The sowing calendar

The Sowing Calendar

Arthur shares with you his sowing calendar, in which he details what to sow and when to sow it.

Stagger your sowing when you don't have a greenhouse. You need to be very selective about what you decide to sow from seed and what you sow as a plug plant.

As soon as a seed has germinated on a windowsill in a seed tray, it moves towards the light. This causes elongation. As a gardener, you want to prevent this from happening, and the easiest way to do this is to sow later than most people would do.

Arthur hardly sows anything in March. Mid-April to the end of June are prime weeks for sowing. The first things are the Panicums, 'Sparkling Fountain' and 'Frost Explosion'. These are sown into a square 9cm pot with a bit of grit mixed in and sprinkled them over the surface of that pot.

Seeds often need daylight to germinate.

Cosmos are very fast to grow. Arthur counts out 15 seeds and sows them into a seed tray, spaced out a good 2 and a half inches apart. You always need to space them out to ensure they've got a room.

In mid-April, he would plant some dahlia tubers like 'Totally Tangerine'. They flower the first week of July. They need a 2-litre pot and the tubers just into the surface of the soil, they'll sprout quite quickly on the windowsill. Provided the compost is moist to the touch when you put the tubers in the pot, you won't need to water them until they start to sprout.

Arthur sows a lot of things in May. Sunflowers can be sown from May to mid-June. Runner beans and pumpkins can be sown in May. The 'Red Millet' seeds can be sown as late as the end of June.

Autumn & Winter

By August you should think about your autumn display and sowing your kale. From mid-December to January, you sow your sweet peas.

Key Tip

Remember to sow fewer rather than sowing loads; this helps you ensure the process is stress-free and that whatever you are sowing is kept healthy and not swamped by loads of seedlings needing loads of space.

Sweet Peas

Sweet peas are classed as a hardy annual, which means they can cope with the cold. Winter sowing allows the seeds to concentrate on the roots rather than growing up. Consequently, when summer comes, they are powerhouses of fragrance and flowering.

Since they are hungry seedlings, they need rich compost. You should make sure you properly fill your deep root trays with compost.

Cloche

A cloche is a bit of an investment. Using a see-through Perspex box turned upside down with a brick on top is an alternative if you are on a limited budget. Ideally, you want something that allows light to pass through, but keeps the wind out.

Early Spring

Things to Sow

• Foliage of kales, fennel and cardoons
• Honesty 'Lunari annua'
• Annual phlox 'Phlox drummondii' (sow undercover)
• Scabious 'Scabiosa atropurpurea' (sow undercover)
• Quaking grass 'Briza maxima'

Important Notes

• Last chance to plant vines
• Last chance to plant bare-root roses
• Finish pruning roses early in the month
• Plant summer bulbs in containers
• Feed your rhododendrons
• Feed your ericaceous shrubs
• Pick off any developing seed-heads from your spring bulbs, leaving the foliage to die back naturally

Mid-Spring

Things to Sow

• Wallflowers and kale
• Cornflowers
• Antirrhinum (Snapdragon) sow undercover
• Nigella (Love-in-a-mist)
• Papaver (Poppy) annuals only, for biennials sow late Spring or Early Summer

Important Notes

• Protect new shoots from slugs and pests
• Spray the new leaves of disease-prone roses
• Put supports in for peonies and your other perennials.
• Plant up your summer hanging baskets but store them in a greenhouse
• Apply liquid feed to tulips, daffodils, and other spring bulbs.

Early Summer

Things to Sow and Look Out For

• The tulip bulbs can be removed delicately
• The alliums should be in full bloom
• The leaves of the cardoon seedlings should have grown
• Aquilegia (Columbine)
• Dianthus (Sweet William, carnation, and pinks)
• Digitalis (Foxglove)

Important Notes

• Lift and store tulip bulbs

Midsummer

Things to Sow and Look Out For

• Re-plant other pots with the summer show of dahlias and annuals.
• Alstroemeria, Achillea, Campanula (Canterbury Bells), Dianthus (Sweet Williams)
• Myosotis sylvatica (Forget-me-nots)
• Nasturtiums
• Coreopsis
• In the greenhouse sow primrose, polyanthus, and pansies

Important Notes

• Liquid feed dahlias
• Take softwood cuttings from shrubs
• Feed and deadhead roses

Summer to Late Autumn

Things to Sow and Look Out For

• Dahlias
• Cosmos
• Sunflowers
• Quick-flowering half-hardy annuals and annual grasses
• Alcea rosea (Hollyhocks, in late Summer)
• Consolida (Larkspur, in late Summer)

Important Notes

• Collect seeds as they ripen from plants
• Take cuttings of shrubby herbs
• Lift and store corms and tubers
• Bring houseplants back indoors
• Lift and store tulip bulbs
• Leave sunflower seed heads for the birds
• Plant evergreen shrubs
• Take hardwood cuttings from ornamental trees and shrubs
• Plant bare-root hedging, trees, roses and shrubs

Winter

Things to Sow

• Foliages of kales, wallflowers, cardoons and fennel, along with birch wigwam supports
• Plant pots with hundreds of bulbs for spring
• Delphinium
• Violas
• Look out for frost, cover your bulbs with a cloche

Important Notes

• Bring terracotta pots indoors or wrap them in bubble wrap to protect them from cracking
• Move potted plants into sheds to protect them from the frost
• Hard prune overgrown shrubs and hedges while they are dormant