The garden in September

As the back end of the year approaches, September is the time to clear up the remains of what is left from the summer's flowers, fruit and vegetable crops. The nights are starting to draw in and the leaves will soon start to drop from the trees.

Despite this, it is possible to put winter bedding plants in to fill some of those gaps by dying back perennials.


Herbaceous

• Lift and divide any herbaceous perennials which have become too big and/or congested.

It is not difficult to tell when it's best to divide perennials. The centre of the plant starts to die back and the plant does not flower quite as well as it has in the past. The split clumps will be invigorated next year with far better growth. The clumps can either be re planted further apart, in other parts of the garden, or given to relatives and friends. Either way, when it is re-planted, it would benefit to improve the soil around it to get it off to a good start.

• Support and autumn flowering plants.

This is important as autumn weather can be changable and plants like Japanese anemones, sedums, asters or dahlias can ensure that your prize flowers are not lost in a single gust of wind or heavy rain.

• Dead head and remove dying foliage from perennials and summer bedding plants.

Whilst this is the back end of the year, getting the very most out of your plants is a great plan, besides which, leaving on dying growth can encourage infections.

• Seeds may be collected from perennials and hardy annuals.

Put them in a paper bag (not plastic), with the name of the plant clearly written on the side and store in a cool place, preferably where mice will not be able to get at them.

• Evergreen hedges can be trimmed for the last time this season.
• Plant spring bulbs.
• If you have planted any new plants recently, keep watering them until established.

Trees and Shrubs

• If any deciduous tree or shrub is not in it's correct place, this is a good time to move it.

Before you actually move it, think of the risk involved to the tree. If it is a large plant, the chances of keeping it alive are less good than if it was a smaller specimen. Water the plant well first, then dig it up, leaving a large root ball on it. Plant it in the new hole as soon as possible, staking when necessary.

Climbers

• Prune any climbing roses which have finished flowering.

Tie in the healthy new stems whilst removing dead, diseased and dying stems. If they are still looking good, this can be delayed until October.


Pests and Diseases to look out for

• Powdery mildew if weather is warm.
• Discoloured leaves on perennials: Possible leaf and bud eelworm.
• Phlox: Distorted leaves could indicate the presence of phlox eelworm.
• Chrysanthemums: White rust.
  

General

Clear away remains of finished crops. Order/plant spring bulbs. Cuttings maybe taken from evergreen shrubs, geraniums and hydrangeas. Mildew needs to be kept in check, especially on Asters (Michaelmas Daisy). Any roses need to be dead headed and checked for mildew and greenfly. Prune climbing and rambling roses which have just one round of flowers. Feed Dahlias once a fortnight with a liquid fertilizer. Spray lilies against aphids and botrytis. Soil maybe conditioned by digging it over whilst adding manure.