenty of blooms.

All need plenty of sun and a reasonably fertile, well-drained soil, which can be improved before planting by digging in peat and adding a slow-release fertilizer.


Dahlia, a range of subjects from dwarf bedding varieties to giants over 1.2m (4ft) tall. A vast range of colours is available. Plant 100-150mm (4-6in) deep and 450-900mm (18-36in) apart.

Begonia, invaluable for troughs, tubs and summer bedding. Grows 150-250mm (6-10in) in height, bearing brilliantly coloured flowers.

Gladiolus, handsome spikes of flowers in many colours. They are ideal for cutting. Plant 100mm (4in) deep and 150-200mm (6-8in) apart.

Anemone ‘De Caen’ and ‘St Brigid’ varieties are available in various colours. Plant 50-75mm (2-3in) deep and 150mm (6in) apart each way.

Galtonia candicans, the white summer hyacinth. Plant 150mm (6in) deep and 300mm (12in) apart.

Ranunculus, good cut flowers in a variety of colours. Plant 50-75mm (2-3in) deep and 100- 150mm (4-6in) apart.

Tigridia, the brightly coloured tiger flower.

Plant 75mm (3in) deep and 150mm (6in) apart.


Otherwise known as herbaceous plants, these are excellent value for money as they live for many years if well looked after. Prepare the ground as for bulbs.

Most need a sunny spot. Popular plants are achilleas, aquilegia, asters or Michaelmas daisies (autumn flowering), Chinese lanterns, coreopsis, delphiniums, erigerons, gaillardias, geums, gypsophila, heleniums, irises, lupins, oriental poppies, phlox, pyrethrum, rudbeckias, scabious and solidago (golden rod).

For shade try alchemilla, dicentra, epimediums, hardy geraniums, hemerocallis (day lilies), hostas (plantain lilies), and tradescantia.

Planting is easy if you buy plants in containers from a garden centre – take out a hole slightly larger than the rootball and of such a depth that the ‘crowns’ of the plants (where the stems join the roots) are at soil level. Firm in well and keep watered in dry spells.


These provide a cheap and very colourful display in summer. Seeds are sown in spring, ideally in bold patches – one for each variety.

Pick a spot in full sun for best results. Before sowing, mark out the patches and then in each one make shallow parallel furrows with a pointed stick, about 150mm (6in) apart, in which to sow the seeds. The top ten:

1. Alyssum – white or pink flowers, for edging

2. Calendula (pot marigold) – orange, yellow flowers

3. Candytuft – dwarf, mixed colours

4. Clarkia – tall, double flowers, mixture of colours

5. Cornflower – tall or dwarf, blue flowers

6. Eschscholzia – dwarf, bright poppy flowers

7. Godetia – tall or dwarf, poppy-like blooms

8. Larkspur – tall, annual delphinium, many colours

9. Nasturtium – dwarf or climbing, brilliantly coloured

10. Nigella – medium grower, ferny foliage, mixture of colours


Evergreen shrubs, trees and conifers can be planted in spring as well as autumn. They are supplied in containers so all you need do is take out an adequate planting hole for the rootball, and ensure its top is slightly below soil level when planting.


Add a proprietary evergreen, planting mixture to the planting hole, and to the backfilling soil. Keep well watered throughout the spring and summer if the weather is dry. For the first six weeks after planting, spray the foliage daily with plain water (unless it is raining). Alternatively, use a proprietary anti-transpirant spray, available from garden centres (see also pages 54-5).


If you have a heated greenhouse, try raising your own summer bedding plants such as French and African marigolds (Tagetes), busy-lizzie (Impatiens), monkey-flower (Mimulus), zinnias, petunias, ageratum, alyssum (Lobularia), tobacco plant (Nicotiana), verbena, and Phlox drummondii. These are the easy ones.

You should use a heated propagating case, as the seeds need a temperature of 18-21°C (65-70°F) to germinate.


When planting summer bedding plants in containers, such as tubs, hanging baskets and window boxes, put in plenty of plants to create an impression of bountifulness as quickly as possible. Use plants of at least two different heights as well as trailing subjects around the edge to produce the greatest area of colour.

Good plants for the edges are trailing lobelia, impatiens, ivy-leaved geraniums (Pelargonium x hortorum), trailing fuchsias, black-eyed susan (Thunbergia alata), and petunias.

Next should come short plants such as dwarf French marigolds, bushy lobelia, and dwarf fibrous-rooted begonias, building up to a taller plant or two; use zonal pelargoniums (Pelargonium zonale), bush fuchsias, compact African marigolds, or cherry pie (Heliotropium).

There will be stiff competition between container-grown plants so start off with a rich compost, and one that will not dry out too quickly. Use John Innes potting compost No. 2 or a similar proprietary compost.

The first step with containers such as tubs and window boxes is to make sure the drainage holes in the base are clear. Cover them with pieces of broken clay pot or tile, and cover these in turn with a 25-50mm (1-2in) layer of coarse shingle before filling to within 100mm (4in) of the rim with firmed compost. Start planting in the centre, working out to the edges. Add more compost around the roots as you plant, so the final compost level is 25-40mm (1 – 1-1/2in) below the rim of the container.

Wire hanging baskets must be lined with sphagnum moss or a proprietary compressed peat liner to hold in the compost. Alternatively, you could use polythene sheeting, first making some drainage holes in it.

Containers must be checked daily for water requirements – in hot weather they may need watering twice daily.


Ageratum. Popular dwarf bushy plants in shades of blue, purple and lilac. Alyssum is ideal for edges of containers. White or variously coloured flowers. Antirrhinum. Choose the dwarf bedding varieties of snapdragon for containers. Many colours are available.

Begonia semperflorens. The fibrous-rooted bedding begonia comes in many colours, from white to red and pink. The leaves may be green or bronze.

Campanula isophylla. Generally thought of as a houseplant, this blue or white bellflower can be grown outside in summer.

Coleus. The flame nettle, most usually grown as a greenhouse pot plant, is nevertheless excellent for foliage colour in outdoor containers.

Fuchsia hybrids. There are many varieties to choose from, either bushy and upright or pendulous. The latter are ideal for baskets.

Heliotropium. The heliotrope has fragrant flowers in shades of blue or violet.

Impatiens. The bedding type of busy-lizzie is an ideal plant for shade. Many attractive colours are available.

Lobelia. Blue lobelia (other colours are also available) in trailing or bush form is indispensable for containers.

Pelargonium. Use the zonal varieties for the centres of containers and the ivy-leaf kinds for the edges and for hanging baskets.

Petunia. Excellent for window boxes and hanging baskets. Choose the small-flowered ones as they have better weather resistance than the large-flowered type. There are many different colours.

Salvia splendens. If you want bright red blooms on short plants, then salvias are the answer. Purple, salmon and white varieties are also available.

Tagetes. Dwarf French marigolds are best for edging. Use the taller African type for the centres of boxes and tubs.

Verbena. Trailing verbena, available in many colours, is ideal for baskets and the edges of boxes and tubs.

12. August 2013 by admin
Categories: Featured, Garden Management, Top Tips | Comments Off on Guide to Spring Gardening


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