Autumn clean-Up (Contd) Annuals Clear annuals and biennials when they finish flowering or are browned by frost. Leave seed heads only for drying, the finches or winter show. Weed and dig over, adding compost or manure to revitalize. Any seedling volunteers from Myositis (Forget-me-not), Limnanthes, etc should be pulled or thinned – overcrowding of seedlings results inpoor flowering; it’s easier to get these guys out of the way now than later!
Stakes and Supports Essential in summer, supports can give the garden an uncared-for, unkempt look of despair if left in place all winter. Collect, clean and store stakes and supports from the garden and dispose of used twine. Check wooden structures for any maintenance, and repair and paint over winter.
Tidy Dying Foliage Many perennials will still be flowering; others will have begun to die down. Cut back perennials when plants begin to collapse and become unsightly, trimming away brown, frosted and dying vegetation. While many flower stems will simply pull away, cut more reluctant stems cleanly and remove the dying vegetation.
Remove seed heads of wilful spreaders - before the seed scatters far and wide.in autumn. Soggy, slowly rotting plant materials, especially in wet climates, make ideal homes for slugs, snails, earwigs as well as a breeding ground for fungal diseases. Many leaves have spores of moulds and blackspot - leaving these on the soil reinfects plants next season. (For the same reason, keep your tools clean.) Clean up we must!
Shred and compost the rubbish but avoid composting any diseased material, instead remove this into the rubbish or burning heap.
Leaf fall The glory of autumn, all those deciduous leaves need to be collected and piled for leaf mould. On lawns fallen leaves kill the grass and encourage wretched mosses to grow. On borders and flower beds rotting leaves are a disease risk in wet climates, and provide a haven for slugs and snails in any climate.
Lift and Divide Tender bulbs Tender bulbs, such as dahlias, need to be lifted in cold frosty areas, as they are not hardy even underground. In wet areas tender bulbs can rot in cold damp ground. Lift as flowering ceases and/or frost has touched the foliage. Store dahlias in trays in a cool frost-free environment and hang gladioli in warm well-ventilated place.
Eucomis (pineapple lilies), criniums, clivias and Zantedeschia (callas) can be over-wintered under a mulch layer in most areas, but where winters are long and frosts hard, these should be lifted and re-potted for over-wintering in a frost free greenhouse. Often tender bulbs are best grown in pots and then sunk, pots and all, into the border each summer after the soil has warmed, avoiding annual lifting.
Divide Plants Lift, divide and replant clump-forming perennial plants, such as hemerocallis, in early autumn to allow good root development in new plants before growth stops, setting them up for a good start in the following year. In areas with very severe winters you may want to delay division until spring, when plants are less vulnerable.
Conventional wisdom required division of perennials on a 3-year cycle; nowadays division is only undertaken when a planting scheme gets out of balance or the plant need rejuvenation. Remember that larger clumps of plants are more satisfying than itty-bitty scatterings; so don't make divisions too small and plant in groups of three or more. Cover new shoots well when replanting to protect from frost.
Soil and Mulching Work the Soil After clearing the debris and the leaves, lightly fork over or rake the soil to leave a good friable surface and un-do any compacting from walking on the soil. There are small hand tools suitable for use in densely planted areas. Take care to avoid bulbs and early spring plants that have already retreated underground.
Mulch When you are done, mulch, mulch and mulch. Mulch protects plants from rough climatic conditions, and reduces temperature fluctuations, much like a sunscreen. Marginally hardy perennials, especially, benefit from a cover of mulch, remember to carefully scrape it away from the crown of the plant in spring. Or you can use evergreen branches or a frost cloth to protect marginal perennials over winter.
Mulch helps to stop winter rains leaching nutrients from the soil. An added bonus of using well-rotted compost as a mulch is that it improves fertility and soil structure.
It's Autumn. It's Clean-Up Time While autumn weather allows, and into winter when weather and soil conditions allow, clear, tidy, and rejuvenate your borders. It may seem daunting but working steadily from one end to the garden to the other, it is possible. And extremely rewarding.
Garden Tip: A supermarket or plastic carry bag, hooked over the wheelbarrow handle, is ideal for holding weeds and cut-down plant material to be dumped, rather than composted.
Dealing With Leaves As an alternative to a leaf pile, try using a large hole dug in the ground, as leaves settle you can add more, and then empty next autumn when they have decomposed, refilling the leaf-pit again.
In smaller gardens, where space is at a premium, a large plastic rubbish sack, with aeration holes pierced in the base, will hold decomposing leaves.
Lift tender bulbs, clear dying plants
Delphiniums are many other perennials need regular division
Plant divisions in groups and cover new shoots well
Compost: Empty one bin for mulch while you fill the other with autumn debris
A supermarket or plastic carry bag, hooked over the wheelbarrow handle, is ideal for holding weeds and cut-down plant material to be dumped, rather than composted.
As an alternative to a leaf pile, try using a large hole dug in the ground, as leaves settle you can add more, and then empty next autumn when they have decomposed, refilling the leaf-pit again.
In smaller gardens, where space is at a premium, a large plastic rubbish sack, with aeration holes pierced in the base, will hold decomposing leaves.
