The BLOOMING GARDEN

Get to know the different plant categories

Annuals 

Last month we briefly introduced you to the different categories of plants that we all have to choose from as we try to work out what we want to grow in our gardens and, as promised we now start to expand that basic information.  Probably one of the first groups of plants that we were introduced to as children is the easy-to-grow annuals in their different combinations.  In the flower garden it includes some of the most beautiful and undoubtedly the most easily grown of all those things which make up a typical English garden. 

Annuals set the garden ablaze from early summer until autumn and earn their keep many times over during their short lives.  All annuals are characterized by completing their life cycle within a twelve month period.  They germinate, grow, flower and produce seed all during the favourable growing period.  They may only live for one year, but they are not difficult plants to grow if they are sown and planted at the right time.  These undemanding plants, ask only a place in the sun and to be watered during periods of dry weather. 

The different types of Annuals 

Hardy annuals are capable of withstanding frost and are generally sown outdoors in the place where they are intended to flower. Half-hardy annuals of which many are sold as bedding plants, are raised in warmth and not moved outdoors until the danger of frost is over, whereas the tender annuals although generally requiring constant greenhouse cultivation can safely be placed outdoors at the height of summer when they are already in bloom, Schizanthus (butterfly flower), and celosia are good examples.  Hardy annuals are the familiar flowering plants of the summer cottage garden:

Plants such as Calendula (pot marigold) Clarkia, Godetia and Centaurea (cornflower) may be grown from a spring sowing in open ground and will be flowering profusely in early summer.   

Growing Hardy Annuals. (HA)

Any ordinary garden soil is suitable for hardy annuals and in fact for annuals generally.  It does not need to be at all rich, since this only encourages luxuriant growth, which runs counter to the production of flowers.  Annuals do best in light, sandy soil, and they should have this wherever possible.  Good drainage is essential though.

Horticulturally it is wise to incorporate a very generous allowance of humus material such as leaf mould or other decomposing vegetable matter which will help to create humus.  During the decomposition processes of leaves or other organic matter, various acids and other products are created, liberating mineral elements into the soil certain foods essential to plants.  Gases also are generated, which help to keep the soil in a porous, spongy condition beneficial to the roots, and, which assists in the maintenance of that moist condition so essential to healthy growth.

Very hardy annuals may be sown in autumn, not earlier than the last week in August, and not later, even in sheltered spots, than the last week in September.  Autumn-sown plants, if they survive the winter’s frosts, will bloom early in spring.  The situation best suited for autumn sowing is one that is sheltered from strong and cutting winds, but free from shade and well exposed to the sun.  Spring sowings for blooming in summer may be made at any time from the middle of March to the middle of April.  Later sowings for flowering in autumn should be made from mid May to mid June.  The different conditions and climates prevailing across the UK make it impossible to give exact times and details.

To raise annuals for transplanting, sow them n in V-shaped drills about ½ an inch deep and 10 inches apart in the reserve garden or elsewhere, and removed when about ‘hall-grown, to the position in which they are intended to flower; on an average about 9 inches should be left between each plant. They should be firmly planted then well watered in to fix the soil round the roots.  Transplanting annuals, unless very carefully done always has some potential dangers. This can be reduced if they are raised in pots, from which they can be turned out without disturbing the roots. 

Key Points

Hardy annuals

• Generally sown where they are to flower. However, most will transplant quite well, so surplus seedlings from an over-liberal sowing can be moved to other sites.
• Both hardy and half-hardy annuals are best grown in beds where they can be reached easily for hoeing and dead-heading.
• They can be grown in separate beds; alternatively, they can be used to fill spaces between herbaceous plants.
• Hardy annuals should be sown in mid-spring.
• Before you begin, make sure that the soil will crumble to give a tilth — this indicates that it is ready for sowing seeds.
• Sowing in late spring will provide late-summer flowers after many annuals are over.
• Exceptionally early flowers will result from sowing some of the hardiest sorts in the early autumn of the previous year.
• Be prepared for the fact that the cold may kill some of the flowers.
• Rake a general fertilizer into the surface when preparing the seedbed, then use the corner of a hoe to mark out the areas for each type of plant.
• Areas can be irregular interlocking shapes, with repeats of the same plants at intervals rather than large, solitary blocks.
• Rake each patch lightly in one direction to leave parallel lines.
• Scatter the seeds thinly along the furrows left by the rake then draw the rake over the ground at right- angles to the original furrows to cover the seeds.
• Push in sticks or pegs round the edge of the bed at regular intervals and create a net over the bed by criss-crossing black cotton between the pegs to keep off the birds.
• Later, thin overcrowded seedlings.
• Sow sweet peas individually, first soaking the seeds for 24 hours. When the seedlings begin to grow, support them with net or sticks.  

Reminders

• Support floppy plants, such as cornflowers and larkspurs, with twiggy sticks
• Use twigged branches to keep cats off the seedbed.
• When thinning, avoid disturbing nearby seedlings.
• Remove dead blooms every day or two to encourage further flowers.
• If weeds are kept down in the early stages the plants will then tend to smother them 

Growing Half-hardy annuals (HHA)

These are colourful bedding plants which brighten up many English gardens in summer but since they are natives of warmer climates they do not reproduce naturally outdoors in countries that experience cold, wet winters.  So as gardeners we have to intervene in the plant’s natural cycle either by collecting seed in autumn and storing it in a dry warm place in winter, or purchase fresh seed every spring.  To obtain maximum impact from these plants, seedlings should be raised in a warm environment, such as a greenhouse or heated frame, and planted out when all danger of frost is passed. Tagetes (African marigolds), zinnias and lobelia are familiar examples in this group.  Seed of half-hardy annuals may be sown outdoors when all danger of frost is passed, but generally this method does not give such a good show of blooms due to the shortened growing period.

The seeds should be sown in March or April in well-drained pots or pans, in a good quality seed compost mixture, and sheltered in a frame or the pots can be placed with moderate bottom-heat, such as a propagation bench.  The temperature should not rise above 75°F by day or fall below 55°F at night.  Harden-off gradually and remove to flowering position about the middle of May, however delay the removal to the end of the month if the weather is cold and unfavourable. 

Key Points

Half-hardy annuals

Buying plants

• Bedding plants, as half-hardy annuals are often called, are regularly on sale well before it is safe to plant them out.
• If you buy them at this time, place them in a cold frame and cover them at night until the risk of frost is over.
• Whether you buy early or later in the season, always buy compact, bushy plants and avoid those that are already in flower.

Planting out

• Plant half-hardy annuals in soil that has been dug and broken down fairly finely.
• Scatter a dressing of general fertilizer before giving the soil a final raking.
• Water the trays of plants an hour or so before setting them out.
• Using a trowel, set the plants in groups of between six and twelve (or in straight rows if you prefer) with approximately the right spacing between plants.
• Remember to place the tall varieties behind the shorter ones and try to avoid obvious colour clashes.
• Firm the soil around each plant.
• Water them in afterwards, and again whenever the soil shows signs of drying out during the next few weeks. 

Aftercare

• Pinch out the tips of plants that have a central stem this makes them produce many more flowering side-shoots.
• If the weather remains damp after planting, scatter slug pellets around the plants, as their tender young leaves act as a magnet to slugs.
• Keep the soil watered during dry spells, or growth will be checked and flowering will suffer.
• Always give sufficient water to reach the roots.
• Remove dead flowers as often as possible. This can become an overwhelming task in mid-summer, but it does help to prolong flowering.
• A liquid fertilizer watered on to the bed every week or two will also help to keep the plants blooming.

Half-hardy annuals - Reminders

• Half hardy annuals can be raised on a windowsill using a covered propagator.
• They must be protected until the risk of late spring frosts is over.
• Allow plants to harden off gradually before you plant them out, and provide night-time protection if there is a risk of frost.
• ·Moist soil is essential for newly planted half-hardy annuals to encourage root growth
• The roots should extend to their full length when placed in the compost.
• A cold frame provides the intermediate stage between greenhouse and garden.
• Watch for aphids clustering on young shoots and spray them if necessary.
• In town gardens, protect plants against birds and cats until they are well established.