Is it autumn or is it still summer? Over the last decade warm weather mixed with occasional rain has placed September firmly into the summer category. Let's hope the nights stay warm and frost free so that we can enjoy the beauty of summer flowers for as long as possible.

THE ORNAMENTAL GARDEN

Even though the weather may remain warm, some bedding plants such as mimulus and salvia run out of steam early and should be replaced with autumn flowering plants as soon as possible. Winter pansies are a great filler for these spaces and do best if they are planted now. The soil is moist and they can develop a good root system before any hard weather comes along. The fine roots of pansies appreciate light soils that have been enriched with garden compost or a bark-based soil conditioner such as Levington Natures Way Soil Improver and Mulch. To encourage these new plants to grow quickly, feed them once a week with Miracle-Gro Plant Food and pinch off any seed heads as soon as they are seen.

Busy Lizzies, petunias, geraniums and some other bedding plants will continue to flower right until the first frost. Continue to dead head these long flowering plants and give them the energy to thrive with Miracle-Gro Plant Food applied once a week. Apply the feed over the leaves as well as around the roots to ensure some of the nutrients are absorbed almost instantly through the leaves.

Once the bedding plants have finished check the bed for perennial weeds such as bindweed, thistles or nettles. If the finished plants are destined for the compost heap you can spray the lot with Roundup GC or Tumbleweed Original Extra Strong to kill the weeds - roots and all. As with all weedkillers, spray on a calm day when rain is not expected. Leave the weeds and bedding plants undisturbed for at least a fortnight so the weedkiller has time to reach the root tips and destroy the whole plant.

Earliest spring bulbs to plant in September and October are the daffodils and narcissi that produce their root system straight away. Bulbs get weaker and become 'blind' if they are not allowed to retain their foliage for a couple of months in the spring and cannot find enough nutrients in the soil. To provide a reserve of nutrients that will be released only when the soil is warm enough, dress the soil with Miracle-Gro Controlled Release Plant Food or Osmocote. This will feed the bulbs in April and May while they are building up strength for future flowering.

Give evergreen hedges another trim so that they are tidy throughout the winter. This is especially important for Leyland conifers that continue to extend their growth. Next year if regular hedge cutting and removal of the trimmings is a big task, spray suitable hedges with the growth regulator called Cutlass.

topical tip

Look out for powdery mildew on Michaelmas daisies (Aster novi-belgii ) and at the first signs of disease spray with a systemic fungicide such as FungusClear

ON THE PATIO

Plant up prepared hyacinths for Christmas flowering using Levington Bulb Fibre Compost. Unlike standard bulb fibre this contains added nutrients for better blooms and a top class wetting agent so that watering of the growing media is easy. To ensure an even display of colourful and perfumed bulbs that are in bloom at the same time pot up the hyacinths in individual pots keeping most of the bulb above the compost surface. After a generous watering store the pots that have been marked with the colour of the flower close together in a plunge bed with high sides. Cover the bulbs with at least 15cm (6in) of composted bark or peat based compost that has been rescued from exhausted growing bags or patio pots. The plunging time of at least 8 weeks will allow the hyacinth to produce a good root system and draw the flower head out of the bulb. At the beginning of December check the bulbs and plant together the ones that show similar growth. Knock the roots out of the pots and plant in a decorative container for display indoors.

There is such a stunning selection of plants available now for use in autumn and winter baskets and containers that many front doors and patios boast more than one winter display. Avoid using a rich compost recommended for potting summer tubs or hanging baskets. These contain too high levels of nutrients for autumn and winter growth and could encourage lanky, lush growth that could be damaged by frosts. Instead use Levington Multi-Purpose Compost - it has enough nutrients for balanced development but not too much to push plants into lush growth. This product also contains a special wetting agent ensuring that excess water passes through the container and that there is good aeration around the root zone to prevent water logging.

To get a display that will last for months plant several types of bulbs and some flowering plants in the same pot. Plant daffodils deepest, followed by hyacinths and crocus. Top off every container with winter flowering bedding. Look out for daisies (Bellis) and winter pansies in all their various colours plus trailing ivies to soften the hard edges and to provide added interest.

LAWNS

As more rain falls in September the lawn will gradually return to active growth. It's too late to give the lawn a long-lasting nitrogen feed designed for application in spring or summer, because the greening effect lasts for months. This sort of product would encourage soft, lush growth right through until November when the grass would be more susceptible to disease and frost damage. Much better to give the lawn a quick tonic with a soluble plant food such as Miracle-Gro Lawn Food that will green the grass and help to fill any bare patches. The greening effect with this soluble plant food will only last for 3 or 4 weeks and by then it will be time to apply a winterizing autumn dressing.

To improve the drainage on lawns that have wet patches fork over the area with a garden fork. This will allow air below the surface and improve root growth.

Re-seed bare patches in the lawn with Evergreen grass seed. Dig the soil surface to relieve compaction and sprinkle the seed over the area. Rake in and water regularly until the new grass is established. A covering of fleece for a few days will encourage germination and protect from birds. There are various mixtures to suit your situation. Use Evergreen Fine Lawn if your lawn contains no ryegrass, Evergreen Shady where the area gets no sun and Evergreen Multi-Purpose for everything else.

topical tip

Continue to cut the grass every week and trim the edges occasionally. Add the cuttings to your compost heap, mixing in other material as it becomes available.

FRUIT

Late varieties of plums, damson and gages will start to ripen in September and will need regular picking. Start to pick the first apples as they colour and ripen. Test for ripening by lifting the apple in the palm of the hand, giving it a gentle twist. If it comes away with the stalk attached then its ready. Pick the fruit over the subsequent weeks, only taking the ripest. Autumn raspberries will still be fruiting and will benefit from a couple of feeds of Miracle-Gro Ericaceous Plant Food a fortnight apart to provide balanced nutrients for good flavoured fruit and iron to prevent any yellowing of the leaves.

topical tip

Stone fruits such as cherries and plums can develop bacterial canker. Diseased branches develop flat cankers that ooze gum and leaves are few and far between. Cut out badly affected branches and spray trees with Murphy Traditional Copper Fungicide in September and again in October.

VEGETABLES

Continue to pick runner beans and French beans while they are still young. When they are almost to the end of their cropping season leave a few pods to mature to provide ripe seed for next year. Remember that F1 hybrids will not come true from saved seed and you will need to buy fresh next year if you want to grow plants with the same vigour and cropping potential. Continue to feed tomatoes with Tomorite every week to help ripen all the fruits that have set. At the end of the month cut down any stems of tomatoes that carry unripe fruit and hang upside down in a garage. Over the next couple of weeks they will gradually ripen and can then be taken to the kitchen for culinary use.

Be prepared to harvest onions when they are fully ripe and dry. To encourage ripening lift each bulb about 2cm with a garden fork to break the roots, and then allow to dry for at least 2 weeks. Use the dried stems to anchor the onions to a rope so that they can hang in a dry airy place all winter.

Harvest maincrop potatoes and carrots on a dry day and leave the dug crop on the soil surface so that the outer skin can dry before being stored away. Potatoes are best stored in a sack in a really dark cool basement where the air circulates freely. Carrots on the other hand can be placed in boxes and stored in layers with peat or bark between them.

As the ground is cleared of crops in the vegetable plot check the area for weeds, especially things with creeping roots such as couch grass (twitch), ground elder and bindweed. If you find these weeds then treat the whole area with a systemic weedkiller such as Roundup GC or Tumbleweed Original Extra Strong before you start digging. Leave the weeds a couple of weeks to absorb the glyphosate right down to the tips of the roots and after this time dig over the area leaving a rough surface for winter frosts to break down.

topical tip

Watch out for populations of grey aphids under the leaves of Brussels sprouts, cabbages and other brassicas. At first signs of attack spray the pest with BugClear or BugClear Gun!. This spray is quick and effective and food crops can be picked and eaten the same day as treatment.

IN THE GREENHOUSE

Keep tomatoes, peppers and aubergines fed every week with Tomorite to ensure full tasty fruiting until the end of the season.

Bring pot-grown chrysanthemum into the greenhouse by about the middle of the month. Control aphids and many other foliar pests using a spray of BugClear Gun! or Polysect Ready to Use Insecticide.

Remove shading from the glass this month and tidy away all pots, containers and trays.

topical tip

Pot up cyclamen corms into individual pots of fresh Levington Plant Protection compost and keep in a draft-free spot either indoors or in the greenhouse.