Top of the list this month
• Rake fallen leaves but leave some areas with leaf litter for wildlife to inhabit over winter. Don’t compost any diseased foliage such as rose black spot – dispose of these via council green waste.
• Continue to plant spring-flowering bulbs such as daffodils, crocus and hyacinths before winter sets in, but you can leave planting tulips until next month. Consider naturalising hardy bulbs such as camassia in an area of grass.
• Renovate the lawn by scarifying, aerating and filling in bare patches, then overseed as necessary. October is usually an ideal time to lay turf as the ground is still warm and conditions are moist. Good ground preparation is the key to success.
• Cut back, divide and replant overgrown herbaceous perennials this month.
• Prune climbing roses tying stems in; and in exposed areas cut back long whippy growth of tall shrubs and shrub roses to prevent wind rocking the plants and weakening them.
• Use your home-made compost for an autumn mulch or dig in to improve the soil.
• Plant garlic now in an open, sunny site to be ready for harvest next spring/summer (see above left).
• October is an ideal month to plant trees, shrubs and climbers as the soil is still warm. Leave planting any borderline hardy plants until spring. Now is also the ideal time to move evergreen trees and shrubs. Hold off moving deciduous plants until dormant — after leaf fall.
• Move tender plants such as canna, citrus and young olives into a conservatory or glasshouse. Less hardy plants that are in containers outdoors may need winter protection: be prepared to wrap plants in fleece and bubble wrap the pots if extreme temperatures are forecast.
• In milder areas, sow sweet peas in an unheated glasshouse or cold frame to overwinter, ready early for next spring (in colder areas wait until late March or April).
Plant of the month
Aster 'Little Carlow’ (AGM) is in full flower in October
• A bushy, hardy perennial, 'Little Carlow’ is a hybrid of Aster cordifolius, which produces loose panicles of abundant violet-blue daisy-like flower heads with yellow centres, in early and mid autumn. These pretty flowers also attract pollinating insects.
• The plant grows well in any aspect but prefers full sun to partial shade in a soil that is moderately fertile, moist but well-drained. Height 90cm (36in), spread 45cm (18in). Asters benefit from being mulched annually after being cut back in late autumn.
• Visit the RHS Plant Finder for suppliers (rhs.org.uk/plantfinder).
• The Award of Garden Merit (AGM) is reserved for plants of outstanding garden-worthiness. That is, they are excellent for ordinary use in appropriate conditions. Look out for the AGM logo on plant labels and visit rhs.org.uk/agmplants for more information on which plants have the award.
How to grow garlic
In recent years, garlic has become increasingly popular with gardeners and our Advisory Service answers many enquiries on the subject.
• To grow garlic successfully you need an open, sunny site and a moist but well-drained soil, preferably alkaline.
• On heavier soils plant in modules, overwinter in a cold frame and plant out in spring. £ Don’t overfeed, or the plant will put on too much green growth at the expense of the bulbs. Sulphate of potash at 20g per sq metre (¾oz per sq yd) in February or March will help.
• After planting, garlic needs a cool, one to two-month period at temperatures of 0-10C (32-50F) for good bulb development. Planting in late autumn (late October to November) or in early spring will provide the necessary chilling period.The cultivar dictates the timing so it is important to know the variety name.
• Carefully split the garlic bulb into cloves, making sure the flatter basal plate is facing downwards on planting. Autumn-planted types are best planted with their tips 2in (5cm) below the surface. Spring planting depth is 1in (2.5cm). Allow 6in (15cm) between cloves and 1ft (30cm) between rows.
• Keep moist throughout the season — it is a misconception that garlic likes it hot and dry — the roots need water.
• Lift autumn or winter-planted bulbs in late spring or early summer as soon as the leaves fade and turn yellow. Harvest spring-planted from midsummer to early autumn. Dry bulbs and store in a dry place.
• Visit the RHS Plant Finder for suppliers (rhs.org.uk/plantfinder).
Guide to useful kit
The ultimate in secateurs, Felco secateurs are a worthy investment for keen gardeners. Available in various sizes, with ergonomically designed handles, Felco secateurs are made in Switzerland and have a lifetime guarantee (for amateur use only). The handles are made from forged aluminium and the blades of high-quality hardened steel to give a clean and precise cut. Easy to clean, these secateurs are among the best you can buy. From around £23 (felco.com).
RHS news and events
• Celebrate the harvest, Oct 17-21, as the Grow Your Own Autumn Festival transforms RHS gardens. Festivities include cooking demonstrations and displays of local produce, and a chance to ask RHS experts your burning questions (rhs.org.uk/gardens).
• During half-term, Oct 27-Nov 4, the RHS gardens will be marking Hallowe’en with a range of children’s activities, including pumpkin carving, and scavenger hunts (rhs.org.uk/gardens).
• Come along to Rosemoor for Apple Day on Oct 7. There will be apple displays, cookery demonstrations and apple recipes, planting and cultivation tips and talks. The Kitchen Restaurant will be offering an Apple Day menu (rhs.org.uk/rosemoor).
• A team of RHS experts will be at Harlow Carr, North Yorkshire, Oct 7-8, to share their expertise. Normally a service for members, visitors will be able to get help with gardening questions (rhs.org.uk/harlowcarr).
• The best of the harvest is celebrated at the RHS London Harvest Festival Show, Oct 9-10. See, taste and buy mouth-watering produce and marvel at the giant pumpkins (rhs.org.uk/shows).
• The RHS London Shades of Autumn Show, Oct 23-24, will be packed with autumn planting inspiration. The Lawrence Hall will feature more than 20 specialist nurseries offering a wealth of advice and an enviable selection of plants (rhs.org.uk/shows).
• Wisley will play host to some majestic birds of prey, Oct 27-28, with demonstrations from owls, eagles and other magnificent birds (rhs.org.uk/wisley).
