Gardener's diary - September gardening
Our Guide to September Gardening.
September offers an extensive array of blossoming flowers, shrubs and other plants, providing one of the most colourful months in the garden.
Hardy Perennials
Continue with routine tasks and provide support for late flowering perennials.
Now is the right time to prepare for new herbaceous borders. Autumn planting is not advisable in colder areas or even warm areas if the soil is heavy.
Prepare the ground thoroughly by double digging as your plants are going to be in position for 3 years or more Prepare a plan of your border to be ready for next month.
Young plants grown from seed and cuttings can be moved to a permanent position.
Paeonies can be divided if they are becoming too large, although it is better to leave these plants in the same position for as long as possible as they do not like to be moved and may not flower for the next year or two.
Now is the right time to prepare for new herbaceous borders. Autumn planting is not advisable in colder areas or even warm areas if the soil is heavy.
Prepare the ground thoroughly by double digging as your plants are going to be in position for 3 years or more Prepare a plan of your border to be ready for next month.
Young plants grown from seed and cuttings can be moved to a permanent position.
Paeonies can be divided if they are becoming too large, although it is better to leave these plants in the same position for as long as possible as they do not like to be moved and may not flower for the next year or two.
Hardy Annuals
In warmer regions certain hardy annuals can be sown in prepared flower beds and these will flower next year. This includes Iberis (Candytuft) and Papaver rhoeas (annual poppy).
Biennials
Prepare soil for planting. Fork the soil and dig in manure or compost then rake in a dressing of bone meal.
Shrubs
Take cuttings of hardy shrubs. Plant root-balled shrubs in the last week of September or wait until next month. Only do this if the soil is still warm, to encourage development of the root-ball.
Climbers
Plant climbers and wall plants in areas where the soil is still warm. Prune long shoots on Wisteria. Cut back laterals on Pyracantha, leaving new shoots which are needed to add to the shape.
Trees
Don't neglect plants in a late drought, especially young and newly planted trees. A dressing of fertilizer can be beneficial at this point, encouraging ripening of any new growth.
Hedges
Container grown plants can continue to be used and now is the time to complete ground preparation if you are planning on using balled or bare rooted plants in the autumn.
Any healthy established plants can be moved from the middle of the month onwards. This allows roots to establish before the cold weather starts.
A final trim can be given to quick growing plants to tidy up any straggly shoots.
Take cuttings now if you want a supply of inexpensive plants to repair and replace old hedges.
Any healthy established plants can be moved from the middle of the month onwards. This allows roots to establish before the cold weather starts.
A final trim can be given to quick growing plants to tidy up any straggly shoots.
Take cuttings now if you want a supply of inexpensive plants to repair and replace old hedges.
Heathers
Prepare beds for autumn planting. Ensure there is no lime in the soil-heathers prefer an acid soil. Dig in leaf or peat mould but avoid manure.
Take time to plan and design your new bed, including small or low growing conifers for added interest.
Pot rooted cuttings into compost which is a mixture of 7 parts lime-free soil, 3 parts medium grade moss peat and 2 parts sharp sand. Water well and gradually increase the ventilation once they are growing freely. Keep pots frost free and do not allow the soil to become saturated in the early stages of growth.
Take time to plan and design your new bed, including small or low growing conifers for added interest.
Pot rooted cuttings into compost which is a mixture of 7 parts lime-free soil, 3 parts medium grade moss peat and 2 parts sharp sand. Water well and gradually increase the ventilation once they are growing freely. Keep pots frost free and do not allow the soil to become saturated in the early stages of growth.
Bulbs and Corms
Propagate lilies by collecting bulbils that have formed in the leaf axils. Pot up in a mixture of peat and sand.
Plant daffodils, spring flowering crocuses and cyclamens. Now is also the time to plant bulbs for flowering indoors at Christmas. Plant, cover in black polythene and keep in warmth and dark until the shoots are 2.5cm (1 inch) high then move into the light.
Plant daffodils, spring flowering crocuses and cyclamens. Now is also the time to plant bulbs for flowering indoors at Christmas. Plant, cover in black polythene and keep in warmth and dark until the shoots are 2.5cm (1 inch) high then move into the light.
Alpines
Heated structures should be closed overnight to prevent frost but unheated require full ventilation. Gradually reduce watering and continue to check for pests and diseases. Remove shading as required.
Whilst weather is mild is a good time to move plants outside, on a dry day, so all glass can be cleaned thoroughly to provide more light in the winter months.
Collect seeds from late flowering plants to save for sowing later in the season.
Now is the ideal time for constructing new rock gardens before the soil becomes too wet.
Continue with routine tasks.
Whilst weather is mild is a good time to move plants outside, on a dry day, so all glass can be cleaned thoroughly to provide more light in the winter months.
Collect seeds from late flowering plants to save for sowing later in the season.
Now is the ideal time for constructing new rock gardens before the soil becomes too wet.
Continue with routine tasks.
Lawns
Continue mowing if needed but raise the blades on the lawn mower.
New lawns can be sown in milder climates, preferably before the middle of the month. If you have not already done so, add a balanced mixture of fertilizer a few days before you sow.
Check established lawns for moss and if necessary use a moss killer such as lawn sand. Rake regularly to keep thatch in check and remove excess debris.
Improve compacted areas by aeration. Spike lawns the depth of at least half the fork tines length at close spaced intervals and water thoroughly when finished.
Apply a top dressing, a mixture of organic matter, sand and loam, to eliminate any minor uneven levels and improving fertility. Do this when growth has slowed down and conditions are dry.
New lawns can be sown in milder climates, preferably before the middle of the month. If you have not already done so, add a balanced mixture of fertilizer a few days before you sow.
Check established lawns for moss and if necessary use a moss killer such as lawn sand. Rake regularly to keep thatch in check and remove excess debris.
Improve compacted areas by aeration. Spike lawns the depth of at least half the fork tines length at close spaced intervals and water thoroughly when finished.
Apply a top dressing, a mixture of organic matter, sand and loam, to eliminate any minor uneven levels and improving fertility. Do this when growth has slowed down and conditions are dry.
Plants that are in flower in September
Annuals and Biennials:
- Ageratum
- Althaea
- Alyssum
- Amaranthus
- Antirrhinum
- Begonia
- Calceolaria
- Calendula
- Callistephus
- Celosia
- Centaurea
- Chrysanthemum
- Clarkia
- Cleome
- Cobaea
- Convolvulus
- Coreopsis
- Cosmos
- Dahlia
- Dianthus
- Eschscholzia
- Gaillardia
- Gazania
- Godetia
- Gypsophila
- Helianthus
- Helichrysum
- Heliotropium
- Hibiscus
- Impatiens
- Lathyrus
- Lavatera
- Lobelia
- Malope
- Mesambryanthemum
- Molucella
- Nemesia
- Nicotiana
- Nigella
- Papaver
- Petunia
- Phlox
- Rudbeckia
- Salpiglossis
- Salvia
- Scabiosa
- Tagetes
- Zinnia
Border Perennials:
- Acanthus spinosus
- Achillea filipendulina
- Agapanthus africanus
- Anaphalis spp.
- Anenome japonica
- Aster novi-belgii
- Chrysanthemum rubellum
- Cimicifuga foetida
- Clematis heracleifolia
- Cortaderia selloana
- Echinacea purpurea
- Eryngium spp.
- Inula hookeri
- Kniphofia uvaria
- Liatris spicata
- Ligularia dentata
- Liriope muscari
- Lysimachia clethroides
- Lythrum salicaria
- Oenothera missouriensis
- Phlox spp.
- Physalis franchetii
- Physostegia virginiana
- Polygonum affine
- Potentilla hybrids
- Rudbeckia fulgida
- Salvia superba
- Saponaria officinalis
- Schizostylis coccinea
- Sedum spectabile
- Solidago hybrida
- Stokesia laevis
- Tradescantia virginiana
- Viola odorata
Rockery Perennials:
- Acaena microphylla
- Achillea tomentosa
- Androsace lanuginosa
- Astilbe chinensis pumila
- Campanula spp.
- Cyananthus microphyllus
- Dianthus deltoides
- Erigeron mucronatus
- Gentiana sino-ornata
- Geranium cinereum
- Lithospermum diffusum
- Origanum amanum
- Penstemon pinifolius
- Polygonum vaccinifolium
- Potentilla nitida
- Saponaria ocymoides
- Silene maritima
- Sisyrinchium spp.
Bulbs:
- Acidanthera
- Amaryllis
- Begonia
- Canna
- Colchicum
- Crinum
- Crocosmia
- Crocus (Autumn flowering)
- Cyclamen europaeum
- Cyclamen neapolitanum
- Freesia
- Galtonia
- Gladiolus (Hybrids)
- Nerine
- Sternbergia
- Tigridia
Shrubs:
- Abelia grandiflora
- Aralia elata
- Calluna species
- Erica species
- Fuchsia species
- Hebe species
- Hibiscus species
- Hydrangea species
- Hypericum species
- Lespedeza species
- Potentilla species
- Yucca filamentosa
Trees:
- Magnolia grandiflora
- Eucryphia
